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Visualizing and Analyzing Java Dependency Graph with Gephi
Gephi comes with tools to analyse properties of a graph.
September 23, 2014
by Peter Huber
· 31,998 Views · 2 Likes
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Spring Batch Tutorial with Spring Boot and Java Configuration
I’ve been working on migrating some batch jobs for Podcastpedia.org to Spring Batch. Before, these jobs were developed in my own kind of way, and I thought it was high time to use a more “standardized” approach. Because I had never used Spring with java configuration before, I thought this were a good opportunity to learn about it, by configuring the Spring Batch jobs in java. And since I am all into trying new things with Spring, why not also throw Spring Boot into the boat… Before you begin with this tutorial I recommend you read first Spring’s Getting started – Creating a Batch Service, because the structure and the code presented here builds on that original. 1. What I’ll build So, as mentioned, in this post I will present Spring Batch in the context of configuring it and developing with it some batch jobs for Podcastpedia.org. Here’s a short description of the two jobs that are currently part of the Podcastpedia-batch project: addNewPodcastJob reads podcast metadata (feed url, identifier, categories etc.) from a flat file transforms (parses and prepares episodes to be inserted with Http Apache Client) the data and in the last step, insert it to the Podcastpedia database and inform the submitter via emailabout it notifyEmailSubscribersJob – people can subscribe to their favorite podcasts on Podcastpedia.orgvia email. For those who did it is checked on a regular basis (DAILY, WEEKLY, MONTHLY) if new episodes are available, and if they are the subscribers are informed via email about those; read from database, expand read data via JPA, re-group it and notify subscriber via email Source code: The source code for this tutorial is available on GitHub – Podcastpedia-batch. Note: Before you start I also highly recommend you read the Domain Language of Batch, so that terms like “Jobs”, “Steps” or “ItemReaders” don’t sound strange to you. 2. What you’ll need A favorite text editor or IDE JDK 1.7 or later Maven 3.0+ 3. Set up the project The project is built with Maven. It uses Spring Boot, which makes it easy to create stand-alone Spring based Applications that you can “just run”. You can learn more about the Spring Boot by visiting theproject’s website. 3.1. Maven build file Because it uses Spring Boot it will have the spring-boot-starter-parent as its parent, and a couple of other spring-boot-starters that will get for us some libraries required in the project: pom.xml of the podcastpedia-batch project 4.0.0 org.podcastpedia.batch podcastpedia-batch 0.1.0 1.1.6.RELEASE 1.7 org.springframework.boot spring-boot-starter-parent 1.1.6.RELEASE org.springframework.boot spring-boot-starter-batch org.springframework.boot spring-boot-starter-data-jpa org.apache.httpcomponents httpclient 4.3.5 org.apache.httpcomponents httpcore 4.3.2 org.apache.velocity velocity 1.7 org.apache.velocity velocity-tools 2.0 org.apache.struts struts-core rome rome 1.0 rome rome-fetcher 1.0 org.jdom jdom 1.1 xerces xercesImpl 2.9.1 mysql mysql-connector-java 5.1.31 org.springframework.boot spring-boot-starter-freemarker org.springframework.boot spring-boot-starter-remote-shell javax.mail mail javax.mail mail 1.4.7 javax.inject javax.inject 1 org.twitter4j twitter4j-core [4.0,) org.springframework.boot spring-boot-starter-test maven-compiler-plugin org.springframework.boot spring-boot-maven-plugin Note: One big advantage of using the spring-boot-starter-parent as the project’s parent is that you only have to upgrade the version of the parent and it will get the “latest” libraries for you. When I started the project spring boot was in version 1.1.3.RELEASE and by the time of finishing to write this post is already at 1.1.6.RELEASE. 3.2. Project directory structure I structured the project in the following way: └── src └── main └── java └── org └── podcastpedia └── batch └── common └── jobs └── addpodcast └── notifysubscribers Note: the org.podcastpedia.batch.jobs package contains sub-packages having specific classes to particular jobs. the org.podcastpedia.batch.jobs.common package contains classes used by all the jobs, like for example the JPA entities that both the current jobs require. 4. Create a batch Job configuration I will start by presenting the Java configuration class for the first batch job: package org.podcastpedia.batch.jobs.addpodcast; import org.podcastpedia.batch.common.configuration.DatabaseAccessConfiguration; import org.podcastpedia.batch.common.listeners.LogProcessListener; import org.podcastpedia.batch.common.listeners.ProtocolListener; import org.podcastpedia.batch.jobs.addpodcast.model.SuggestedPodcast; import org.springframework.batch.core.Job; import org.springframework.batch.core.Step; import org.springframework.batch.core.configuration.annotation.EnableBatchProcessing; import org.springframework.batch.core.configuration.annotation.JobBuilderFactory; import org.springframework.batch.core.configuration.annotation.StepBuilderFactory; import org.springframework.batch.item.ItemProcessor; import org.springframework.batch.item.ItemReader; import org.springframework.batch.item.ItemWriter; import org.springframework.batch.item.file.FlatFileItemReader; import org.springframework.batch.item.file.LineMapper; import org.springframework.batch.item.file.mapping.BeanWrapperFieldSetMapper; import org.springframework.batch.item.file.mapping.DefaultLineMapper; import org.springframework.batch.item.file.transform.DelimitedLineTokenizer; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.context.annotation.Import; import org.springframework.core.io.ClassPathResource; import com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException; @Configuration @EnableBatchProcessing @Import({DatabaseAccessConfiguration.class, ServicesConfiguration.class}) public class AddPodcastJobConfiguration { @Autowired private JobBuilderFactory jobs; @Autowired private StepBuilderFactory stepBuilderFactory; // tag::jobstep[] @Bean public Job addNewPodcastJob(){ return jobs.get("addNewPodcastJob") .listener(protocolListener()) .start(step()) .build(); } @Bean public Step step(){ return stepBuilderFactory.get("step") .chunk(1) //important to be one in this case to commit after every line read .reader(reader()) .processor(processor()) .writer(writer()) .listener(logProcessListener()) .faultTolerant() .skipLimit(10) //default is set to 0 .skip(MySQLIntegrityConstraintViolationException.class) .build(); } // end::jobstep[] // tag::readerwriterprocessor[] @Bean public ItemReader reader(){ FlatFileItemReader reader = new FlatFileItemReader(); reader.setLinesToSkip(1);//first line is title definition reader.setResource(new ClassPathResource("suggested-podcasts.txt")); reader.setLineMapper(lineMapper()); return reader; } @Bean public LineMapper lineMapper() { DefaultLineMapper lineMapper = new DefaultLineMapper(); DelimitedLineTokenizer lineTokenizer = new DelimitedLineTokenizer(); lineTokenizer.setDelimiter(";"); lineTokenizer.setStrict(false); lineTokenizer.setNames(new String[]{"FEED_URL", "IDENTIFIER_ON_PODCASTPEDIA", "CATEGORIES", "LANGUAGE", "MEDIA_TYPE", "UPDATE_FREQUENCY", "KEYWORDS", "FB_PAGE", "TWITTER_PAGE", "GPLUS_PAGE", "NAME_SUBMITTER", "EMAIL_SUBMITTER"}); BeanWrapperFieldSetMapper fieldSetMapper = new BeanWrapperFieldSetMapper(); fieldSetMapper.setTargetType(SuggestedPodcast.class); lineMapper.setLineTokenizer(lineTokenizer); lineMapper.setFieldSetMapper(suggestedPodcastFieldSetMapper()); return lineMapper; } @Bean public SuggestedPodcastFieldSetMapper suggestedPodcastFieldSetMapper() { return new SuggestedPodcastFieldSetMapper(); } /** configure the processor related stuff */ @Bean public ItemProcessor processor() { return new SuggestedPodcastItemProcessor(); } @Bean public ItemWriter writer() { return new Writer(); } // end::readerwriterprocessor[] @Bean public ProtocolListener protocolListener(){ return new ProtocolListener(); } @Bean public LogProcessListener logProcessListener(){ return new LogProcessListener(); } } The @EnableBatchProcessing annotation adds many critical beans that support jobs and saves us configuration work. For example you will also be able to @Autowired some useful stuff into your context: a JobRepository (bean name “jobRepository”) a JobLauncher (bean name “jobLauncher”) a JobRegistry (bean name “jobRegistry”) a PlatformTransactionManager (bean name “transactionManager”) a JobBuilderFactory (bean name “jobBuilders”) as a convenience to prevent you from having to inject the job repository into every job, as in the examples above a StepBuilderFactory (bean name “stepBuilders”) as a convenience to prevent you from having to inject the job repository and transaction manager into every step The first part focuses on the actual job configuration: @Bean public Job addNewPodcastJob(){ return jobs.get("addNewPodcastJob") .listener(protocolListener()) .start(step()) .build(); } @Bean public Step step(){ return stepBuilderFactory.get("step") .chunk(1) //important to be one in this case to commit after every line read .reader(reader()) .processor(processor()) .writer(writer()) .listener(logProcessListener()) .faultTolerant() .skipLimit(10) //default is set to 0 .skip(MySQLIntegrityConstraintViolationException.class) .build(); } The first method defines a job and the second one defines a single step. As you’ve read in The Domain Language of Batch, jobs are built from steps, where each step can involve a reader, a processor, and a writer. In the step definition, you define how much data to write at a time (in our case 1 record at a time). Next you specify the reader, processor and writer. 5. Spring Batch processing units Most of the batch processing can be described as reading data, doing some transformation on it and then writing the result out. This mirrors somehow the Extract, Transform, Load (ETL) process, in case you know more about that. Spring Batch provides three key interfaces to help perform bulk reading and writing: ItemReader, ItemProcessor and ItemWriter. 5.1. Readers ItemReader is an abstraction providing the mean to retrieve data from many different types of input: flat files, xml files, database, jms etc., one item at a time. See the Appendix A. List of ItemReaders and ItemWriters for a complete list of available item readers. In the Podcastpedia batch jobs I use the following specialized ItemReaders: 5.1.1. FlatFileItemReader which, as the name implies, reads lines of data from a flat file that typically describe records with fields of data defined by fixed positions in the file or delimited by some special character (e.g. Comma). This type of ItemReader is being used in the first batch job, addNewPodcastJob. The input file used is named suggested-podcasts.in, resides in the classpath (src/main/resources) and looks something like the following: FEED_URL; IDENTIFIER_ON_PODCASTPEDIA; CATEGORIES; LANGUAGE; MEDIA_TYPE; UPDATE_FREQUENCY; KEYWORDS; FB_PAGE; TWITTER_PAGE; GPLUS_PAGE; NAME_SUBMITTER; EMAIL_SUBMITTER http://www.5minutebiographies.com/feed/; 5minutebiographies; people_society, history; en; Audio; WEEKLY; biography, biographies, short biography, short biographies, 5 minute biographies, five minute biographies, 5 minute biography, five minute biography; https://www.facebook.com/5minutebiographies;https://twitter.com/5MinuteBios; ; Adrian Matei; [email protected] http://notanotherpodcast.libsyn.com/rss; NotAnotherPodcast; entertainment; en; Audio; WEEKLY; Comedy, Sports, Cinema, Movies, Pop Culture, Food, Games; https://www.facebook.com/notanotherpodcastusa;https://twitter.com/NAPodcastUSA;https://plus.google.com/u/0/103089891373760354121/posts; Adrian Matei; [email protected] As you can see the first line defines the names of the “columns”, and the following lines contain the actual data (delimited by “;”), that needs translating to domain objects relevant in the context. Let’s see now how to configure the FlatFileItemReader: @Bean public ItemReader reader(){ FlatFileItemReader reader = new FlatFileItemReader(); reader.setLinesToSkip(1);//first line is title definition reader.setResource(new ClassPathResource("suggested-podcasts.in")); reader.setLineMapper(lineMapper()); return reader; } You can specify, among other things, the input resource, the number of lines to skip, and a line mapper. 5.1.1.1. LineMapper The LineMapper is an interface for mapping lines (strings) to domain objects, typically used to map lines read from a file to domain objects on a per line basis. For the Podcastpedia job I used the DefaultLineMapper, which is two-phase implementation consisting of tokenization of the line into a FieldSet followed by mapping to item: @Bean public LineMapper lineMapper() { DefaultLineMapper lineMapper = new DefaultLineMapper(); DelimitedLineTokenizer lineTokenizer = new DelimitedLineTokenizer(); lineTokenizer.setDelimiter(";"); lineTokenizer.setStrict(false); lineTokenizer.setNames(new String[]{"FEED_URL", "IDENTIFIER_ON_PODCASTPEDIA", "CATEGORIES", "LANGUAGE", "MEDIA_TYPE", "UPDATE_FREQUENCY", "KEYWORDS", "FB_PAGE", "TWITTER_PAGE", "GPLUS_PAGE", "NAME_SUBMITTER", "EMAIL_SUBMITTER"}); BeanWrapperFieldSetMapper fieldSetMapper = new BeanWrapperFieldSetMapper(); fieldSetMapper.setTargetType(SuggestedPodcast.class); lineMapper.setLineTokenizer(lineTokenizer); lineMapper.setFieldSetMapper(suggestedPodcastFieldSetMapper()); return lineMapper; } the DelimitedLineTokenizer splits the input String via the “;” delimiter. if you set the strict flag to false then lines with less tokens will be tolerated and padded with empty columns, and lines with more tokens will simply be truncated. the columns names from the first line are set lineTokenizer.setNames(...); and the fieldMapper is set (line 14) Note: The FieldSet is an “interface used by flat file input sources to encapsulate concerns of converting an array of Strings to Java native types. A bit like the role played by ResultSet in JDBC, clients will know the name or position of strongly typed fields that they want to extract.“ 5.1.1.2. FieldSetMapper The FieldSetMapper is an interface that is used to map data obtained from a FieldSet into an object. Here’s my implementation which maps the fieldSet to the SuggestedPodcast domain object that will be further passed to the processor: public class SuggestedPodcastFieldSetMapper implements FieldSetMapper { @Override public SuggestedPodcast mapFieldSet(FieldSet fieldSet) throws BindException { SuggestedPodcast suggestedPodcast = new SuggestedPodcast(); suggestedPodcast.setCategories(fieldSet.readString("CATEGORIES")); suggestedPodcast.setEmail(fieldSet.readString("EMAIL_SUBMITTER")); suggestedPodcast.setName(fieldSet.readString("NAME_SUBMITTER")); suggestedPodcast.setTags(fieldSet.readString("KEYWORDS")); //some of the attributes we can map directly into the Podcast entity that we'll insert later into the database Podcast podcast = new Podcast(); podcast.setUrl(fieldSet.readString("FEED_URL")); podcast.setIdentifier(fieldSet.readString("IDENTIFIER_ON_PODCASTPEDIA")); podcast.setLanguageCode(LanguageCode.valueOf(fieldSet.readString("LANGUAGE"))); podcast.setMediaType(MediaType.valueOf(fieldSet.readString("MEDIA_TYPE"))); podcast.setUpdateFrequency(UpdateFrequency.valueOf(fieldSet.readString("UPDATE_FREQUENCY"))); podcast.setFbPage(fieldSet.readString("FB_PAGE")); podcast.setTwitterPage(fieldSet.readString("TWITTER_PAGE")); podcast.setGplusPage(fieldSet.readString("GPLUS_PAGE")); suggestedPodcast.setPodcast(podcast); return suggestedPodcast; } } 5.2. JdbcCursorItemReader In the second job, notifyEmailSubscribersJob, in the reader, I only read email subscribers from a single database table, but further in the processor a more detailed read(via JPA) is executed to retrieve all the new episodes of the podcasts the user subscribed to. This is a common pattern employed in the batch world. Follow this link for more Common Batch Patterns. For the initial read, I chose the JdbcCursorItemReader, which is a simple reader implementation that opens a JDBC cursor and continually retrieves the next row in the ResultSet: @Bean public ItemReader notifySubscribersReader(){ JdbcCursorItemReader reader = new JdbcCursorItemReader(); String sql = "select * from users where is_email_subscriber is not null"; reader.setSql(sql); reader.setDataSource(dataSource); reader.setRowMapper(rowMapper()); return reader; } Note I had to set the sql, the datasource to read from and a RowMapper. 5.2.1. RowMapper The RowMapper is an interface used by JdbcTemplate for mapping rows of a Result’set on a per-row basis. My implementation of this interface, , performs the actual work of mapping each row to a result object, but I don’t need to worry about exception handling: public class UserRowMapper implements RowMapper { @Override public User mapRow(ResultSet rs, int rowNum) throws SQLException { User user = new User(); user.setEmail(rs.getString("email")); return user; } } 5.2. Writers ItemWriter is an abstraction that represents the output of a Step, one batch or chunk of items at a time. Generally, an item writer has no knowledge of the input it will receive next, only the item that was passed in its current invocation. The writers for the two jobs presented are quite simple. They just use external services to send email notifications and post tweets on Podcastpedia’s account. Here is the implementation of the ItemWriterfor the first job – addNewPodcast: package org.podcastpedia.batch.jobs.addpodcast; import java.util.Date; import java.util.List; import javax.inject.Inject; import javax.persistence.EntityManager; import org.podcastpedia.batch.common.entities.Podcast; import org.podcastpedia.batch.jobs.addpodcast.model.SuggestedPodcast; import org.podcastpedia.batch.jobs.addpodcast.service.EmailNotificationService; import org.podcastpedia.batch.jobs.addpodcast.service.SocialMediaService; import org.springframework.batch.item.ItemWriter; import org.springframework.beans.factory.annotation.Autowired; public class Writer implements ItemWriter{ @Autowired private EntityManager entityManager; @Inject private EmailNotificationService emailNotificationService; @Inject private SocialMediaService socialMediaService; @Override public void write(List items) throws Exception { if(items.get(0) != null){ SuggestedPodcast suggestedPodcast = items.get(0); //first insert the data in the database Podcast podcast = suggestedPodcast.getPodcast(); podcast.setInsertionDate(new Date()); entityManager.persist(podcast); entityManager.flush(); //notify submitter about the insertion and post a twitt about it String url = buildUrlOnPodcastpedia(podcast); emailNotificationService.sendPodcastAdditionConfirmation( suggestedPodcast.getName(), suggestedPodcast.getEmail(), url); if(podcast.getTwitterPage() != null){ socialMediaService.postOnTwitterAboutNewPodcast(podcast, url); } } } private String buildUrlOnPodcastpedia(Podcast podcast) { StringBuffer urlOnPodcastpedia = new StringBuffer( "http://www.podcastpedia.org"); if (podcast.getIdentifier() != null) { urlOnPodcastpedia.append("/" + podcast.getIdentifier()); } else { urlOnPodcastpedia.append("/podcasts/"); urlOnPodcastpedia.append(String.valueOf(podcast.getPodcastId())); urlOnPodcastpedia.append("/" + podcast.getTitleInUrl()); } String url = urlOnPodcastpedia.toString(); return url; } } As you can see there’s nothing special here, except that the write method has to be overriden and this is where the injected external services EmailNotificationService and SocialMediaService are used to inform via email the podcast submitter about the addition to the podcast directory, and if a Twitter page was submitted a tweet will be posted on the Podcastpedia’s wall. You can find detailed explanation on how to send email via Velocity and how to post on Twitter from Java in the following posts: How to compose html emails in Java with Spring and Velocity How to post to Twittter from Java with Twitter4J in 10 minutes 5.3. Processors ItemProcessor is an abstraction that represents the business processing of an item. While theItemReader reads one item, and the ItemWriter writes them, the ItemProcessor provides access to transform or apply other business processing. When using your own Processors you have to implement the ItemProcessor interface, with its only method O process(I item) throws Exception, returning a potentially modified or a new item for continued processing. If the returned result is null, it is assumed that processing of the item should not continue. While the processor of the first job requires a little bit of more logic, because I have to set the etag andlast-modified header attributes, the feed attributes, episodes, categories and keywords of the podcast: public class SuggestedPodcastItemProcessor implements ItemProcessor { private static final int TIMEOUT = 10; @Autowired ReadDao readDao; @Autowired PodcastAndEpisodeAttributesService podcastAndEpisodeAttributesService; @Autowired private PoolingHttpClientConnectionManager poolingHttpClientConnectionManager; @Autowired private SyndFeedService syndFeedService; /** * Method used to build the categories, tags and episodes of the podcast */ @Override public SuggestedPodcast process(SuggestedPodcast item) throws Exception { if(isPodcastAlreadyInTheDirectory(item.getPodcast().getUrl())) { return null; } String[] categories = item.getCategories().trim().split("\\s*,\\s*"); item.getPodcast().setAvailability(org.apache.http.HttpStatus.SC_OK); //set etag and last modified attributes for the podcast setHeaderFieldAttributes(item.getPodcast()); //set the other attributes of the podcast from the feed podcastAndEpisodeAttributesService.setPodcastFeedAttributes(item.getPodcast()); //set the categories List categoriesByNames = readDao.findCategoriesByNames(categories); item.getPodcast().setCategories(categoriesByNames); //set the tags setTagsForPodcast(item); //build the episodes setEpisodesForPodcast(item.getPodcast()); return item; } ...... } the processor from the second job uses the ‘Driving Query’ approach, where I expand the data retrieved from the Reader with another “JPA-read” and I group the items on podcasts with episodes so that it looks nice in the emails that I am sending out to subscribers: @Scope("step") public class NotifySubscribersItemProcessor implements ItemProcessor { @Autowired EntityManager em; @Value("#{jobParameters[updateFrequency]}") String updateFrequency; @Override public User process(User item) throws Exception { String sqlInnerJoinEpisodes = "select e from User u JOIN u.podcasts p JOIN p.episodes e WHERE u.email=?1 AND p.updateFrequency=?2 AND" + " e.isNew IS NOT NULL AND e.availability=200 ORDER BY e.podcast.podcastId ASC, e.publicationDate ASC"; TypedQuery queryInnerJoinepisodes = em.createQuery(sqlInnerJoinEpisodes, Episode.class); queryInnerJoinepisodes.setParameter(1, item.getEmail()); queryInnerJoinepisodes.setParameter(2, UpdateFrequency.valueOf(updateFrequency)); List newEpisodes = queryInnerJoinepisodes.getResultList(); return regroupPodcastsWithEpisodes(item, newEpisodes); } ....... } Note: If you’d like to find out more how to use the Apache Http Client, to get the etag and last-modifiedheaders, you can have a look at my post – How to use the new Apache Http Client to make a HEAD request 6. Execute the batch application Batch processing can be embedded in web applications and WAR files, but I chose in the beginning the simpler approach that creates a standalone application, that can be started by the Java main() method: package org.podcastpedia.batch; //imports ...; @ComponentScan @EnableAutoConfiguration public class Application { private static final String NEW_EPISODES_NOTIFICATION_JOB = "newEpisodesNotificationJob"; private static final String ADD_NEW_PODCAST_JOB = "addNewPodcastJob"; public static void main(String[] args) throws BeansException, JobExecutionAlreadyRunningException, JobRestartException, JobInstanceAlreadyCompleteException, JobParametersInvalidException, InterruptedException { Log log = LogFactory.getLog(Application.class); SpringApplication app = new SpringApplication(Application.class); app.setWebEnvironment(false); ConfigurableApplicationContext ctx= app.run(args); JobLauncher jobLauncher = ctx.getBean(JobLauncher.class); if(ADD_NEW_PODCAST_JOB.equals(args[0])){ //addNewPodcastJob Job addNewPodcastJob = ctx.getBean(ADD_NEW_PODCAST_JOB, Job.class); JobParameters jobParameters = new JobParametersBuilder() .addDate("date", new Date()) .toJobParameters(); JobExecution jobExecution = jobLauncher.run(addNewPodcastJob, jobParameters); BatchStatus batchStatus = jobExecution.getStatus(); while(batchStatus.isRunning()){ log.info("*********** Still running.... **************"); Thread.sleep(1000); } log.info(String.format("*********** Exit status: %s", jobExecution.getExitStatus().getExitCode())); JobInstance jobInstance = jobExecution.getJobInstance(); log.info(String.format("********* Name of the job %s", jobInstance.getJobName())); log.info(String.format("*********** job instance Id: %d", jobInstance.getId())); System.exit(0); } else if(NEW_EPISODES_NOTIFICATION_JOB.equals(args[0])){ JobParameters jobParameters = new JobParametersBuilder() .addDate("date", new Date()) .addString("updateFrequency", args[1]) .toJobParameters(); jobLauncher.run(ctx.getBean(NEW_EPISODES_NOTIFICATION_JOB, Job.class), jobParameters); } else { throw new IllegalArgumentException("Please provide a valid Job name as first application parameter"); } System.exit(0); } } The best explanation for SpringApplication-, @ComponentScan- and @EnableAutoConfiguration-magic you get from the source – Getting Started – Creating a Batch Service: “The main() method defers to the SpringApplication helper class, providing Application.class as an argument to its run() method. This tells Spring to read the annotation metadata from Application and to manage it as a component in the Spring application context. The @ComponentScan annotation tells Spring to search recursively through theorg.podcastpedia.batchpackage and its children for classes marked directly or indirectly with Spring’s @Component annotation. This directive ensures that Spring finds and registers BatchConfiguration, because it is marked with @Configuration, which in turn is a kind of @Component annotation. The @EnableAutoConfiguration annotation switches on reasonable default behaviors based on the content of your classpath. For example, it looks for any class that implements the CommandLineRunner interface and invokes its run() method.” Execution construction steps: the JobLauncher, which is a simple interface for controlling jobs, is retrieved from the ApplicationContext. Remember this is automatically made available via the@EnableBatchProcessing annotation. now based on the first parameter of the application (args[0]), I will retrieve the correspondingJob from the ApplicationContext then the JobParameters are prepared, where I use the current date - .addDate("date", new Date()), so that the job executions are always unique. once everything is in place, the job can be executed: JobExecution jobExecution = jobLauncher.run(addNewPodcastJob, jobParameters); you can use the returned jobExecution to gain access to BatchStatus, exit code, or job name and id. Note: I highly recommend you read and understand the Meta-Data Schema for Spring Batch. It will also help you better understand the Spring Batch Domain objects. 6.1. Running the application on dev and prod environments To be able to run the Spring Batch / Spring Boot application on different environments I make use of the Spring Profiles capability. By default the application runs with development data (database). But if I want the job to use the production database I have to do the following: provide the following environment argument -Dspring.profiles.active=prod have the production database properties configured in the application-prod.properties file in the classpath, right besides the default application.properties file Summary In this tutorial we’ve learned how to configure a Spring Batch project with Spring Boot and Java configuration, how to use some of the most common readers in batch processing, how to configure some simple jobs, and how to start Spring Batch jobs from a main method. Note: As I mentioned, I am fairly new to Spring Batch, and especially to Spring Boot and Spring Configuration with Java, so if you see any potential for improvement (code, job design etc.) please make a pull request or leave a comment below. Thanks a lot.
September 9, 2014
by Adrian Matei
· 146,346 Views · 7 Likes
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Securing JBoss EAP 6 - Implementing SSL
Security is one of the most important features while running a JBoss server in a production environment. Implementing SSL and securing communications is a must do, to avoid malicious use. This blogs details the steps you could take to secure JBoss EAP 6 running in Domain mode. These are probably documented by RedHat but the documentation seems a bit scattered. The idea behind this blog is to put together everything in one place. In Order to enhance security in JBoss EAP 6, SSL/encryption can be implemented for the following Admin console access – enable https access for admin console Domain Controller – Host controller communication – Communication between the main domain controller and all the other host controllers should be secured. Jboss CLI – enable ssl for the command line interface The below example uses a single keystore being both the key and truststore and also uses CA signed certificates. You could use self-signed certificates and/or separated keystores and truststores if required. Create the keystores (certificates for each of the servers) keytool -genkeypair -alias testServer.prd -keyalg RSA -keysize 2048 -validity 730 -keystore testServer.prd.jks Generate a certificate signing request (CSR) for the Java keystore keytool -certreq -alias testServer.prd -keystore testServer.prd.jks -file testServer.prd.csr Get the CSR signed by the Certificate Authorities Import a root or intermediate CA certificate to the existing Java keystore keytool -import -trustcacerts -alias root -file rootCA.crt -keystore testServer.prd.jks Import the signed primary certificate to the existing Java keystore. Keytool -importcert -keystore testServer.prd.jks -trustcacerts -alias testServer.prd -file testServer.prd.crt Repeat steps 1-6 for each of the servers. In order to establish trust between the master and slave hosts, Import the signed certificates of all the (slave) servers that the Domain Controller must trust onto the Domain Controllers Keystore keytool -importcert -keystore testServer.prd.jks -trustcacerts -alias slaveServer.prd -file slaveServers.prd.crt repeat step for all slave hosts. Import the signed certificate of the Domain controller onto the slave hosts keytool -importcert -keystore slaveServer.prd.jks -trustcacerts -alias testServer.prd -file testServer.prd.crt repeat steps for all slave hosts This has be to done because (as per RedHat’s Documentation) There is a problem with this methodology when trying to configure one way SSL between the servers, because there the HC's and the DC (depending on what action is being performed) switch roles (client, server). Because of this one way SSL configuration will not work and it is recommended that if you need SSL between these two endpoints that you configure two way SSL Once this is done, we now have signed certificates loaded onto the java keystore. In Jboss EAP 6 , the http-interface which provides access to the admin console, by default uses the ManagementRealm to provide file based authentication. (mgmt.-users.properties).The next step is to modify the configurations in the host.xml, to make the ManagementRealm use the certificates we created above. The host.xml should be modified to look like: view source print? 01. 02. 03. 04. 05. 06. 07. 08. 09. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42. 43. On the Slave hosts, In addition to the above configuration, the following needs to be changed view source print? 1. 2. 3. " 4. 5. Once you make the above changes and restart the servers, you should be able to access the admin console via https. https://testServer.prd:9443/console Finally, in order to secure cli authentication Modify /opt/jboss/jboss-eap-6.1/bin/jboss-cli.xml for each server and add view source print? 01. 02. 03. testServer.prd 04. 05. /opt/jboss/jboss-eap-6.1/domain/configuration/testServer.prd.jks 06. 07. xxxx 08. 09. /opt/jboss/jboss-eap-6.1/domain/configuration/testServer.prd.jks 10. 11. xxxx 12. 13. true 14. 15.
August 28, 2014
by Arvind Anandam
· 11,480 Views
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"How Thin is Thin?" An Example of Effective Story Slicing
Graphene is pure carbon in the form of a very thin, nearly transparent sheet, one atom thick. It is remarkably strong for its very low weight and it conducts heat and electricity with great efficiency. Wikipedia If you have spent any time at all working in an Agile software development environment, you've heard the mantra to split your Stories as thin as you possibly can while still delivering value. This is indeed great advice, but the term "thin" is relative - our notion of what thin means is anchored by our previous experience! To help communicate what I mean when I say that Stories should be thinly sliced, I'm going to provide examples from a recent client who was building a relatively standard system for entering orders from their wholesale customers. To start, here's a very simplified model of the entities we'll be working with (using GML - the Galactic Modeling Language). In plain language, the system creates Orders, which have a Customer and from 1 to some number of Products. For initial planning, the team (consisting of developers, QA person, business analyst and product owner) used Jeff Patton's Story Mapping technique to determine what work the salespeople did at a relatively high level. Not surprisingly, the group determined that creating an Order was the most fundamental part of the system! So we started with a simple sticky note with the title Create Order. Note that there wasn't any other descriptive text, no acceptance criteria, no indication of performance requirements, or even mention of how someone using the system would actually create the order. At this point, we simply didn't need all that - we just needed a placeholder for the conversations that were required for the action of creating orders. Everyone in the group knew that an order would need a customer and some number of products. When I asked what the first Story should be, reminding them that it should be very, very thin, the first suggestion was to have the user select a customer from a list, select products from a list, and save the order. I asked if it was possible to make that story even thinner, and received puzzled looks. I followed with another question - why did we need to select a customer at this point, or even products for that matter? More puzzled looks. Couldn't we just hard-code a customer ID and a single product SKU? More puzzled looks. Another question - if we presented a simple page with a button that when pressed created the order in our database with a hard-coded customer ID and a single, hard-coded product SKU, what percentage of the overall system infrastructure would be fleshed out. That was the point at which people started to understand. The response I received was, "Almost all of it... we need to render a page, capture the submit action, write the order to an Orders table, the product to the Order Lines table and the customer & product to the Customers and Products tables respectively". My response was, "Great!! But it's still a little too thick." More puzzled looks... how could that story be made any thinner? I asked, "Why do we need tables for Customers and Products right now?" More puzzled looks, followed by a sheepish, "Um, because...". The need to create those tables was an assumption at that point. Everyone in the room, myself included, knew that the database would have Customers and Products tables at some point, but we just didn't need them right now. All that was required from a persistence perspective was the Orders and Order Lines tables. Someone asked, "How do we know that the Customer ID and Product SKU are valid?" My response was, "We don't! And at this point, we don't care!" This is another way to split stories - assume the happy path where everything is valid, and build validation and error-handling later. So, this very thin story became, The acceptance criteria for the story were very simple as well: When you navigate to the page index.html, it should be displayed with a Submit button When the Submit button is clicked, the application creates one row in the Order table with a Customer ID of XXX, and one row in the Order Line table with a Product ID of YYY. Note that I could have gone even further and argued that we didn't even need the database yet. We could have simply used a flat file and broken all the rules of relational data modeling by putting all the Order and Order Line data in a single line in the file. Why? BECAUSE WE DIDN'T NEED IT YET! However, in the interest of establishing the overall architecture early, we decided to proceed with the database. It did add some complexity to the story, but it was on the order of hours rather than days or weeks. We also "gold-plated" the story to an extent by providing a rudimentary confirmation page that was displayed after submitting the Order. After the group created this one, simple, thin story with hard-coded values, the next steps were to gradually replace the hard-coding with the selections and searches that you would expect in this type of application. Subsequent stories were, You can now see the progression where the creation of an Order is gradually built out using very thin slices of functionality. Also note that the last two stories, which "wire up" the selection of Customers and Products to an external web service, could be implemented in either order - there is nothing in the story that indicates a dependency on anything else. Splitting Techniques In these stories we used several common splitting techniques: Hard coding values; Simple interface; Defer validation; Zero, then One, then Many (with the Products); Defer complexity. This is only a small handful of the available techniques, but it gave the group a powerful way to work in very, very small increments while still delivering some value with each one. We Can't Ship That!! The moment I suggested the first story with all the hard-coding, I was challenged by the group. Why would you want to build something that isn't production-worthy? The answer is that some aspects of the feature aren't production worthy when you look at the story in isolation. However, the whole concept of a Minimal Viable Product or Minimal Viable Feature is each consists of 1 to many smaller slices (stories in our case) that have been built together to provide enough value to warrant the cost of being put into production. The Product Owner or Product Manager is the person who decides when enough value has accrued to meet that threshold. The Benefits of Thin Slicing I've provide a number of examples from a real-world project but haven't really dug into the reasons why this is a good approach. There are a number of them: You are deferring design decisions as long as possible which gives you more options when it does come time to implement a Story; Having options also allows the Product Owner/Manager to defer business decisions as long as possible, providing the ability to make changes to the product that better suit the actual needs of the business; Thin slices (in conjunction with acceptance criteria) help prevent assumptions which can lead to bloated Stories that are seemingly never done, Agile's version of scope creep; Thin slices are much easier to verify since they are only providing a small increment of functionality beyond what has already been implemented; Thin slices allow a product to be reviewed sooner by both the Product Owner/Manager and users/stakeholders, such that their feedback can be incorporated sooner in the process; Thin slices allow the Product Owner/Manager decides to change or drop a Story without the burden of the Sunk Cost Fallacy. While these are all great reasons to split Stories into thin slices, here's the one that my experience suggests is by far the most important: With Stories sliced as thinly as possible, they all become nearly the same size in terms of effort. Therefore, no estimation of individual Stories is required and a team's capacity can simply be derived by counting the number of Stories completed for some unit of time. That means no haggling over whether a Story is a 3 or 5 on the modified Fibonacci series many teams use for sizing Stories. It means that the need for spending any time estimating individual Stories is no longer required, an activity that is downright painful for some groups. The group from which these examples came was in the situation where there was a hard release date to be met. This stories gave the Product Owner/Manager the ability to easily tweak the what was and wasn't going to be in that initial release and, in several cases which features could be released partially completed. If a group is in the situation where they are being asked for an estimate of when some work could be completed, my experience has also been that Story Mapping coupled with a technique called Blink Estimation provides a high-level estimate of the overall work that's much more grounded in reality. Once a group begins working on thinly-sliced Stories, you begin to have data points with respect to how many they can complete per some unit of time. Those real numbers can then be used to make better business decisions, and deliver a product without the pressure of Crunch Time. Conclusion The group with whom I worked for this example system never spent any time estimating individual Stories. Ever. There were some instances where a Story was larger than it first appeared, but those were either balanced out by Stories that were very small, or by further splitting. Like the graphene example at the beginning of the post, thin stories have remarkable properties far beyond the fact that they are just "thin". The value gained by learning how to split Stories effectively is enormous owing to the flexibility it provides by deferring decisions as long as possible and the removal of the need to estimate at a granular level. Splitting Stories this thin isn't really a specialized skill - it's something that can be learned by anyone in any domain. If you need help learning this technique, let's have a chat.
August 27, 2014
by Dave Rooney
· 35,870 Views
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Remote JMX Monitoring of a Mule Instance
in this post i will describe how to enable monitoring of a remote mule instance using jmx. in addition i will also enable the mx4j web interface that will expose the jmx properties of the mule instance in a web application and i will install the jolokia mule agent, which makes it possible to use hawtio to monitor the mule instance. enabling jmx for a mule instance using a mule application as of writing this, the finest granularity for which jmx monitoring can be enabled is an entire mule instance. thus it is not possible to enable jmx monitoring per application basis in a mule instance. this of course has advantages and disadvantages and we are going to use this fact to our advantage by deploying an application to a mule server that does nothing but enable jmx monitoring for the server. create a directory named “mulejmxenabler”. in this new directory, create a file named “mule-config.xml” with the following contents: in the above file, replace the ip address “192.168.1.73” with either the external ip address or the dns name of the computer running the mule server that you want to monitor. optionally, you may change the port number 1096 to any port that you rather use. deploy the application by copying the directory mulejmxenabler with its contents to the apps directory of the mule instance that is to be monitored. verify that the application was successfully deployed in the log of the mule instance (mule.log if you are using the community edition, mule_ee.log if you are using the enterprise edition). you should see something like this: info 2014-08-24 16:24:24,009 [mule.app.deployer.monitor.1.thread.1] org.mule.module.launcher.muledeploymentservice: ================== new exploded application: mulejmxenabler info 2014-08-24 16:24:24,010 [mule.app.deployer.monitor.1.thread.1] org.mule.module.launcher.application.defaultmuleapplication: ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ + new app 'mulejmxenabler' + ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ info 2014-08-24 16:24:24,668 [mule.app.deployer.monitor.1.thread.1] org.mule.module.launcher.muledeploymentservice: ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ + started app 'mulejmxenabler' + ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ the above is the minimum configuration that i need to enable remote jmx access to a mule instance. try connect to the mule instance using some jmx monitoring application, like jvisualvm or java mission control . the following steps describe how to do when using java mission control: launch java mission control. right-click in the jvm browser pane and select new connection. in the host field, enter the ip address or dns name that you used earlier in the mule-config.xml file. in my case that will be “192.168.1.73”. in the port field, enter the port number that you also entered in the mule-config.xml file earlier. in my case it was “1096”. click the test connection button. the status should be reported as ok as in this picture. click the finish button. you are now ready to connect to the mbean server of the mule instance and start monitoring it. this approach has the advantage of allowing modifications to the jmx configuration of a mule instance without having to restart it. if i want to make any modifications to the jmx configuration, enable or disable jmx in the mule instance i just edit the mule-config.xml file in the apps/mulejmxenabler directory in the mule instance home and save it. if hot deployment has not been disabled, the mule server will automatically re-deploy the application and pick up the changes. enabling jmx for a mule instance using wrapper parameters one alternative for enabling jmx monitoring of a mule instance that i have had success with is to add a set of java vm parameters in the wrapper configuration file of the mule instance. the wrapper configuration file is named “wrapper.conf” and can be found in the conf directory of the mule instance. to enable remote jmx access, add the following additional jvm parameters to your wrapper.conf file: # enables remote jmx management without authentication or ssl over port 1096. wrapper.java.additional.4=-dcom.sun.management.jmxremote wrapper.java.additional.5=-dcom.sun.management.jmxremote.port=1096 wrapper.java.additional.6=-dcom.sun.management.jmxremote.authenticate=false wrapper.java.additional.7=-dcom.sun.management.jmxremote.ssl=false wrapper.java.additional.8=-djava.rmi.server.hostname=192.168.1.73 important notes! you must adjust the numbering of the additional jmv parameters, as described in the comments in the wrapper.conf file! thus 4, 5, 6, 7 and 8 may not be the correct numbers for your wrapper.conf file. you must change the ip address to the remote ip address of the computer on which the mule server is running. you may want to change the port number. the mule instance must be restarted after the modifications, in order for them to come into effect. the drawback with this approach is that the mule instance needs to be restarted each time there is a modification to the jmx-related configuration parameters. with the target computer running mac os x, i need to chose one of the two described ways to enable remote jmx monitoring – if i use wrapper parameters, the mulejmxenabler application will not start properly. on ubuntu i can chose either of the two approaches but was also able to use both approaches simultaneously without errors. enabling the mx4j web interface if you are using the first approach, enabling jmx using a mule application, then adding the following xml element to the mule-config.xml file as a child element of the element enables the mx4j web interface exposing the jmx beans of the mule instance in question: as before, the ip address needs to be changed to the external ip address of the computer on which the mule instance is run. the port number may be changed from 1100 to any free port that you rather use. the mx4j web interface may, in my case, then be accessed using the url http://192.168.1.73:1100. install the jolokia mule agent with the first approach to enable jmx in a mule instance described above, you can also enable jolokia – the jmx-to-http bridge which enables use of the hawtio – an extensible web-based management console for java applications. note! version 1.2.2 of the jolokia mule agent, which at the time of writing is the latest, does not work with mule 3.5 due to the jetty libraries having been updated from version 6 to version 8. in this example i used mule 3.4, which is the latest version of mule that still use the jetty 6 libraries, as far as i know. download the jolokia mule agent from http://www.jolokia.org/download.html move the agent jar file to the lib/opt directory in the mule instance that you want to monitor. add the following configuration as a child element of the element in the mule-config.xml of the mulejmxenabler application created earlier: the port number may be modified as desired. open the url http://192.168.1.73:1095/jolokia/ in a web browser. note that you have to modify the ip address to the remote ip address of the computer running the mule instance and the port to the port number entered in the configuration earlier. if the jolokia agent was successfully enabled, you should see something like this in your web browser: {"timestamp":1408898064,"status":200,"request":{"type":"version"},"value":{"protocol":"7.2","config":{"maxdepth":"5","maxobjects":"10000","historymaxentries":"10","agentid":"192.168.1.73-1277-41c62ae4-mule","agenttype":"servlet","debug":"false","debugmaxentries":"100"},"agent":"1.2.2","info":{"product":"jetty","vendor":"mortbay","version":"6.1.26"}} with the jolokia agent in place, we can now monitor the mule instance using hawtio: download the hawtio jar from http://hawt.io/getstarted/index.html launch hawtio using the command “java -jar hawtio-app-1.4.17.jar” (the name of the jar file needs to match that of the file you downloaded earlier). hawtio should open a web browser and display a welcome page. if not, try the url http://localhost:8080/hawtio/welcome click the connect button in the upper left corner of the hawtio webpage. click the remote button. on the right, enter the remote ip of the computer on which your mule instance is running in the host field. 192.168.1.73 in my case. enter the port, 1095 in my case, from the configuration file in the port field. make sure the use proxy checkbox is checked. click the connect to remote server button. a new window or tab should open in your web browser. click the dashboard button in the upper left corner. you should now see information about the target computer, such as cpu and memory usage. click the jmx button next to the dashboard button. here you find the regular jmx management features. click the threads button next to the jmx button. this tab shows information about the different threads running in the target jvm. final words there are more things to tweak, but i hope that this will get you started with remote jmx monitoring of a mule instance. from there you can start modifying the parameters, adding security etc according to your requirements. more information on mule jmx management can be found here: http://www.mulesoft.org/documentation/display/current/jmx+management the oracle webpage on jmx technology can be found here: http://www.oracle.com/technetwork/java/javase/tech/javamanagement-140525.html finally, the oracle jmx tutorial can be found here: http://docs.oracle.com/javase/tutorial/jmx/
August 26, 2014
by Ivan K
· 18,601 Views · 1 Like
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From Personas to User Stories
1 Start with Personas The first step towards writing the right user stories is to understand your target users and customers. After all, user stories want to tell a story about the users using the product. If you don’t know who the users are and what problem we want to solve then it’s impossible to write the right stories and you end up with a long wish list rather than a description of the relevant product functionality. Personas offer a great way to capture the users and the customers with their needs. They are fictional characters that have a name and picture; relevant characteristics such as a role, activities, behaviours, and attitudes; and a goal, which is the problem that has to be addressed or the benefit that should be provided. Let’s look at an example. Say we want to create a game for children, which is fun to play and which educates the kids about music and dancing. We would then create at least two personas, one to represent the children, and one for the parents, as the following picture illustrates. The two sample personas above use my simple yet effective persona template. It encourages you to keep your personas concise, to focus on what really matters and to leave out the rest. You can download the template from romanpichler.com/tools/persona-template where more information on writing personas and using the template is available. Once you have created a cast of characters, select a primary persona, the persona you are mainly designing and building the product for. This helps you make the right product decision and get the user experience (UX) right. In the example above, I have chosen Yasmin as the primary persona. 2 Derive Epics from the Persona Goals Once you have created your personas, use their goals personas to identify the product functionality. Ask yourself what the product should do to address the personas’ problems or to create the desired benefits for them, as the following picture shows. Start with your primary persona and capture the functionality as epics, as coarse-grained, high-level stories. Write all the epics necessary to meet the persona goals but keep them rough and sketchy at this stage. For the dance game, we could write the epics below assuming that the game will be initially launched as an iPad app: As the epics above show, the game should allow the players to select different characters, to make them dance, to choose different dance floors and music tracks, to play the game with their friends, and to post a snapshot of their game on Facebook. While epics are great to sketch the product’s functionality, there is more to your product than epics and stories: You should also capture the user interaction and the sequences in which the epics are used, the visual design of your product, and the important nonfunctional qualities such as interoperability and performance. Use, for instance, workflow diagrams, story maps, storyboards, sketches, mock-ups, and constraint cards to describe them. You can find out more about describing the different product aspects in my post “User Stories are Not Enough to Create a Great User Experience”. 3 Progressively Decompose the Epics into User Stories With a holistic but coarse-grained description of your product in place start progressively decomposing your epics. Rather than detailing all epics and writing all user stories in one go, you derive your stories step by step as the following picture shows. As long as there are some significant risks present and you are figuring out what the product should look like and do, it’s best to derive just enough user stories just in time for the next sprint. Use your sprint goal or hypothesis to determine which epics to decompose and which stories to write as the following diagram illustrates. The approach depicted above minimises the amount of detailed items in your product backlog. This makes it easier to integrate new insights derived from exposing product increments or minimum viable products (MVPs) to users and customers. Say that we want to address the risk of creating the wrong game characters by developing an executable prototype that allows us to run a usability test with selected children. We could then write the following user stories: The stories above are derived from the epics “Choose character” and “Play with character”. The resulting prototype only partially implements the two epics – just to the extent of being able to test if the characters resonate with the users. Once you understand better how to meet the customer and user needs, you can start pre-writing user stories and have a larger inventory of detailed items on your product backlog as you are unlikely to experience bigger changes to your epics and your overall backlog. 4 Get the Stories Ready Before the development team starts working on the stories, check that each user story is ready: clear, feasible, and testable. A story is clear if there is a shared understanding between the product owner and the team about its meaning. It is feasible if it can be delivered in the next sprint according to the Definition of Done. This implies that the story is small enough to fit into the sprint but also that the necessary user interface design, test, and documentation work can be carried out. In the case of the sample stories above, we would have to add acceptance criteria, ensure that the stories are small enough to fit into the next sprint, and consider creating some very rough design sketches to indicate what the characters look like. For instance, to get the story “Yas chooses the little girl” ready, we could create the following rough sketch: The sketch above complement the user story and allows the team to implement the entire story including the visual design in the next sprint. With ready user stories in place the development team is in a good position to progress your product in an effective manner. For more details on getting user stories ready please take a look at my post “The Definition of Ready in Scrum”. Learn More You can learn more about writing the right epics and user stories by attending my Writing Great User Stories training course. If you want to learn more about the creating the UX artefacts mentioned in this post, then attend my Agile UX and Scrum training course. Please contact me if you are interested in having the courses delivered at your office. The persona pictures and the Manga girl sketch were created by Ole Størksen. Thanks Ole!
August 18, 2014
by Roman Pichler
· 15,436 Views · 5 Likes
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The Basics of Test-Driven Development
The objectives of Test Driven Development and unit testing are generally misunderstood. The problem is the word ‘test’, it is much less about testing and much more about specification of requirements, showing your working – as in maths, and the impact it has on design. TDD is much more important than only testing. Robert C Martin has a good analogy, he likens TDD to double entry bookkeeping: Software is a remarkably sensitive discipline. If you reach into a base of code and you change one bit you can crash the software. Go into the memory and twiddle one bit at random and very likely you will elicit some form of crash. Very, very few systems are that sensitive. You could go out to one of these bridges over here, start taking bolts out and they probably wouldn’t fall. I could pull out a gun and start shooting randomly and I probably wouldn’t kill too many people. I might wound a few but — you know — you get a bullet in the leg or a lung and you’d probably survive. People are resilient — they can survive the loss of a leg and so forth. Bridges are resilient — they survive the loss of components. But software isn’t resilient at all: one bit changes and — BANG! — it crashes. Very few disciplines are that sensitive. But there is one other [discipline] that is, and that’s Accounting. The right mistake at exactly the right time on the right spreadsheet — that one-digit error can crash the company and send the offenders off to jail. How do accountants deal with that sensitivity? Well, they have disciplines. And one of the primary disciplines is dual-entry bookkeeping. Everything is said twice. Every transaction is entered two times — once on the credit side and once on the debit side. Those two transactions follow separate mathematical pathways until they end up at this wonderful subtraction on the balance sheet that has to yield to zero. This is what test-driven development is: dual-entry bookkeeping. Everything is said twice — once on the test side and once on the production code side and everything runs in an execution that yields either a green bar or a red bar just like the zero on the balance sheet. It seems like that’s a good practice for us: to manage these sensitivities of our discipline… -Robert C. Martin The sensitivity of software is a good point to reflect upon, there is little in human experience that is so complex and yet so fragile. Without a strong focus on showing your working, no matter how good you are as a developer, if you omit the tests., your software will be worse than it could have been. The double-entry bookkeeping analogy only holds up though if you do test first development. If you write your test after the code it is generally not sufficiently independent to provide a valid “separate path” check. Test first is the idea that your write the test before you write the code that is being tested. This seems like a bizarre idea to many people at first, but actually makes perfect sense. If you write the test first and run it, you get to see it fail, so you are testing the test. If you write the test first then you are expressing what you want of your software from the outside in. It leads you to design for behaviour and so you have less of a tendency to get lost in irrelevant technicalities. This is a much more effective design approach than testing after you have written the code, and as a by product it leads inevitably to software that is easy to test – you have to be pretty dumb to write a test before you have written the code for an idea that can’t be tested! Finally there is a virtuous circle here. Software is easy to test when it is modular. It is easy to test when dependencies are externalised and it is easy to test when there is a clear separation of concerns. Now the software industry is famous for change, but if there is any idea that has remained constant for, literally, decades it is that quality software is modular, has well defined dependencies and clear separation of concerns – sound familiar? This has been how computer science has defined quality since before I started, and that was a very long time ago! Using TDD as a practice makes you produce higher quality software, not because it is well tested (though that is a nice by-product) but because it improves the quality of your designs. Want more detail: http://c2.com/cgi/wiki?TestDrivenDevelopment http://www.agiledata.org/essays/tdd.html http://butunclebob.com/ArticleS.UncleBob.TheThreeRulesOfTdd http://unitmm.sourceforge.net/fibonacci_example.shtml http://clean-cpp.org/test-driven-development/ http://agile2007.agilealliance.org/downloads/presentations/TDD-Cpp-Agile2007-HandsOnTddInCpp.ppt_801.pdf http://www.growing-object-oriented-software.com/
August 13, 2014
by Dave Farley
· 15,562 Views · 1 Like
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Java Unit Testing Interview Questions
The article presents some of the frequently asked interview questions in relation with unit testing with Java code. Please suggest other questions tthat you came across and I shall include in the list below. What is unit testing? Which unit testing framework did you use? What are some of the common Java unit testing frameworks? Ans: Read the definition of Unit testing on Wikipedia page for unit testing. Simply speaking, unit testing is about testing a block of code in isolation. There are two popular unit testing framework in Java named as Junit, TestNG. In SDLC, When is the right time to start writing unit tests? Ans: Test-along if not test-driven; Writing unit tests towards end is not very effective. Test-along technique recommends developers to write the unit tests as they go with their development. With Junit 4, do we still need methods such as setUp and tearDown? Ans: No. This is taken care with help of @Before and @After annotations respectively What do following junit test annotations mean? Ans: Following is a list of frequently used JUnit 4 annotations:@Test (@Test identifies a test method) @Before (Ans: @Before method will execute before every JUnit4 test)@After (Ans: @After method will execute after every JUnit4 test)@BeforeClass (Ans: @BeforeClass method will be executed before JUnit test for a Class starts)@AfterClass (Ans: @AfterClass method will be executed after JUnit test for a Class is completed)@Ignore (@Ignore method will not be executed) How do one do exception handling unit tests using @Test annotation? Ans: @Test(expected={exception class}. For example: @Test(expected=IllegalArgumentException.class) Write a sample unit testing method for testing exception named as IndexOutOfBoundsException when working with ArrayList? @Test(expected=IndexOutOfBoundsException.class) public void outOfBounds() { new ArrayList
August 6, 2014
by Ajitesh Kumar
· 48,465 Views · 3 Likes
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Using the OpenXML SDK Productivity Tool to "decompile" Office Documents
Ode To Code - Easily Generate Microsoft Office Files From C# "... These days, Office files are no longer in a proprietary binary format, and are we can create the files directly without using COM automation. A .docx Word file, for example, is a collection of XML documents zipped into a single file. The official name of the format is Open XML. There is an SDK to help with reading and writing OpenXML, and a Productivity Tool that can generate C# code for a given file. All you need to do is load a document, presentation, or workbook into the tool and press the “Reflect Code” button. The downside to this tool is that even a simple document will generate 4,000 lines of code. Another downside is that the generated code assumes it will write directly to the file system, however it is easy to pass in an abstract Stream object instead. So while this code isn’t perfect, the code does produce valid document and..." I've been blogging about the OpenXML SDK for years now, but I think this is the first time I've seen this part of it, this utility. And like he says, 4K LoC is like, well, allot, it does look like an awesome way to learn the low level OpenXML SDK ins and outs. Related Past Post XRef: Open Sesame - Open XML SDK is now open source Using OpenXML to load an Excel Worksheet into a DataTable (or just how different OpenXML is from the old Excel API we're used too) Using OpenXML SDK to generate Word documents via templates (and without Word being installed) Checking for Microsoft Word DocX/DocM Revisions/Track Changes without using Word... (via OpenXML SDK, LINQ to XML or XML DOM) LINQ to XlsX... Using VB.Net, LINQ, the OpenXML SDK and a little C# helper, to query an Excel XlsX Using native OpenXML to create an XlsX (Which provides an example of why I highlight tools that make OpenXML easier...) Generating Xlsx's on the Server? You're using OpenXML, right? With help from the PowerTools for OpenXML? Official boat-load, as in supertanker, sized OpenXML content list (Insert "One OpenXML content list to rule them all" here) So how do I get from here to OpenXML? Got a map for you, an Open XML SDK Blog Map… Where to go to scratch your OpenXML dev info itch… "Open XML Explained" Free eBook (PDF) The Noob's Guide to Open XML Dev (If you know how to spell OpenXML but that's about it, this is your Getting Started guide...) Reusing the PowerShell PowerTools for Open XML in your C# or VB.Net world PowerShell, OpenXML, WMI and the PowerTools for OpenXML = Doc generation for our inner geek Because it’s a PowerShell kind of day… PowerTools for Open XML V1.1 Released OpenXML PowerTools updated – Cell your Excel via PowerShell Powering into OpenXML with PowerShell Open XML SDK 2.0 for Microsoft Office Released – Automate Office documents without Office Open XML 2.0 Code Snippets for VS2010 (and VS2008 too) Open XML Format SDK 2.0 Code Snippets for Visual Studio 2008 – 52 C#/VB Code Snippets to help ease your Open XML coding Open XML File Format Code Snippets for Visual Studio 2005 (Office 2007 NOT required) Open XML SDK v1 Released OpenXML Viewer 1.0 Released – Open source DocX to HTML conversion, with IE, Firefox and Opera (and/or command line) support
July 31, 2014
by Greg Duncan
· 16,601 Views
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10 Tips for Creating an Agile Product Strategy with the Vision Board
1 Start with What You Know Now Traditionally, a product strategy is the result of months of market research and business analysis work. It is intended to be factual, reliable, and ready to be implemented. But in an agile, dynamic environment a product strategy is best created differently: Start with your idea, state the vision behind it, and capture your initial strategy. Then identify the biggest risk or the crucial leap-of-faith assumption, address it, and change and improve your strategy. Repeat this process until you are confident that your product strategy is valid. This iterative approach, piloted by Lean Startup, helps you acquire the new knowledge fast and in a goal-oriented, focused manner addressing the key risks or assumptions. It avoids the danger of carrying out too much and too little research, reduces time-to-market, and increases your chances of creating a successful product. 2 Focus on what Matters Most The term product strategy means different things to different people, and strategies come in different shapes and sizes. While that’s perfectly fine, an initial product strategy that forms the basis for subsequent correction and refinement cycles should focus on what matters most: the market, the value proposition, the product’s unique selling points, and the business goals. This is where my Vision Board comes in. I have designed it as the simplest thing that could possibly work to capture the vision and the product strategy. You can download it from romanpichler.com/tools/vision-board for free. For an introduction to the Vision Board, please see my post “The Product Vision Board”. 3 Create the Product Strategy Collaboratively A great way to create your product strategy is to employ a collaborative workshop. Invite the key people required to develop, market, sell and service your product and the senior management sponsor. Such a workshop generates early buy-in, creates shared ownership, and leverages the collective knowledge and creativity of the group. Selling an existing vision and product strategy can be challenging. Co-creation is often the better option. Your initial Vision Board has to be good enough to create a shared understanding of your vision and initial strategy and to identify the biggest risk so you can start re-working your board. But don’t spend too much time on it and don’t try to make it perfect. Your board will change as you correct, improve and refine it. 4 Let your Vision Guide you The product vision is the very reason for creating your product: It describes your overarching goal. The vision also forms the basis of your product strategy as the path to reach your overall goal. As the vision is so important, you should capture it before you describe your strategy. Here are four tips to help you capture your vision: Make sure that your vision does not restate your product idea but goes beyond it. For instance, the idea for this post is to write about creating an agile product strategy, but my vision is to help you develop awesome and successful products. Choose a broad vision, a vision that engages people and that enables you to pivot – to change the strategy while staying true to your vision. Make your vision statement concise; capture it in one or two sentences; and ensure that it is clear and easy to understand. Try to come up with a motivating and inspiring vision that helps unite everyone working on the product. Choosing an altruistic vision, a vision that focuses on the benefits created for others, can help you with this. 5 Put the Users First Once you have captured your vision, work on your strategy by filling in the lower sections of the Vision Board from left to right. Start with the “Target Group”, the people who should use and buy your product rather than thinking about the cool, amazing product features or the smart business model that will monetise the product. While both aspects are important, capturing the users and customers and their needs forms the basis for making the right product and business model decisions. While it’s tempting to think of all the people who could possibly benefit from your product, it is more helpful to choose a clear-cut and narrow target group instead. Describe the users and customers as clearly as you can and state the relevant demographic characteristics. If there are several segments that your product could serve then choose the most promising one. Working with a focused target group makes it easier to test your assumptions, to select the right test group and test method, and to analyse the resulting feedback and data. If it turns out that you have picked the wrong group or made the segment is too small then simply pivot to a new or bigger one. A large or heterogeneous target group is usually difficult to test. What’s more, it leads to many diverse needs, which make it difficult to determine a clear and convincing value proposition and therefore to market and sell the product. 6 Clearly State the Main Problem or Benefit Once you have captured your target users and customers, describe their needs. Consider why they would purchase and use your product. What problem will your product solve, what pain or discomfort will it remove, what tangible benefit will it create? If you identify several needs, then determine the main problem or the main benefit, for instance, by putting it at the top of the section. This helps you test your ideas and create a convincing value proposition. I find that if I am not able to clearly describe the main problem or benefit, I don’t really understand why people would want to use and to buy a product. 7 Describe the Essence of your Product Once you have captured the needs, use the “Product” section to describe your actual product idea. State the three to five key features of your product, those features that make the product desirable and that set it apart from its competitors. When capturing the features consider not only product functionality but also nonfunctional qualities such as performance and interoperability, and the visual design. Don’t make the mistake of turning this section into a product backlog. The point is not to describe the product comprehensively or in a great amount of detail but to identify those features that really matter to the target group. 8 State your Business Goals and Key Business Model Elements Use the “Value” section to state your business goals such as creating a new revenue stream, entering a new market, meeting a profitability goal, reducing cost, developing the brand, or selling another product. Make explicit why it is worthwhile for your company to invest in the product. Prioritise the business goals and state them in the order of their importance. This will guide your efforts and help you choose the right business model. Once you have captured the business goals, state the key elements of your business model including the main revenue sources and cost factors. This is particularly important when you work with a new or significantly changed business model. 9 Extend your Board The Vision Board’s simplicity is one of its assets, but it can sometimes become restricting: The Product and the Value sections can get crowded as the board does not separately capture the competitors, the partners, the channels, the revenue sources, the cost factors, and other business model elements. Luckily there is a simple solution: Extend your board and add further sections, for instance, “Competitors”, “Channels”, “Revenue Streams”, and “Cost Factors”, or download an extended version from my website. But before using an extended Vision Board make sure that you understand who your customers and users are and why they would buy and use the product. There is no point in worrying about the marketing and the sales channels or the technologies if you are not confident that you have identified a problem that’s worthwhile addressing. Additionally, a more complex board usually contains more risks and assumptions. This makes it harder to identify the biggest risk and leap-of-faith assumption. 10 Put it to the Test Capturing your vision and initial product strategy on the Vision Board is great. But it’s only the beginning of a journey in search of a valid strategy, as your initial board is likely to be wrong. After all, you have based the board on what you know now rather than extensive market research work. You should therefore review your initial Vision Board carefully, identify its critical risks or leap-of-faith assumptions, and select the most crucial risk or assumption. Determine the right test group, for instance, selected target users, and the right test method such as problem interviews. Carry out the test, analyse the feedback or data collected, and change your Vision Board with the newly gained knowledge as the picture below shows. If you find that the key risks and assumptions hard to identify then your board may be too vague. If that’s the case then narrow down the target group, select the main problem or benefit, reduce the key features to no more than five, identify the main business benefit, and remove everything else. Your board may significantly change as you iterate over your strategy, and you may have to pivot, to choose a different strategy to make your vision come true. If your Vision Board does not change at all then you should stop and reflect: Are you addressing the right risks in the right way and are you analysing the feedback and data effectively?
July 17, 2014
by Roman Pichler
· 8,996 Views
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On Collective Ownership and Responsibilities
Recently I’ve been butting heads with some people on the subject of Ownership, Responsibility and Accountability. There seems to be a very unhealthy obsession with these things sometimes, and I think this is indicative of a less-than-ideal culture. I don’t want to say that they’re “anti-agile” because that just sounds a bit weak, and because I also think they’re not just bad for agile, they’re bad for pretty much any system. I’m not sure how familiar most people are with the “RACI matrix” concept, but in my eyes it’s downright evil in the wrong hands, and I’ve been hearing “RACI Matrix” a lot recently (it’s now on my Bullshit Bingo card). I’ll start off by clarifying what I mean. I’ve got nothing against people owning actions or being accountable for certain particular (usually small) things, but I do take offence when pretty much everything has to be given an owner, someone accountable and someone to “take responsibility”. It’s divisive and results in lots of finger pointing, in my experience. I much prefer the concept of shared ownership, and collective accountability. As a software delivery team, we should all feel responsible for the quality of the product, as well as the performance and the feature richness. These things shouldn’t be assigned for ownership to individuals, as it’ll create an attitude of “well it’s not my problem” among the other team members. Here’s an example: I’ve worked in a team where one person was made the “owner” of the build system. They busied themselves making sure all the builds passed and that the system was regularly ticking over. Of course, the builds often failed and nobody cared except this one person, who then had to try to get people to fix their broken builds. It almost seemed as if people didn’t care about the fact that their software wasn’t capable of being compiled, or that the tests were failing, and in truth they didn’t. They cared about writing code and checking it in, because they didn’t “own” the build system. One message that I always try to drive home with software delivery teams is that our objective is to make software that works for our users, not just write code. I know how easy it is for developers to just focus on checking in code, or perhaps just make sure it passes the tests in the CI system, but beyond that, their focus drops off. I know because I was once one of those developers :-) These days I try to encourage everyone to care about things such as: How your code builds How the tests execute How good the tests are How good the code is How easy it is to deploy How easy it is to maintain How easy it is to monitor Because it takes all of these things to produce good software that users can enjoy, which means we get paid. Here’s another example of how “ownership” has hurt a product: A large system I once worked on was deployed into production using a complicated system of bash and perl scripts, which were cobbled together by a sysadmin who did the deployments. He became the de facto “owner” of the deployment system. There were untold issues with the running of the application because of permissions, paths etc and so forth. The deployment process was creaky and relatively untested. Since the “ownership” of this system was assigned to the sysadmin, rather than devolved or collectively shared throughout the delivery team, the “deployability” was seen as a second class citizen within the delivery team, because everybody felt like it was “owned” by one person who just happened to be on the periphery of the team at best. So here’s what I think: The ability to monitor, maintain, deploy, test, build and create software should all be treated as first class citizens and should be the collective responsibility of everyone in the team. They should all own it, and they should all be accountable. I would extend this out further, to include supporting systems such as environments, build systems, testing frameworks and so-on. Sure, each team might have an SME or two who focuses more on one of these things than any other, but that doesn’t make that one person accountable, responsible or the owner any more than any particular developer is the “owner” of any particular class, method or function. If I write some code that depends on a method that someone else has written, and that method is failing, I don’t just down tools, shrug my shoulders and say “well I’m not accountable for that”. That would be hugely unhelpful and I’d make no friends either. In the same way, we shouldn’t treat our supporting functions and systems as someone else’s responsibility. If we need it in order to make our software work for the end user, then it’s our collective responsibility, no matter what “it” is.
July 4, 2014
by James Betteley
· 9,588 Views
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Agile Assessments
This article was originally written by Sandi Keller for LeadingAgile. Assessments come in all forms and there are many reasons why we do them. In the end, we want to know something about the ability of someone or something. When working with a team or organization, an assessment can be introduced as a tool to assist in guiding an agile transformation and team improvement. For me as a coach, it’s an invaluable mechanism to communicate the transformation strategy and to measure progress. I love the simple approach taken in Elizabeth Hendrickson’s “Back-of-the-Napkin Agile Assessment Checklist” but sometimes we need something more extensive in an enterprise transformation setting, at least until our organization or team has reached a more mature state of agility. Over a series of posts, I’ll cover the why, what, when, and how of assessments and wrap it up with a post or two about how the data can be used once you’ve collected it. In this post, I’m going to talk about the Why and What of assessments. You will see at times that I refer to ‘assessment’ and at other times ‘self-assessment’. While the two are not completely interchangeable, I usually make the slight distinction that an assessment is scored by someone evaluating another group. Even for the self-assessment though, ideally there is an experienced guide facilitating the process until a team is more familiar with agile practices and capabilities. So why do an assessment anyway? Let’s consider some of the reasons you might be doing an assessment with a team or an organization: Baseline the current level agile adoption. Eventually you may think about measuring progress but take the time to baseline your abilities right from the start. See how you’re tracking against your adoption or transformation goals. Help sustain and grow your support. Determine if you’re ready to move to the next level of practice or adoption. Be honest, critical and brave! Recognize what has been mastered and what you are able to do with the new skill or capability. Change is tough so remember to celebrate your wins. Identify the next things you’re going to work on. Help the team narrow or target their focus. Set the context for organizational change. Use the assessment instrument as a change management tool. Make or support the case for needed coaching or training. Outside help can propel your progress. Sometimes an assessment or self-assessment may be for other reasons, such as creating a transformation roadmap or showing progress in order to secure continued funding. Even in these cases, I prefer to involve the team as much as possible so they can learn from the exercise and use the information derived from the assessment to target and make improvements. What sorts of things do we look at in an assessment? A team can be measured by improvement of a few practices or against more extensive measures that are part of a competency framework. A competency framework conceivably will focus on things we do, like Stand-ups, Iteration Planning or Retrospectives. It could also focus on capabilities such as Decomposing Features or Define Clear Acceptance Criteria. Or even against concepts like Whole Team or Open Workspace. Using a known competency framework can be useful to bring a level of consistent understanding across teams in the organization. It also facilitates alignment of good metrics as you plan and measure the finer nuance of implementing a particular practice or capability. The following section is a sample of assessment practices and capabilities along with a description for each. Roll Up Competency Practice or Capability Description Define the Product Identify Epics and Features Provide a clear definition of the product goals on the roadmap as feature and epic level deliverables valuable to the business. Produce visual specification around the Epic and Feature: personas, a feature flow chart, use case diagram, etc. Define Clear Acceptance Criteria Define what it takes for a product feature to be ready for use and the definition of done is clearly internalized by the team. Enterprise Alignment Demand Management Team is working from a single prioritized backlog, WIP is limited. Architectural Alignment Architecture aligned and actively involved in release planning. Architecture is actively working with teams to groom solutions Engineering Collective Code Ownership Developer can make code changes anywhere they need; developer can change code, fix bugs, refactor as necessary; few silos of knowledge. Continuous Integration Automated builds occur at every check in, tests pass locally before check in, immediate feedback when new code breaks the build. Plan & Coordinate Eliminate & Manage Risk Coordinate work across teams to limit impact of both internal and external risks to the team. Plan & Groom the Backlog Have enough work groomed ahead of the team so the team can do the work. Organization Enablement Empowered Teams People take ownership for their commitments and outcomes, within a defined set of organizational constraints. Develop Practice Competencies Do people have time to develop their craft? And do they put effort into it? Help the teams make appropriate decisions when applying the practices in their daily work. Communication Whole Team Team sits together, co-location of business/product owner, team is asset/product based, team has identity not based on project, product or department. Daily Stand-Up Occurs daily at same time, lasts 15 minutes or less, roadblocks surface and are visible, team selects stand-up time. The Roll Up Competency, or category, shown in the first column will bring perspective to your competency framework when you describe it to others and when you process the results. I’ll show a few analysis/reporting samples in my follow on post ‘Using the Data’. In my next post, I’ll talk about Rating Scales and Frequency, followed by Assessment Delivery Methods and finally, Using the Data you’ve collected, including use of the roll up categories. This article was originally written by Sandi Keller for LeadingAgile.
June 20, 2014
by Mike Cottmeyer
· 3,583 Views · 1 Like
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A Simple Cron Wrapper Script With Logging
When working with crontab service, one thing I often need is to capture the output of the job. Having the job script aware of this output and logging is tedious, and often make the script harder to read. So I wrote a shell wrapper that will redirect all job script's STDOUT into a log file. This way I can inspect it when a job has run and the job script can just focus on the task itself. # file: runcmd.sh # Helper/wrapper script to run any command in the crontab env. This script will ensure # user profile script is loaded and to log any command output into log files. It also # ensure not to print anything to STDOUT to avoid crontab system mail alert. # # NOTE: be sure to pass in absolute path of the command to be run so it can be found. # # Usage: # ./runcmd.sh find $HOME/crontab/test.sh # Simple use case # LOG_NAME=mytest ./runcmd.sh $HOME/crontab/test.sh # Change the log name to something specific # # Options DIR=`dirname $0` CMD="$@" CMD_NAME=`basename $1` LOG_NAME=${LOG_NAME:=$CMD_NAME} LOG="$DIR/logs/$LOG_NAME.log`date +%s`" # Ensure logs dir exists if [[ ! -e $DIR/logs ]]; then mkdir -p $DIR/logs fi # Run cron command source $HOME/.bash_profile echo "`date` Started cron cmd=$CMD, logname=$LOG_NAME" >> $LOG 2>&1 $CMD >> $LOG 2>&1 echo "`date` Cron cmd is done." >> $LOG 2>&1 With this wrapper, you can run any shell script and their output will be recorded. For example this job script below will clean up the logs accumulated in our logs folder. Note that the wrapper will also auto source the ".bash_profile". Often this this is needed if your job script expect all the env variables you already have setup in your login shell scripts. # file: remove-crontab-logs.sh DIR=`dirname $0`/logs echo "Checking and removing logs in $DIR" find $DIR -type f -mtime +31 -print -delete echo "Done" Now in the crontab file, you may run the job script like this: # Clean up crontab logs @montly $HOME/crontab/runcmd.sh $HOME/crontab/remove-crontab-logs.sh
June 9, 2014
by Zemian Deng
· 8,172 Views
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MapDB: The Agile Java Data Engine
MapDB is a pure Java database, specifically designed for the Java developer. The fundamental concept for MapDB is very clever yet natural to use: provide a reliable, full-featured and “tune-able” database engine using the Java Collections API. MapDB 1.0 has just been released, this is the culmination of years of research and development to get the project to this point. Jan Kotek, the primary developer for MapDB, also worked on predecessor projects (JDBM), starting MapDB as an entire from-scratch rewrite. Jan’s expertise and dedication to low-level debugging has yielded excellent results, producting an easy-to-use database for Java with comparable performance to many C-based engines. What sets MapDB apart is the “map” concept. The idea is to leverage the totally natural Java Collections API – so familiar to Java developers that most of them literally use it daily in their work. For most database interactions with a Java application, some sort of translator is required. There are many Object-Relational Mapping (ORM) tools to name just one category of such components. The goal has always been in the direction of making it natural to code in objects in the Java language, and translate them to a specific database syntax (such as SQL). However, such efforts have always come up short, adding complexity for both the application developer and the data architect. When using MapDB there is no object “translation layer” – developers just access data in familiar structures like Maps, Sets, Queues, etc. There is no change in syntax from typical Java coding, other than a brief initialization syntax and transaction management. A developer can literally transform memory-limited maps into a high-speed persistent store in seconds (typically changing just one line of code). A MapDB Example Here is a simple MapDB example, showing how easy and intuitive it is to use in a Java application: // Initialize a MapDB database DB db = DBMaker.newFileDB(new File("testdb")) .closeOnJvmShutdown() .make(); // Create a Map: Map myMap = db.getTreeMap(“testmap”); // Work with the Map using the normal Map API. myMap.put(“key1”, “value1”); myMap.put(“key2”, “value2”); String value = myMap.get(“key1”); ... That’s all you need to do, now you have a file-backed Map of virtually any size. Note the “builder-style” initialization syntax, enabling MapDB as the agile database choice for Java. There are many builder options that let you tune your database for the specific requirements at hand. Just a small subset of options include: In-memory implementation Enable transactions Configurable caching This means that you can configure your database just for what you need, effectively making MapDB serve the job of many other databases. MapDB comes with a set of powerful configuration options, and you can even extend the product to make your own data implementations if necessary. Another very powerful feature is that MapDB utilizes some of the advanced Java Collections variants, such as ConcurrentNavigableMap. With this type of Map you can go beyond simple key-value semantics, as it is also a sorted Map allowing you to access data in order, and find values near a key. Not many people are aware of this extension to the Collections API, but it is extremely powerful and allows you to do a lot with your MapDB database (I will cover more of these capabilities in a future article). The Agile Aspect of MapDB When I first met Jan and started talking with him about MapDB he said something that made a very important impression: If you know what data structure you want, MapDB allows you to tailor the structure and database characteristics to your exact application needs. In other words, the schema and ways you can structure your data is very flexible. The configuration of the physical data store is just as flexible, making a perfect combination for meeting almost any database need. They key to this capability is inherent in MapDB’s architecture, and how it translates to the MapDB API itself. Here is a simple diagram of the MapDB architecture: As you can see from the diagram, there are 3 tiers in MapDB: Collections API: This is the familiar Java Collections API that every Java developer uses for maintaining application state. It has a simple builder-style extension to allow you to control the exact characteristics of a given database (including its internal format or record structure). Engine: The Engine is the real key to MapDB, this is where the records for a database – including their internal structure, concurrency control, transactional semantics – are controlled. MapDB ships with several engines already, and it is straightforward to add your own Engine if needed for specialized data handling. Volume: This is the physical storage layer (e.g., on-disk or in-memory). MapDB has a few standard Volume implementations, and they should suffice for most projects. The main point is that the development API is completely distinct from the Engine implementation (the heart of MapDB), and both are separate from the actual physical storage layer. This offers a very agile approach, allowing developers to exactly control what type of internal structure is needed for a given database, and what the actual data structure looks like from the top-level Collections API. To make things even more extensible and agile, MapDB uses a concept of Engine Wrappers. An Engine Wrapper allows adding additional features and options on top of a specific engine layer. For example, if the standard Map engine is utilized for creating a B-Tree backed Map, it is feasible to enable (or disable) caching support. This caching feature is done through an Engine Wrapper, and that is what shows up in the builder-style API used to configure a given database. While a whole article could be written just about this, the point here is that this adds to MapDB’s inherent agile nature. By way of example, here is how you configure a pure in-memory database, without transactional capabilities: // Initialize an in-memory MapDB database // without transactions DB db = DBMaker.newMemoryDB() .transactionDisable() .closeOnJvmShutdown() .make(); // Create a Map: Map myMap = db.getTreeMap(“testmap”); // Work with the Map using the normal Map API. myMap.put(“key1”, “value1”); myMap.put(“key2”, “value2”); String value = myMap.get(“key1”); ... That’s it! All that was needed was to change the DBMaker call to add the new options, everything else works exactly the same as in the example shown earlier. Agile Data Model In addition to customizing the features and performance characteristics of a given database instance, MapDB allows you to create an agile data model, with a schema exactly matching your application requirements. This is probably similar to how you write your code when creating standard Java in-memory structures. For example, let’s say you need to lookup a Person object by username, or by personID. Simply create a Person object and two Maps to meet your needs: public class Person { private Integer personID; private String username; ... // Setters and getters go here ... } // Create a Map of Person by username. Map personByUsernameMap = ... // Create a Map of Person by personID. Map personByPersonIDMap = ... This is a very trivial example, but now you can easily write to both maps for each new Person instance, and subsequently retrieve a Person by either key. Another interesting concept with MapDB data structures are some key extensions to the normal Java Collections API. A common requirement in applications is to have a Map with a key/value, and in addition to finding the value for a key to be able to perform the inverse: lookup the key for a given value. We can easily do this using the MapDB extension for bi-directional maps: // Create a primary map HTreeMap map = DBMaker.newTempHashMap(); // Create the inverse mapping for primary map NavigableSet> inverseMapping = new TreeSet>(); // Bind the inverse mapping to primary map, so it is auto-updated each time the primary map gets a new key/value Bind.mapInverse(map, inverseMapping); map.put(10L,"value2"); map.put(1111L,"value"); map.put(1112L,"value"); map.put(11L,"val"); // Now find a key by a given value. Long keyValue = Fun.filter(inverseMapping.get(“value2”); MapDB supports many constructs for the interaction of Maps or other collections, allowing you to create a schema of related structures that can automatically be kept in sync. This avoids a lot of scanning of structures, makes coding fast and convenient, and can keep things very fast. Wrapping it up I have shown a very brief introduction on MapDB and how the product works. As you can see its strengths are its use of the natural Java Collections API, the agile nature of the engine itself, and the support for virtually any type of data model or schema that your application needs. MapDB is freely available for any use under the Apache 2.0 license. To learn more, check out: www.mapdb.org.
June 5, 2014
by Cory Isaacson
· 28,690 Views · 3 Likes
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Exploring Message Brokers: RabbitMQ, Kafka, ActiveMQ, and Kestrel
Explore different message brokers, and discover how these important web technologies impact a customer's backlog of messages, and cluster/data performance.
June 3, 2014
by Yves Trudeau
· 460,804 Views · 86 Likes
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New report looks at the role of Chambers of Commerce
The business world is an increasingly complex one. In the past few IBM CEO surveys, they have highlighted the growing importance of both being able to manage this complexity, and to do so in a collaborative way. This shifting zeitgeist was reflected in a series of seminars hosted by Xincus, and prompted the launch of a two phase study into how Chambers of Commerce can evolve within this new landscape. The study, consisting of in depth one on one interviews and a nationwide online survey, aimed to better understand both how Chambers can adapt, and what changes would be required to do so. The findings from this research are now available in a new paper called Chamber 2.0: Digital – Connected – Global. The paper outlines both the main challenges currently facing Chambers, and the steps they can take to thrive in such an environment. Amongst the main challenges identified by the research was a fundamental desire to change and modernize, with a strategic positioning and business model that would allow Chambers to flourish. There was also a strong desire to work more effectively with partners, both inside and outside of the Chamber network, sharing both resources and insights. The report then concluded with a road map derived by molding these findings from within the network with best practice from the wider business world. The road-map consists of five broad stages, with each one containing more detailed steps Chambers can take to prepare for the modern world. Become a one stop shop for members, including positioning the Chamber brand for the modern world as centers for Business, Innovation, and Economic Development with a new and modernized approach to business that sees an adaptive and responsive leadership style essential to a revitalize business model. Offer new value, with a new emphasis on virtual services to reflect modern ways of working. Chambers will become a solution hub that connects and match makes members, with co-working spaces connecting the physical and virtual worlds. Collaborate beyond borders, by building an extensive Chamber alliance network, allowing Chambers to become specialized regional hubs, whilst tapping into the collective wisdom of the entire network as well as offering “health-club” type e-memberships to professionals, academics, entrepreneurs and “free agent” millennials alike. Nurture new economic development, by facilitating entrepreneurial collaboration between members and stakeholders, connecting the right people with the right resources, helping to forge an innovation economy and a thriving business community and jobs. Foster global innovation ecosystems, by tying all of these communities together to form a hyperconnected ecosystem, with Chambers at its heart, thus empowering the next wave of new economic development around the world. The report makes clear that whilst change is desired, the network remains positive that the right developments will occur. With Chambers striving to maintain their position at the heart of the business community, this report will go some way towards helping them achieve that goal. You can get your copy of the report here. Original post
May 22, 2014
by Adi Gaskell
· 3,504 Views
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3 Reasons Why Knowledge Worker Engagement Is Decreasing
Due to the technological development with the Internet and social media, markets are no longer created and controlled with broadcast marketing. People can now find and connect with people like themselves all over the world – and no longer limited to the people in their close proximity and to existing ties such as family members, friends, colleagues or neighbors. They can connect with anyone, and they all influence each other, immediately and with multiplier effects. The power is shifting from companies to consumers. It is a radical shift, but it was predicted already in the mid 90’ies by marketing guru Philip Kotler as a consequence of the Internet. So we shouldn’t be too surprised. Yet a lot of companies are. And they haven’t prepared at all for this. Companies and organizations are waking up to a new reality, and the wake-up call can sometimes be harsh. A number of things are changing, and I will mention four of these here. 1. Change and uncertainty is the new normal To start with, today’s business environment is anything but static. It’s changing faster and faster, and in new ways. It’s becoming more and more unpredictable. This means that companies and organizations can’t do long-term planning like they used to. Instead they have to be prepared for change, to quickly adapt to new conditions and situations, such as changing consumer behaviors, new competition, new innovations, and so forth. 2. Diminishing return on optimization efforts The second big change is that the return on optimization efforts is diminishing. The companies that lead the development in their industries, and get all the profit are those that are able to create new value. They don’t do that with optimization. They do it by innovating new product and services, by creating and developing relationships with consumers and others, by collaborating internally and externally, and by constantly learning how change theirs strategies 3. Growth and efficiency is not enough Thirdly, being able to grow in terms of production volumes, market presence and market share is not enough to be successful, neither is it to produce and market products or services as efficiently as possible. Instead, continuous innovation and high responsiveness to change and customer demands is becoming more and more critical. This obviously can’t be addressed solely by streamlining and optimizing transactional processes, as we have done for the last few decades with the help of information technology. Innovation and responsiveness requires empowered people that can collaborate efficiently and effectively. That is why collaboration is the new productivity frontier. 4. Non-routine knowledge work is increasing in importance Finally, we can see that work is shifting from manual work to knowledge work, but most importantly from routine work to non-routine work. Computers and software are taking over repetitive and routine-based knowledge work, just as robots have replaced workers doing repetitive and routine manual work in the factories. The work that is remaining and increasing is the non-routine knowledge work that is often highly interdependent such as problem solving, product development, sales and so forth. Knowledge work is something completely different than most of the work that organizations have tried to improve and optimize during the 20th century. It’s fluid, dynamic, unpredictable, and non-repeatable. Knowledge workers need to look beyond the standard ways of doing things, to question information, rules, and ways of working. This is something completely different to how it is to work at a production line in a factory, where workers follow predefined and highly repeatable processes and procedure. Most organizations have been designed for efficiency and economies of scale, not for empowering people enabling collaboration, innovation and responsiveness. Too often, knowledge workers feel like they are just cogs in a big machinery. And unfortunately, in most cases, their feelings are motivated. We see all over that employees are increasingly dissatisfied with their jobs. Employee engagement is falling. It is especially bad in large and distributed organizations. The consequences are many and severe. Innovation is stifling. Productivity is, if not falling, not improving. People are leaving, or they want to leave, their jobs. It is hard to sustain and improve quality. And it’s not possible to recruit and retain talent by the quality and numbers that are needed. So what is causing this? I have grouped a number of causes into three overall themes; complexity, inflexibility, and disconnectedness. 1. Complexity As knowledge workers we often find ourselves stuck between a rock and a hard place. Workload and complexity at work is increasing, while we at the same time are expected to produce more, faster and faster. And adapt to new conditions. Not only that, we are expected to be creative and innovative as well. Still, if we look at an average day in the life of a knowledge worker, we struggle a lot with finding answers to basic questions, such as what is happening in our work environment, who is doing what, where I can fiend a piece of information, when it is my turn to contribute, and so on. This means that we spend a lot of time on things that are not creating value, just getting ready to create value. For example, Intel estimated that their employees spent one day per week on trying to find information and locating the expertise they needed to do their job. Although the tasks of knowledge workers come in all shapes and sizes, many of them rely on a number of basic capabilities, such as finding information or locating expertise. These capabilities are vital to knowledge worker productivity, but also to innovation, and it is evident that poor capabilities generate a lot of waste. Of course, we constantly get new tools that aim to help us. But when new tools and features are introduced to knowledge worker, there often is no guidance, and little customizing it to fit our needs. The problem is that we already have this huge pile of complex products to deal with, and we need to fit these. This technology-centric approach adds complexity instead of reducing it, instead of making things simpler for us. A study by Oracle found that productivity of enterprise application users had fallen almost 1/5 over a period of only three years. It’s like giving everybody Friday off. How can that be? I would argue that it’s the increasing complexity that is hampering productivity. 2. Inflexibility The second theme is inflexibility. By this I mean that our organizations and the systems that are there to help us get our work done are designed in a way that makes change, creativity and improvisation hard. Instead of empowering knowledge workers, our organizations often constrain and prevent us from being productive and innovative. First of all, there is a mismatch between what science knows and what organizations do when it comes to how they try to motivate knowledge workers to perform better. In most organizations, existing performance models are built on extrinsic motivators, or carrots and sticks if you like. These models worked pretty fine for routine, left-brain, rule-based work of 20th century, but they are not working very well for right-brained, creative, and self-propelled people performing non-routine and highly collaborative conceptual tasks. For example, bonuses and commissions don’t work for this kind of work. As a matter of fact, science shows they have the opposite effect than intended; the higher the extrinsic rewards, the worse the performance gets. Organizations are apparently making important decisions about their future based on the wrong assumptions. The left circle in this venn diagram represents things that have been considered important for trying to maximize the productivity of manual routine work. The right circle represents things that are important for motivating knowledge workers doing non-repetitive work. There is still little understanding and experience of how to do the things the right circle, so organizations and managers tend to stick with the things they know how to do. Those are the things in the left circle. Furthermore, knowledge workers need to have flexible working conditions. When it comes to knowledge work, work is not a place, it is something you do. Most knowledge worker tasks can be performed from any location, even those that require close collaboration with others. Organizations need to support this, not only to increase performance, but also to make people more engaged at work. Research shows that what employees of all age groups want is the flexibility to determine for themselves where, when, and how they work, and that increasing workplace flexibility has a positive effect on employee engagement and thereby also on employee productivity. A Virgin Media Business study found that 40% of the surveyed organizations often overhear employees complain about being tied to their desks and 7 in 10 organizations believe flexible working would make their employees both happier and more productive, boosting employee engagement. 3. Inconnectedness Finally, we have a theme that I call disconnectedness. It is about people and information being disconnected from each other, and thereby unable to share, cooperate and collaborate as is required to be productive and deal with the challenges organizations face. Collaborating isn’t as easy as it sometimes might sound, especially not in large and distributed organizations; there are too many barriers to collaborate naturally across an organization and across locations. In a complex and constantly changing work environment, it becomes even harder to find time and energy to overcome these barriers. It is only natural that we tend to share, cooperate and collaborate with people in our close proximity and that we already know and trust, failing to help and collaborate with others or share information that they might have use for. People work in silos. Silo thinking is a typical phenomenon in large organizations. Teams tend to focus on the parts they are responsible for and specialize in. They sub-optimize and focus on their own goals. They become organizational barriers that limit communication and impede sharing, collaboration, and innovation within the enterprise. Organizations have also created digital work environments to optimize personal productivity and teamwork, but doing so they have neglected the fact that knowledge work is increasingly relying on collaboration in networks across locations and organizations and stretching far beyond teams. It might seem as a paradox, but the modern and increasingly digital work environments have in fact made people more isolated and unaware of what is happening at work. This disconnectedness means that people become less engaged. And in a rapidly changing and complex work environment, this has serious implications, such as lost productivity and innovations. Or worse – talent is wasted and people leave. What do to about it? So what should organizations do to avoid the negative consequences of complexity, inflexibility and disconnectedness? The simple answer is that they should start working towards increased simplicity, flexibility and connectedness. What they should do and how, I will return to in my next post.
April 28, 2014
by Oscar Berg
· 3,426 Views
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The Programmer Productivity Paradox
Programmers seem to be fairly productive people. You always see them typing at their desks; they chafe for meetings to finish so that they can go back to their desks and code. When asked, they will say that there is not enough time to produce the code, and the sooner they can start coding, the sooner they will be done. So writing code must be the most important thing, correct? If the average programmer writes about 50 lines of production code a day. A 50,000 line program would take 1,000 man days to produce. The 50,000 line listing can be entered by a programmer at about 1,000 lines a day or about 50 man days. So what the heck are the developers doing for the other 950 days? Before addressing that issue, lets make a simple observation. Capers Jones has compared many methodologies (RUP, XP, Agile, Waterfall, etc) and programming languages over thousands of projects and determined that programmers write between 325 and 750 lines of code (LOC) per month, which is less than the 1,000 LOC per month suggested above 1. Even if programmers do not average 50 lines of code per day, the following is clear 2. Methodology does not explain the apparent productivity gap No language accounts for the apparent productivity gap The reality is that only a fraction of a developer's time is actually spent writing production code. If a developer is typing in code all the time then they are really trying different combinations of code until they finally find the combination of code that works. Or more correctly, the combination that seems to match the requirements until either QA or the business analyst comes back and lets them know there is a problem. That is why developers that plan their code before using the keyboard tend to outperform other developers. Not only do only a few developers really plan out their code before coding but also years of experience do not teach developers to learn to plan. In fact studies over 40 years show that developer productivity does not change with years of experience. (see No Experience Required!) Years of experience do not lead to higher productivity Interestingly enough, there are methodologies that have been around for a long time that emphasize planning code. Watts Humphrey is the creator of the Personal Software Process (PSP) 3. Using PSP has been measured to: PSP can raise productivity by 21.2% and quality by 31.2% If you are interested there are many other proven methods of raising code quality that are not commonly used (see Not Planning is for Losers). If your developers at their keyboard and not planning at a white board then odds are that your productivity is not as high as it could be. Bibliography 1 The The Mythical Man Month is even more pessimistic suggesting that programmers produce 10 production lines of code per day 2 Jones, Capers and Bonsignour, Olivier. The Economics of Software Quality. Addison Wesley. 2011 3 Watts, Humphrey. Introduction to the Personal Software Process, Addison Wesley Longman. 1997
March 17, 2014
by Dalip Mahal
· 111,845 Views · 24 Likes
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Setting Job Goals for Your Team: Senior Developer and Designer
If your employees aren't continuing to grow, your company will become stagnant. Here we examine goal-setting case study with the senior dev and the designer.
March 15, 2014
by Christina Popova
· 94,281 Views · 3 Likes
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Creating Complex Test Configurations with Red Deer
This is the second in a series of posts on the new “Red Deer” (https://github.com/jboss-reddeer/reddeer) open source testing framework for Eclipse. In the previous post in this series, we introduced Red Deer, learned how to install it into Eclipse, examined some of its cool features, and built and ran a sample test program from scratch. One of the challenges in creating effective automated tests is in making the tests self-sufficient enough to be able to set up their required operation environment, and robust enough to be able to determine whether that operating environment has been set up correctly. In the first post in this series, we took a quick look at Red Deer’s implementation of Requirements classes. In this post, we’ll take a more detailed look at Requirements, including how Red Deer supports your creating custom Requirements. The Case for Automated Test Requirements Let’s start by setting the context for why test programs need requirements. It’s often the case that a set of automated tests runs unattended and all the tests fail, not due to a bug in the software under test, but due to a broken or incomplete test environment. When we refer to a Red Deer “requirement,” we’re talking about actions that must be performed, or objects that must be created, before a test can be run. Examples of these requirements are having a user account defined or a connection to a database created and verified. What makes using Red Deer requirements different from your creating a less formal set of requirements with the @BeforeClass annotation provided by JUnit, is that if requirements are not met, then the test in question is not run. This can save you a lot of test execution time and test failure debugging time. Red Deer requirements are implemented in the RedDeerSuite. A test that makes use of requirements is must be run with a RedDeerSuite suite and annotated with @RunWith(RedDeerSuite.class) OOTB Red Deer Requirements As we saw in the first post in this series, Red Deer currently provides OOTB (out of the box) predefined requirements that enable you to clean out your current workspace and open a perspective. Using these requirements is simple. All you have to do is to add these import statements to your Red Deer test programs: import org.jboss.reddeer.eclipse.ui.perspectives.JavaBrowsingPerspective; import org.jboss.reddeer.requirements.cleanworkspace.CleanWorkspaceRequirement.CleanWorkspace; import org.jboss.reddeer.requirements.openperspective.OpenPerspectiveRequirement.OpenPerspective; And, we also have to add a reference to org.jboss.reddeer.requirements to the required bundle list in our example’s MANIFEST.MF file. And finally, add these annotations to the test program: @CleanWorkspace @OpenPerspective(JavaBrowsingPerspective.class) What if you want to define your own custom requirements? Let’s move on and examone how Red Deer supports that too. Different Ways to Implement New Red Deer Requirements Red Deer supports (4) ways to implement new requirements. We’ll look at them in order of their relative complexity: Simple Requirements Requirements with Parameters Requirements with Property Based Configuration Requirements with a Custom Schema In order to examine how Red Deer supports implementing new requirements, we’ll actually create some new requirements in Red Deer source code. In order to do this, we’ll have to download a copy of Red Deer’s source code. To perform this download, navigate to your desired directory and enter this command: git clone https://github.com/jboss-reddeer/reddeer.git And then, import Red Deer into eclipse as a set of existing Maven projects: If you navigate to the top level of the directory into which you downloaded the Red Deer source code, you’ll see this: What you want to do is to select all of the Red Deer projects. After you press the “Next>” key, Eclipse will import all the Red Deer packages as maven projects. (This may take a few minutes.) OK, now we can move on to creating some new requirements. We’ll start with the simplest of the (4) types, a simple requirement. Implementing a Simple Requirement A simple requirement consists of (2) parts: a “fulfilling” class that provides the code executed when the requirement is invoked, and an annotation that references that fulfilling class. As an illustration, let’s look at the skeleton “AdminUserRequirement” provided with your Red Deer download. This requirement is intended to serve as an example for implementing a full requirement to ensure that an admin-level user is defined before an attempt is made to run a test. The source file you want to look for is: /plugins/org.jboss.reddeer.examples/src/org/jboss/reddeer/junit/annotation/simple/AdminUserRequirement.java While it’s a small file, it’s a full example. It’s worthwhile examining it line-by-line: package org.jboss.reddeer.junit.annotation.simple; import java.lang.annotation.ElementType; import java.lang.annotation.Retention; import java.lang.annotation.RetentionPolicy; import java.lang.annotation.Target; import org.jboss.reddeer.junit.requirement.Requirement; import org.jboss.reddeer.junit.annotation.simple.AdminUserRequirement.AdminUser; /** * Admin user test requirement * @author lucia jelinkova * */ public class AdminUserRequirement implements Requirement { @Retention(RetentionPolicy.RUNTIME) @Target(ElementType.TYPE) public @interface AdminUser { } public boolean canFulfill() { // return true if you can connect to the database return true; } public void fulfill() { // create an admin user in the database if it does not exist yet } public void setDeclaration(AdminUser declaration) { // no need to access the annotation } } The important elements in this file are: Line 17 - @Retention - Specifies how the marked annotation is stored—Whether in code only, compiled into the class, or available at runtime through reflection. Line 18 - @Target - Marks another annotation to restrict the types of Java elements to which the the annotation can be applied Line 20 - AdminUser interface - This defines the object type used by the defined requirement. Line 23 - canFulfill method - In a fully written requirement this method will include the code to determine if the requirement can be met (or “fulfilled”). This method is set to always return a value of true. Line 32 - fulfill method - And here is the code that will be executed if the canFulfill method returns a value of true. For an example of the corresponding annotation in action, let’s look at the test program that is included with the fulfilling class. The test program is here: /plugins/org.jboss.reddeer.examples/src/org/jboss/reddeer/junit/annotation/simple/AdminUserTest.java This test program is also very short as it is a skeleton. The outline is there, but the specific logic that to implement the AdminUser requirement is left as an “exercise for the reader.” package org.jboss.reddeer.junit.annotation.simple; import org.jboss.reddeer.junit.runner.RedDeerSuite; import org.jboss.reddeer.junit.annotation.simple.AdminUserRequirement.AdminUser; import org.junit.Test; import org.junit.runner.RunWith; @RunWith(RedDeerSuite.class) @AdminUser /** * Test with AdminUser requirement * @author lucia jelinova * */ public class AdminUserTest { @Test public void test(){ // put test logic here } } The @AdminUser annotation on line NN tells the whole story. When this annotation is executed, the fulfilling class is invoked and if the “canFulfill()” method returns true, the test is executed. If the method returns false, then the test is not executed. Let’s run this test and see what happens. First, locate the AdminUserTest.java file in the eclipse Navigator view: Then, right-click and specify that it be executed as a JUnit test: And, not surprisingly, here’s the successful output from the test: Before we move on, let’s modify the canFulFill() method to return a false value, and rerun the test. The results look like this: 22:11:04.923 INFO [main][RequirementsRunnerBuilder] Found test class org.jboss.reddeer.junit.annotation.simple.AdminUserTest 22:11:04.924 INFO [main][RequirementsBuilder] Creating requirements for test class org.jboss.reddeer.junit.annotation.simple.AdminUserTest 22:11:04.925 DEBUG [main][RequirementsBuilder] Found requirement class org.jboss.reddeer.junit.annotation.simple.AdminUserRequirement for annotation interface org.jboss.reddeer.junit.annotation.simple.AdminUserRequirement$AdminUser 22:11:04.927 INFO [main][Requirements] Requirement class org.jboss.reddeer.junit.annotation.simple.AdminUserRequirement can be fulfilled: false 22:11:04.927 INFO [main][RequirementsRunnerBuilder] All requirements cannot be fulfilled, the test will NOT run So, this time, the requirement was not met and the test was not run. Note that the requirement did the work for us. We did not have to write a lot of new code to determine if the requirement had been met to decide whether or not to run the test. That’s all well and good for a simple requirement. But what about if we want to make the requirement a bit more flexible by enabling us to pass it a parameter? Let’s look at that next. Implementing a Requirement with Parameters In order to implement a requirement that accepts one or more parameters, we have to make two additions to the simple requirement that we just examined. First, we have to use a different requirement definition. The code that we want to look at this time is here: /plugins/org.jboss.reddeer.examples/src/org/jboss/reddeer/junit/annotation/advanced/UserRequirement.java The file looks like this: package org.jboss.reddeer.junit.annotation.advanced; import java.lang.annotation.ElementType; import java.lang.annotation.Retention; import java.lang.annotation.RetentionPolicy; import java.lang.annotation.Target; import org.jboss.reddeer.junit.requirement.Requirement; import org.jboss.reddeer.junit.annotation.advanced.UserRequirement.User; /** * Parameterized requirement with parameter name * @author vpakan * */ public class UserRequirement implements Requirement { @Retention(RetentionPolicy.RUNTIME) @Target(ElementType.TYPE) public @interface User { String name(); } private User user; public boolean canFulfill() { // return true if you can connect to the database return true; } public void fulfill() { System.out.println("Fulfilling reuirement User with name: " + user.name()); // create an admin user in the database if it does not exist yet } public void setDeclaration(User user) { this.user = user; } } The important difference between this class and the original AdminUserRequirement that we examined a moment ago is: Line 20 - The interface “User” now defines a String parameter “name” and on line NNN here the User object is defined. Second, we have to change the declaration of the requirement in the test program. The test program that we’ll look at this time is here: /plugins/org.jboss.reddeer.examples/src/org/jboss/reddeer/junit/annotation/advanced/UserTest.java Finally, our test program for this requirement looks like this: package org.jboss.reddeer.junit.annotation.advanced; import org.jboss.reddeer.junit.runner.RedDeerSuite; import org.jboss.reddeer.junit.annotation.advanced.UserRequirement.User; import org.junit.Test; import org.junit.runner.RunWith; @RunWith(RedDeerSuite.class) @User(name="admin") /** * Test with parameterized requirement User * @author lucia jelinkova * */ public class UserTest { @Test public void test(){ // put test logic here } } The interesting line in this test is: Line 8 - @User(name="admin") - Where we set the value of the “name” parameter. When we run the UserTest as a JUnit test, we see this output: 20:46:03.554 INFO [main][RequirementsRunnerBuilder] Found test class org.jboss.reddeer.junit.annotation.advanced.UserTest 20:46:03.555 INFO [main][RequirementsBuilder] Creating requirements for test class org.jboss.reddeer.junit.annotation.advanced.UserTest 20:46:03.556 DEBUG [main][RequirementsBuilder] Found requirement class org.jboss.reddeer.junit.annotation.advanced.UserRequirement for annotation interface org.jboss.reddeer.junit.annotation.advanced.UserRequirement$User 20:46:03.558 INFO [main][Requirements] Requirement class org.jboss.reddeer.junit.annotation.advanced.UserRequirement can be fulfilled: true 20:46:03.558 INFO [main][RequirementsRunnerBuilder] All requirements can be fulfilled, the test will run 20:46:03.575 INFO [main][RedDeerSuite] RedDeer suite created 20:46:03.584 INFO [main][Requirements] Fulfilling requirement of class org.jboss.reddeer.junit.annotation.advanced.UserRequirement Fulfilling requirement User with name: admin 20:46:03.585 DEBUG [main][RequirementsRunner] Injecting fulfilled requirements into test instance 20:46:03.587 INFO [main][RequirementsRunner] Started test: test(org.jboss.reddeer.junit.annotation.advanced.UserTest)20:46:03.588 INFO [main][RequirementsRunner] Finished test: test(org.jboss.reddeer.junit.annotation.advanced.UserTest) While it makes requirements more flexible when you are able to add parameters to their definition, it is still limited as a solution as you have to handle the individual parameters one by one. Fortunately, Red Deer also supports defining test configurations in your own custom XML schemas. Defining Complex Configurations - Two Approaches Red Deer supports two different approaches to defining complex configurations. You can either: Define the configuration as a set of (key=value) properties. If you choose this approach, you will have to also define setter methods for each property in your requirement’s fulfilling class. Create a custom XML schema. If you choose this approach, you will have to create a configuration object in your test code and then inject that object into your requirement. Regardless of which approach you choose, you store the configuration data in either a single XML file, or directory of XML files and then pass those files to your test program by defining this JVM argument when you run your test programs: -Dreddeer.config=/home/path/to/file/or/directory Let’s examine each of these approaches in detail. We’ll start with the properties based approach. Requirements with a Property Based Configuration The first thing we have to do to use a property based configuration is to define the properties. We’ll do this in an an XML file that complies with the Red Deer requirements XSD schema file. You can view the XSD here: http://cloud.github.com/downloads/jboss-reddeer/reddeer/RedDeerSchema.xsd The code for this example is here: /jboss/local/reddeer_fork/reddeer/plugins/org.jboss.reddeer.examples/src/org/jboss/reddeer/junit/configuration/simple And - here’s our properties file. Note that the requirement defined in this file contains two properties: name and ip (IP address). Let’s now expand on the “UserRequirement” example that we defined a few minutes ago. What we want to be able to do is to remove hardcoded requirements data from the source code and instead define that data in set of properties. To use this requirements.xml file, we have to make some changes to the UserRequirement.java class. package org.jboss.reddeer.junit.annotation.simple; import java.lang.annotation.ElementType; import java.lang.annotation.Retention; import java.lang.annotation.RetentionPolicy; import java.lang.annotation.Target; import org.jboss.reddeer.junit.requirement.Requirement; import org.jboss.reddeer.junit.annotation.simple.UserRequirement.User; import org.jboss.reddeer.junit.requirement.PropertyConfiguration; /** * Admin user test requirement * @author lucia jelinkova */ public class UserRequirement implements Requirement , PropertyConfiguration { @Retention(RetentionPolicy.RUNTIME) @Target(ElementType.TYPE) public @interface User { } private String name; private String ip; public boolean canFulfill() { // return true if you can connect to the database return true; } public void fulfill() { System.out.println("Fulfilling User requirement with\nName: " + name + "\nIP: " + ip); // create an admin user in the database if it does not exist yet } @Override public void setDeclaration(User user) { // annotation has no parameters no need to store reference to it } public void setName(String name) { this.name = name; } public void setIp(String ip) { this.ip = ip; } public String getName() { return name; } public String getIp() { return ip; } } The important changes are the addition of this import statement at line 8: import org.jboss.reddeer.junit.requirement.PropertyConfiguration And the addition of the implement clauses for the Requirement (with a type of User), and the PropertyConfiguration (so that the properties can be read) at line 15: public class UserRequirement implements Requirement , PropertyConfiguration And addition of the setter methods for the name and ip properties. Finally, here is the updated test program: package org.jboss.reddeer.junit.annotation.simple; import org.jboss.reddeer.junit.runner.RedDeerSuite; import org.jboss.reddeer.junit.annotation.simple.UserRequirement.User; import org.junit.Test; import org.junit.runner.RunWith; import org.jboss.reddeer.junit.requirement.inject.InjectRequirement; @RunWith(RedDeerSuite.class) @User /** * Test with AdminUser requirement * @author lucia jelinova * */ public class UserTest { @InjectRequirement private UserRequirement userRequirement; @Test public void test(){ System.out.println("The test is running"); System.out.println(userRequirement.getName()); // put test logic here } } What’s new in the test program is the addition of the import statement for the requirement injection: import org.jboss.reddeer.junit.requirement.inject.InjectRequirement; And the code to define and inject the UserRequirement: @InjectRequirement private UserRequirement userRequirement; When we run the test, we have to reference the configuration file via a Java VM argument . This means that we must define a new “run configuration” that is based on the JUnit run configuration provided in Eclipse and provide the VM argument that references the configuration file: In our example, the -Dreddeer.config VM argument is defined as: -Dreddeer.config=/jboss/local/reddeer_fork/reddeer/plugins/org.jboss.reddeer.examples/src/org/jboss/reddeer/junit/annotation/simple/reddeer.xml To execute the test, right-click on the UserTest class, and select the run configuration we just created: And, the test generates this test output in the console: 22:40:50.988 INFO [main][RedDeerSuite] Creating RedDeer suite... 22:40:50.990 INFO [main][SuiteConfiguration] Looking up configuration files defined via property reddeer.config=/jboss/local/reddeer_fork/reddeer/plugins/org.jboss.reddeer.examples/src/org/jboss/reddeer/junit/annotation/simple/reddeer.xml 22:40:50.991 INFO [main][SuiteConfiguration] Found configuration file /jboss/local/reddeer_fork/reddeer/plugins/org.jboss.reddeer.examples/src/org/jboss/reddeer/junit/annotation/simple/reddeer.xml 22:40:50.992 INFO [main][RedDeerSuite] Adding suite with name reddeer.xml to RedDeer suite 22:40:51.012 INFO [main][RequirementsRunnerBuilder] Found test class org.jboss.reddeer.junit.annotation.simple.UserTest 22:40:51.025 INFO [main][RequirementsBuilder] Creating requirements for test class org.jboss.reddeer.junit.annotation.simple.UserTest 22:40:51.027 DEBUG [main][RequirementsBuilder] Found requirement class org.jboss.reddeer.junit.annotation.simple.UserRequirement for annotation interface org.jboss.reddeer.junit.annotation.simple.UserRequirement$User 22:40:51.027 DEBUG [main][PropertyBasedConfigurator] Setting property based configuration to requirement class org.jboss.reddeer.junit.annotation.simple.UserRequirement 22:40:51.031 DEBUG [main][XMLReader] Reading configuration for class org.jboss.reddeer.junit.internal.configuration.entity.PropertyBasedConfiguration 22:40:51.827 DEBUG [main][PropertyBasedConfigurator] Configuration successfully set 22:40:51.828 INFO [main][Requirements] Requirement class org.jboss.reddeer.junit.annotation.simple.UserRequirement can be fulfilled: true 22:40:51.828 INFO [main][RequirementsRunnerBuilder] All requirements can be fulfilled, the test will run 22:40:51.865 INFO [main][RedDeerSuite] RedDeer suite created 22:40:51.874 INFO [main][Requirements] Fulfilling requirement of class org.jboss.reddeer.junit.annotation.simple.UserRequirement Fulfilling User requirement with Name: USERS_ADMINISTRATION IP: 127.0.0.1 22:40:51.875 DEBUG [main][RequirementsRunner] Injecting fulfilled requirements into test instance 22:40:51.876 INFO [main][RequirementsRunner] Started test: test reddeer.xml(org.jboss.reddeer.junit.annotation.simple.UserTest) 22:40:51.876 INFO [main][RequirementsRunner] Started test: test reddeer.xml(org.jboss.reddeer.junit.annotation.simple.UserTest) The test is running USERS_ADMINISTRATION 22:40:51.878 INFO [main][RequirementsRunner] Finished test: test reddeer.xml(org.jboss.reddeer.junit.annotation.simple.UserTest) 22:40:51.878 INFO [main][RequirementsRunner] Finished test: test reddeer.xml(org.jboss.reddeer.junit.annotation.simple.UserTest) Requirements with a Custom Schema The fourth and final approach to defining new requirements is to create a custom XML schema. This is the most complex approach, but it also provides you with the most flexibility as you can more easily share requirements in multiple configuration files. Also, this approach can protect you against forgetting to define properties in the configuration files by designating specific properties as required XML elements. To use this approach, you create a custom XML schema, then you create a configuration object in the test programs, and inject that object into your requirement. The configuration details are defined in an XML file and accessed through JAXB annotations. Let’s take a look at an example. The code for this example is available in Red Deer here: /plugins/org.jboss.reddeer.examples/src/org/jboss/reddeer/junit/configuration/advanced In order to use a custom XML schema, you need a custom schema. In this example, the schema is defined in a local file: /plugins/org.jboss.reddeer.examples/src/org/jboss/reddeer/junit/configuration/advanced/RedDeerRequirements.xsd This example schema is fairly simple, but it provides the flexibility needed for the example to define a test configuration of key=value pairs in the context of testruns and requirements. Also, the schema enforces the “required” setting for the requirement name. The configuration for requirement is defined in an XML requirement configuration file, the format of which complies with the custom schema: USERS_ADMINISTRATION 127.0.0.1 1111 In order to make use of this configuration, the Requirement class must instantiate a “UserConfiguration” object for the requirement. The UserRequirement class implements the org.jboss.reddeer.junit.requirement.CustomConfiguration interface with and specifies a type of UserConfiguration to enable the use of custom configurations: package org.jboss.reddeer.junit.configuration.advanced; import java.lang.annotation.ElementType; import java.lang.annotation.Retention; import java.lang.annotation.RetentionPolicy; import java.lang.annotation.Target; import org.jboss.reddeer.junit.requirement.CustomConfiguration; import org.jboss.reddeer.junit.requirement.Requirement; import org.jboss.reddeer.junit.configuration.advanced.UserRequirement.User; /** * User requirement using configuration from custom xml file * @author lucia jelinkova * */ public class UserRequirement implements Requirement, CustomConfiguration { @Retention(RetentionPolicy.RUNTIME) @Target(ElementType.TYPE) public @interface User { String name(); } private User user; private UserConfiguration userConfiguration; public boolean canFulfill() { // return true if you can connect to the database return true; } public void fulfill() { System.out.println("fulfiling requirement User with\nName: " + user.name() + "\nDB name: " + userConfiguration.getDbName() + "\nPort: " + userConfiguration.getPort() + "\nIP: " + userConfiguration.getIp()); // create an admin user in the database if it does not exist yet } public void setDeclaration(User user) { this.user = user; } public Class getConfigurationClass() { return UserConfiguration.class; } public void setConfiguration(UserConfiguration config) { this.userConfiguration = config; } } The UserConfiguration object (see line 25) is used by the org.jboss.reddeer.junit.requirement.CustomConfiguration class to provide the values for the requirement. The UserConfiguration definition (see below) maps the requirement as defined in the elements defined in the requirement XML file. package org.jboss.reddeer.junit.configuration.advanced; import javax.xml.bind.annotation.XmlElement; import javax.xml.bind.annotation.XmlRootElement; /** * Stores user requirement configuration loaded from custom xml file * @author lucia jelinkova * */ @XmlRootElement(name="user-requirement", namespace="http://www.jboss.org/NS/user-schema") public class UserConfiguration { private String dbName; private String ip; private String port; public String getIp() { return ip; } @XmlElement(namespace="http://www.jboss.org/NS/user-schema") public void setIp(String ip) { this.ip = ip; } public String getPort() { return port; } @XmlElement(namespace="http://www.jboss.org/NS/user-schema") public void setPort(String port) { this.port = port; } public String getDbName() { return dbName; } @XmlElement(name="db-name", namespace="http://www.jboss.org/NS/user-schema") public void setDbName(String dbName) { this.dbName = dbName; } } Note the getter and setter methods in the class definition. These methods make use of JAXB annotations to access the configuration element values. The test program looks largely the same as the test programs that we’ve used in the earlier examples. (It’s a nice characteristic of Red Deer tests in that since the “heavy lifting” is performed by the Red Deer harness, the tests can be kept simple, and therefore kept easy to maintain.) package org.jboss.reddeer.junit.configuration.advanced; import org.jboss.reddeer.junit.runner.RedDeerSuite; import org.jboss.reddeer.junit.configuration.advanced.UserRequirement.User; import org.junit.Test; import org.junit.runner.RunWith; /** * User test using configuration from custom xml file * Set VM parameter -Dreddeer.config to point to directory with requirements.xml file * -Dreddeer.config=${project_loc}/src/org/jboss/reddeer/junit/configuration/advanced * @author lucia jelinkova */ @RunWith(RedDeerSuite.class) @User(name="admin") public class UserTest { @Test public void test(){ // put your test logic here } } When the program is run, the console shows that the requirement was successfully met: 21:26:25.075 INFO [main][RedDeerSuite] Creating RedDeer suite... 21:26:25.077 INFO [main][SuiteConfiguration] Looking up configuration files defined via property reddeer.config=/jboss/local/reddeer_fork/reddeer/plugins/org.jboss.reddeer.examples/src/org/jboss/reddeer/junit/configuration/advanced/requirements.xml 21:26:25.077 INFO [main][SuiteConfiguration] Found configuration file /jboss/local/reddeer_fork/reddeer/plugins/org.jboss.reddeer.examples/src/org/jboss/reddeer/junit/configuration/advanced/requirements.xml 21:26:25.078 INFO [main][RedDeerSuite] Adding suite with name requirements.xml to RedDeer suite 21:26:25.084 INFO [main][RequirementsRunnerBuilder] Found test class org.jboss.reddeer.junit.configuration.advanced.UserTest 21:26:25.087 INFO [main][RequirementsBuilder] Creating requirements for test class org.jboss.reddeer.junit.configuration.advanced.UserTest 21:26:25.089 DEBUG [main][RequirementsBuilder] Found requirement class org.jboss.reddeer.junit.configuration.advanced.UserRequirement for annotation interface org.jboss.reddeer.junit.configuration.advanced.UserRequirement$User 21:26:25.089 DEBUG [main][CustomConfigurator] Setting custom configuration to requirement class org.jboss.reddeer.junit.configuration.advanced.UserRequirement 21:26:25.090 DEBUG [main][CustomConfigurator] Configuration object associated with requirement class org.jboss.reddeer.junit.configuration.advanced.UserRequirement is class org.jboss.reddeer.junit.configuration.advanced.UserConfiguration 21:26:25.090 DEBUG [main][XMLReader] Reading configuration for class org.jboss.reddeer.junit.configuration.advanced.UserConfiguration 21:26:25.782 DEBUG [main][CustomConfigurator] Configuration successfully set 21:26:25.832 INFO [main][Requirements] Requirement class org.jboss.reddeer.junit.configuration.advanced.UserRequirement can be fulfilled: true 21:26:25.832 INFO [main][RequirementsRunnerBuilder] All requirements can be fulfilled, the test will run 21:26:25.911 INFO [main][RedDeerSuite] RedDeer suite created 21:26:25.921 INFO [main][Requirements] Fulfilling requirement of class org.jboss.reddeer.junit.configuration.advanced.UserRequirement fulfiling requirement User with Name: admin DB name: USERS_ADMINISTRATION Port: 1111 IP: 127.0.0.1 21:26:25.922 DEBUG [main][RequirementsRunner] Injecting fulfilled requirements into test instance 21:26:25.923 INFO [main][RequirementsRunner] Started test: test requirements.xml(org.jboss.reddeer.junit.configuration.advanced.UserTest) 21:26:25.924 INFO [main][RequirementsRunner] Started test: test requirements.xml(org.jboss.reddeer.junit.configuration.advanced.UserTest) 21:26:25.925 INFO [main][RequirementsRunner] Finished test: test requirements.xml(org.jboss.reddeer.junit.configuration.advanced.UserTest) 21:26:25.925 INFO [main][RequirementsRunner] Finished test: test requirements.xml(org.jboss.reddeer.junit.configuration.advanced.UserTest) Before we move on, let’s try introducing an error in the XML test configuration and then see how Red Deer can trap that error. I don’t know about you, but avoiding typos is sometimes difficult for me. Let’s “inadvertently” remove the (required) name for the requirement. And rerun the test. This time, the console output shows: ERROR [main][XMLReader] cvc-complex-type.4: Attribute 'name' must appear on element 'user:user-requirement'. And the Junit output shows: org.jboss.reddeer.junit.configuration.RedDeerConfigurationException: Xml configuration is not valid. Recap In this post, we examined the (4) ways in which Red Deer supports creating your own custom test configurations. These methods range from simple requirements that optionally include parameters, to more complex requirements that can be defined in external XML files, either as key=value pairs or in a custom schema, that can be be shared between multiple test cases. It’s often the case that automated test runs can fail not because of bugs in software under test, but because the environment required by the test was properly initialized. Red Deer, by providing multiple approaches to create custom requirements helps you to ensure that your test failures can be more easily debugged and configuration errors are detected. What’s Next? In the next post in this series, we’ll take a look at how Red Deer makes creating new tests from scratch easier through its keystroke recorder feature. References https://github.com/jboss-reddeer/reddeer/wiki/Requirements http://www.oracle.com/technetwork/articles/javase/index-140168.html (JAXB)
March 14, 2014
by Len DiMaggio
· 7,291 Views
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