continuing from my previous post about azure service bus, in this post i will share my learning about queues & messages. the focus of this post will be about some of the undocumented things i found as we implemented support for queues and messages in cloud portam . queues as mentioned in my previous post, queues is the simplest of the azure service bus service and kind of compares with azure storage queue service in the sense that it provides a unidirectional messaging infrastructure where a publisher publishes a message and the message is received by a receiver. there can be many receivers ready to receive the messages however one receiver can only receive a message. no two receivers can receive a single message simultaneously. now some learning about queues. queue name a queue name can be up to 260 characters in length and can contain letters, numbers, periods (.), hyphens (-), and underscores (_) . a queue name is case-insensitive. queue size when creating a queue, you must define the size of the queue. queue size could be one of the following values: 1 gb, 2 gb, 3 gb, 4 gb or 5 gb . a queue size can’t be changed once the queue is created. however if you create a “ partition enabled queue ” then service bus creates 16 partitions thus your queue size is automatically multiplied by 16 and your queue size becomes 16 gb, 32 gb, 48 gb, 64 gb or 80 gb depending on the size you selected (this confused me initially :)). queue properties a service bus queue has many properties. some of the properties can only be set during queue creation time while some of the properties can only be set if you are using “standard” tier of service bus. (above are the screenshots from cloud portam for creating a queue) status indicates the status of a queue – active or disabled . once a queue is disabled, it cannot send or receive messages. max delivery count (maxdeliverycount) indicates the maximum number of times a message can be delivered . once this count has exceeded, message will either be removed from the queue or dead-lettered. the way i understand it is this property is used to manage poison messages. if a message is not processed successfully by receivers for “x” number of times, just move it somewhere else for further inspection or remove it. message time to live (messagettl) indicates a time span for which a message will live inside a queue . if the message is not processed by that time, it will either be removed or dead-lettered. one interesting thing i noticed is that if you’re using “standard” tier, a message could live forever in a queue however in “basic” tier, a message can only live for a maximum of 14 days . lock duration (lockduration) indicates number of seconds for which a message will be locked by a receiver once it receives it so that no other receiver can receive that message . it essentially gives the receiver time to process the message. once this elapses, message will be available to be received by another receiver. maximum value for lock duration can be 5 minutes / 300 seconds . enable partitioning (enablepartitioning) indicates if the queue should be partitioned across multiple message brokers . as mentioned above, service bus automatically creates 16 partitions if this is enabled. this also results in maximum size of the queue increase by a factor of 16. this property can only be set during queue creation time . enable deadlettering (enabledeadlettering) indicates if the messages in the queue should be moved to dead-letter sub queue once they expire. if this property is not set, then the messages will be removed from the queue once they expire. enable batching (enablebatchedoperations) indicates if server-side batched operations are supported. this is used to improve the throughput of a queue as service bus holds the messages for up to 20ms before writing/deleting them in a batch. enable message ordering (supportordering) indicates if the queue supports ordering. requires duplicate detection (requiresduplicatedetection) indicates if the queue requires duplicate detection. this property can only be set during queue creation time and is only available for “standard” tier. enable express (enableexpress) indicates if the queue is an express queue. an express queue holds a message in memory temporarily before writing it to persistent storage. this property can only be set during queue creation time and is only available for “standard” tier. requires session (requiressession) indicates if the queue supports the concept of session. this property can only be set during queue creation time and is only available for “standard” tier. auto delete queue this property specifies a time period after which an idle queue should be deleted automatically by service bus . minimum period allowed is 5 minutes. this can only be set for “standard” tier . duplicate detection history time window (duplicatedetectionhistorytimewindow) defines the duration of the duplicate detection history. this can only be set for “standard” tier . forward messages to queue/topic (forwardto) you can use this property to automatically forward messages from a queue to another queue or topic. when setting this property, the queue/topic must exist in the account. this can only be set for “standard” tier . forward dead-lettered messages to queue/topic (forwarddeadletteredmessagesto) you can use this property to automatically forward dead-lettered message to another queue or topic. when setting this property, the queue/topic must exist in the account. user metadata (usermetadata) you can use this property to define any custom metadata for a queue. following table summarizes property applicability by tier and whether they are editable or not. property tier editable? size basic, standard no status basic, standard yes max delivery count basic, standard yes message time to live basic, standard yes lock duration basic, standard yes enable partitioning basic, standard no enable deadlettering basic, standard yes enable batching basic, standard yes enable message ordering basic, standard yes requires duplicate detection standard no enable express standard no require session standard no auto delete queue standard yes duplicate detection history time window standard yes forward messages to queue/topic standard yes forward dead-lettered messages to queue/topic basic, standard yes user metadata basic, standard yes to learn more about these properties, please see this link: https://msdn.microsoft.com/en-us/library/microsoft.servicebus.messaging.queuedescription.aspx . messages the way i see it, messages are the entities that contain information about the work a sender wants a receiver to do. as mentioned earlier, a sender sends a message to a queue and a receiver will receive the message. at any time, a message will be received by one and only one receiver. message processing there’re two ways by which a receiver will receive a message: peek and lock & receive and delete . peek and lock in peek and lock mode, the message is locked by the receiver for a duration specified by queue’s “ lock duration ” property or in other words under this mode a message is hidden from other receivers for a duration specified by lock duration. the receiver then would process the message and after that a receiver would mark the message as “ complete ” which essentially deletes the message from the queue. if the “lock duration” expires, other receivers will be able to fetch this message. receive and delete in receive and delete mode, once the message is received by a receiver it will be deleted from the queue automatically. if a receiver fails to process that message, then the message is lost forever. so unless you’re sure of receiver’s functionality that it will never fail or you don’t care if the message is processed successfully or not, use this mode cautiously. message composition a message in service bus consists of 3 things – message body, standard properties and custom properties. message body is the actual content of the message. there are some predefined properties of a message and those fall under standard properties. apart from that you can define custom properties on a message which are essentially a collection of name/value pairs. total size of a message is 256 kb. message properties now let’s take a look at some of the standard properties of a message that i found interesting. message id this is the identifier of a message. you can set it at the time of sending a message. because it is an identifier, one would assume that it needs to be unique but that’s not the case. different messages can have same message id. sequence number when a message is created, service bus assigns a number to a message. that number is stored in this property. please note that it is a read-only property. message time to live (message ttl) this is the time period for which a message will remain in the queue. if you recall, you can also define a default message time-to-live at queue level also. service bus actually picks the lower of the two values as message ttl. for example, if you have defined that a message will expire after 14 days at queue level but 5 minutes at the message level then the message will expire after 5 minutes. lock token whenever a message is received by a receiver in “ peek and lock ” mode, service bus returns a (lock) token that must be used to perform further operations (e.g. delete message or dead-letter message etc.) on that message. this token is valid for a duration specified by “ lock duration ” property. after the lock duration expires, the lock token becomes invalid and any attempt to use this token for performing any allowed operations will result in an error. once a lock token expires, a receiver must receive the message again. there are other properties as well which i have not included for the sake of brevity. for a complete list of properties, please see this link: https://msdn.microsoft.com/en-us/library/microsoft.servicebus.messaging.brokeredmessage_properties.aspx . summary that’s it for this post. in the next posts in this series, i will share my learning about topics and other service bus services. so stay tuned for that! again, if you think that i have provided some incorrect information, please let me know and i will fix them asap.

[This article was written by Juergen Hoeller.] Spring is well-known to actively support the latest versions of common open source projects out there, e.g. Hibernate and Jackson but also common server engines such as Tomcat and Jetty. We usually do this in a backwards-compatible fashion, supporting older versions at the same time - either through reflective adaptation or through separate support packages. This allows for applications to selectively decide about upgrades, e.g. upgrading to the latest Spring and Jackson versions while preserving an existing Hibernate 3 investment. With the upcoming Spring Framework 4.2, we are taking the opportunity to support quite a list of new open source project versions, including some rather major ones: Hibernate ORM 5.0 Hibernate Validator 5.2 Undertow 1.2 / WildFly 9 Jackson 2.6 Jetty 9.3 Reactor 2.0 SockJS 1.0 final Moneta 1.0 (the JSR-354 Money & Currency reference implementation) While early support for the above is shipping in the Spring Framework 4.2 RCs already, the ultimate point that we’re working towards is of course 4.2 GA - scheduled for July 15th. At this point, we’re eagerly waiting for Hibernate ORM 5.0 and Hibernate Validator 5.2 to GA (both of them are currently at RC1), as well as WildFly 9.0 (currently at RC2) and Jackson 2.6 (currently at RC3). Tight timing… By our own 4.2 GA on July 15th, we’ll keep supporting the latest release candidates, rolling any remaining GA support into our 4.2.1 if necessary. If you’d like to give some of those current release candidates a try with Spring, let us know how it goes. Now is a perfect time for such feedback towards Spring Framework 4.2 GA! P.S.: Note that you may of course keep using e.g. Hibernate ORM 3.6+ and Hibernate Validator 4.3+ even with Spring Framework 4.2. A migration to Hibernate ORM 5.0 in particular is likely to affect quite a bit of your setup, so we only recommend it in a major revision of your application, whereas Spring Framework 4.2 itself is designed as a straightforward upgrade path with no impact on existing code and therefore immediately recommended to all users.

The standard usage of JavaFX TableView with currently available set of cell controls, with all its indisputable merits, fails to meet a fairly important requirement, which usually arises when editable fields are mutually dependent. Generally it is easy enough to change values of all dependent fields when value of some field had been changed. The real problem emerges when a cell control, which is connected with a single data field (property), should become editable or not editable (having a fixed value) depending on values of some other fields (properties) of the same record (row data object). Besides, to spare user some useless clicks and confusion, it is important to make appearance of the cell reflect at least two conditions: editable/not editable and within/outside of the selected row. To make it work, there is no need to subclass anything but table-cell controls. While it is possible to subclass TableCell and recreate all the specific cell controls, it is much easier to subclass each particular cell control, although it does lead to some minor duplication of code. To insure that all our custom cells refer to the same style definitions in a CSS stylesheet, let's share style constants in an interface: public interface IDeCell { public static final String CLASS_DE_CELL = "de-cell"; public static final String PSEUDO_CLASS_NOT_EDITABLE = "not-editable"; public static final String PSEUDO_CLASS_ROW_SELECTED = "row-selected"; } Prefix "de" stands for Dynamic Editability. We are going to prefix our custom cell extensions with "De" and refer to such cells as "de-cells". Here is source code of custom TextFieldTableCell extension: public class DeTextFieldTableCell extends TextFieldTableCell implements IDeCell { private static final PseudoClass NOT_EDITABLE_PSEUDO_CLASS = PseudoClass.getPseudoClass(PSEUDO_CLASS_NOT_EDITABLE); private static final PseudoClass ROW_SELECTED_PSEUDO_CLASS = PseudoClass.getPseudoClass(PSEUDO_CLASS_ROW_SELECTED); public BooleanProperty notEditableProperty() { return notEditable; } public final boolean isNotEditable() { return notEditableProperty().get(); } private final BooleanProperty notEditable = new SimpleBooleanProperty(this, PSEUDO_CLASS_NOT_EDITABLE, false) { @Override protected void invalidated() { pseudoClassStateChanged(NOT_EDITABLE_PSEUDO_CLASS, get()); } }; public final BooleanProperty rowSelectedProperty() { return rowSelected; } public final boolean isRowSelected() { return rowSelectedProperty().get(); } private final BooleanProperty rowSelected = new SimpleBooleanProperty(this, PSEUDO_CLASS_ROW_SELECTED, false) { @Override protected void invalidated() { pseudoClassStateChanged(ROW_SELECTED_PSEUDO_CLASS, get()); } }; public SimpleObjectProperty recordProperty() { return record; } private SimpleObjectProperty record = new SimpleObjectProperty<>(); public DeTextFieldTableCell(StringConverter converter) { super(converter); getStyleClass().add(CLASS_DE_CELL); notEditable.bind(editableProperty().not()); tableRowProperty().addListener((ov, vOld, vNew)-> { record.unbind(); rowSelected.unbind(); if (vNew != null) { record.bind(vNew.itemProperty()); rowSelectedProperty().bind(vNew.selectedProperty()); } }); } } DeTextFieldTableCell and all other de-cell controls share identical lines of code which define Boolean properties "rowSelected" and "notEditable" and respective custom CSS pseudo-classes "row-selected" and "not-editable". Additionally, de-cells expose row object (record) with "record" property. Code, which makes editability and appearance of a cell depend on values of one or more properties of the "record" has to look like this: cell.recordProperty().addListener((ov, r0, r) -> { cell.editableProperty().unbind(); if (r != null) { cell.editableProperty().bind(r.someProperty().and(r.otherProperty())); } }); Here is sample CSS for de-cells: .de-cell:filled:not-editable { -fx-background-color: #cccccc; -fx-text-fill: #0000ff; -fx-border-width: 1px 0px 0px 1px; -fx-border-color: #eeeeee } .de-cell:filled:row-selected { -fx-background-color: skyblue; -fx-text-fill: black; -fx-border-width: 1px 0px 0px 1px; -fx-border-color: #eeeeee } .de-cell:filled:not-editable:row-selected { -fx-background-color: #999999; -fx-text-fill: #0000ff } The example below is a taken (with some simplification) from the existing working application. There is a system, which allows customers to buy online prints and file downloads. All general, non-specific files, which are accessible by general customers, have preassigned General Prices: price of 1 printed copy for printable and download price for not printable ones. Besides, there are special, tailor-made files, which are not accessible by general customers and don't have General Prices. A customer can fetch products himself (with General Price only), or some products can be pushed to him by a sales manager - with General Price or (relatively reduced) Special Price. In the first case number of the printed copies to be chosen by the customer, whereas in the last case number of printed copies has to be limited by the sales manager. In case of special, tailor-made files Special Price has to be assigned. Number of copies (quantity) for the file download is always equal 1. At some point a sales manager collects all products (both general and tailor-made) to be pushed to a customer and has to edit collected entries. He/She can change any general price to a special one, allow download of a printable product, edit Special prices and printed copies (quantities). There are following dependencies: 1. General/Special choice is enabled for the general products only. 2. Print/Download choice is enabled for printable products when Special Price is selected. 3. Price is editable when Special Price is selected, otherwise it has to be equal to preassigned General Price. 4. Quantity is editable when Special Price and Print Service are selected. When Download selected quantity is fixed and equals 1, when General and Print selected quantity is null (to be chosen by customer). For example, for a sample product "*A: General Print" the only editable dynamic field is "Price Type". If a user changes Price Type to Special then Service Type, Item Price and Quantity become editable. If a user changes Service Type to Download then Quantity become not editable (and set to 1). Here is source code for data object Entry: public class Entry { private final IntegerProperty entryId = new SimpleIntegerProperty(); private final StringProperty name = new SimpleStringProperty(); private final BooleanProperty printable = new SimpleBooleanProperty(); private final BooleanProperty useGeneralPrice = new SimpleBooleanProperty(); private final BooleanProperty usePrintService = new SimpleBooleanProperty(); private final ObjectProperty generalPrice = new SimpleObjectProperty<>(); private final ObjectProperty price = new SimpleObjectProperty<>(); private final ObjectProperty quantity = new SimpleObjectProperty<>(); private final ObjectProperty totalPrice = new SimpleObjectProperty<>(); public IntegerProperty entryIdProperty() { return entryId; } public StringProperty nameProperty() { return name; } public BooleanProperty printableProperty() { return printable; } public BooleanProperty useGeneralPriceProperty() { return useGeneralPrice; } public BooleanProperty usePrintServiceProperty() { return usePrintService; } public ObjectProperty generalPriceProperty() { return generalPrice; } public ObjectProperty priceProperty() { return price; } public ObjectProperty quantityProperty() { return quantity; } public ObjectProperty totalPriceProperty() { return totalPrice; } public Entry(int aEntryId, String aName, BigDecimal aGeneralPrice, boolean aPrintable) { entryId.set(aEntryId); name.set(aName); printable.set(aPrintable); useGeneralPrice.set(aGeneralPrice != null); usePrintService.set(aPrintable); generalPrice.set(aGeneralPrice); price.set(aGeneralPrice); quantity.set((aPrintable) ? null : 1); totalPrice.bind(new ObjectBinding() { { super.bind(price, quantity); } @Override protected Number computeValue() { return (price.get() == null || quantity.get() == null) ? null : price.get().doubleValue()*quantity.get(); } }); } } Here is an excerpt from the sample app - creation of table columns with de-cells: TableColumn priceTypeCol = new TableColumn<>("Price Type"); priceTypeCol.setPrefWidth(60); priceTypeCol.setCellValueFactory(new PropertyValueFactory<>("useGeneralPrice")); priceTypeCol.setCellFactory((tableColumn) -> { DeComboBoxTableCell cell = new DeComboBoxTableCell<>( new ABooleanConverter(PRICE_TYPES[0], PRICE_TYPES[1]), true, false); cell.recordProperty().addListener((ov, vOld, vNew) -> { cell.editableProperty().unbind(); if (vNew != null) cell.editableProperty().bind(vNew.generalPriceProperty().isNotNull()); }); return cell; }); priceTypeCol.setOnEditCommit((ev) -> { Entry entry = ev.getRowValue(); Boolean value = ev.getNewValue(); entry.useGeneralPriceProperty().set(value); if (value) { entry.priceProperty().set(entry.generalPriceProperty().get()); entry.usePrintServiceProperty().set(entry.printableProperty().get()); } entry.quantityProperty().set( (value && entry.usePrintServiceProperty().get()) ? null : 1); }); //============================================================== TableColumn serviceTypeCol = new TableColumn<>("Service Type"); serviceTypeCol.setPrefWidth(60); serviceTypeCol.setCellValueFactory(new PropertyValueFactory<>("usePrintService")); serviceTypeCol.setCellFactory((tableColumn) -> { DeComboBoxTableCell cell = new DeComboBoxTableCell<>( new ABooleanConverter(SERVICE_TYPES[0], SERVICE_TYPES[1]), true, false); cell.recordProperty().addListener((ov, vOld, vNew) -> { cell.editableProperty().unbind(); if (vNew != null) { cell.editableProperty().bind(vNew.useGeneralPriceProperty().not() .and(vNew.printableProperty())); } }); return cell; }); serviceTypeCol.setOnEditCommit((ev) -> { Entry entry = ev.getRowValue(); Boolean value = ev.getNewValue(); entry.usePrintServiceProperty().set(value); entry.quantityProperty().set(1); }); //============================================================== TableColumn priceCol = new TableColumn<>("Item Price"); priceCol.setPrefWidth(50); priceCol.setCellValueFactory(new PropertyValueFactory<>("price")); priceCol.setCellFactory((tableColumn) -> { DeTextFieldTableCell cell = new DeTextFieldTableCell<>( new AMoneyConverter()); cell.setAlignment(Pos.CENTER_RIGHT); cell.recordProperty().addListener((ov, vOld, vNew) -> { cell.editableProperty().unbind(); if (vNew != null) cell.editableProperty().bind(vNew.useGeneralPriceProperty().not()); }); return cell; }); priceCol.setOnEditCommit((ev) -> { ev.getRowValue().priceProperty().set(ev.getNewValue()); }); //============================================================== TableColumn quantityCol = new TableColumn<>("Quantity"); quantityCol.setPrefWidth(40); quantityCol.setCellValueFactory(new PropertyValueFactory<>("quantity")); quantityCol.setCellFactory((tableColumn) -> { DeTextFieldTableCell cell = new DeTextFieldTableCell<>( new IntegerStringConverter()); cell.setAlignment(Pos.CENTER); cell.recordProperty().addListener((ov, vOld, vNew) -> { cell.editableProperty().unbind(); if (vNew != null) { cell.editableProperty().bind(vNew.useGeneralPriceProperty().not() .and(vNew.usePrintServiceProperty())); } }); return cell; }); priceCol.setOnEditCommit((ev) -> { ev.getRowValue().priceProperty().set(ev.getNewValue()); }); //============================================================== TableColumn totalPriceCol = new TableColumn<>("Total Price"); totalPriceCol.setPrefWidth(50); totalPriceCol.setCellValueFactory(new PropertyValueFactory<>("totalPrice")); totalPriceCol.setCellFactory((tableColumn) -> { DeTextFieldTableCell cell = new DeTextFieldTableCell<>( new AMoneyConverter()); cell.setAlignment(Pos.CENTER_RIGHT); cell.setEditable(false); return cell; }); totalPriceCol.setEditable(false); --

When it comes to teaching or learning, video streaming is something that still frightens people away. As a matter of fact that video chats and webinars have been around for a relatively long time, however; its still hard to encourage an individual or business to take part as such. And yet the benefits of CaptainLive can be substantial in both, short as well as long term. As we have already seen the benefits of video marketing therefore, we want to encourage you to use CaptainLive in order to take advantage of your potential whether it’s hidden in you or you are well aware of it. CaptainLive was launched in early 2015 with a mission to connect people in need of knowledge and skills with Captains with Benefits that are willing to share and give their expertise and mentor skills. CaptainLive’s integrated service now allows for text, video and audio conferencing. It’s been used by a variety of individuals with different backgrounds. At CaptainLive you can schedule an online live video stream with the experts in number topics ranging from counseling up to entertainment. Captains/Experts on the site charges from $5 USD up to $150 USD, most of which offer free 5 minute sessions with no obligation to book their session thereafter. Who knows you might end up registering as Captain yourself and start a part time business of your own to help others with your skills while making a healthy stream of income for yourself, it’s surely well worth your effort.

Continuing my Spring-Cloud learning journey, earlier I had covered how to write the infrastructure components of a typical Spring-Cloud and Netflix OSS based micro-services environment - in this specific instance two critical components, Eureka to register and discover services and Spring Cloud Configuration to maintain a centralized repository of configuration for a service. Here I will be showing how I developed two dummy micro-services, one a simple "pong" service and a "ping" service which uses the "pong" service. Sample-Pong microservice The endpoint handling the "ping" requests is a typical Spring MVC based endpoint: @RestController public class PongController { @Value("${reply.message}") private String message; @RequestMapping(value = "/message", method = RequestMethod.POST) public Resource pongMessage(@RequestBody Message input) { return new Resource<>( new MessageAcknowledgement(input.getId(), input.getPayload(), message)); } } It gets a message and responds with an acknowledgement. Here the service utilizes the Configuration server in sourcing the "reply.message" property. So how does the "pong" service find the configuration server, there are potentially two ways - directly by specifying the location of the configuration server, or by finding the Configuration server via Eureka. I am used to an approach where Eureka is considered a source of truth, so in this spirit I am using Eureka to find the Configuration server. Spring Cloud makes this entire flow very simple, all it requires is a "bootstrap.yml" property file with entries along these lines: --- spring: application: name: sample-pong cloud: config: discovery: enabled: true serviceId: SAMPLE-CONFIG eureka: instance: nonSecurePort: ${server.port:8082} client: serviceUrl: defaultZone: http://${eureka.host:localhost}:${eureka.port:8761}/eureka/ The location of Eureka is specified through the "eureka.client.serviceUrl" property and the "spring.cloud.config.discovery.enabled" is set to "true" to specify that the configuration server is discovered via the specified Eureka server. Just a note, this means that the Eureka and the Configuration server have to be completely up before trying to bring up the actual services, they are the pre-requisites and the underlying assumption is that the Infrastructure components are available at the application boot time. The Configuration server has the properties for the "sample-pong" service, this can be validated by using the Config-servers endpoint - http://localhost:8888/sample-pong/default, 8888 is the port where I had specified for the server endpoint, and should respond with a content along these lines: "name": "sample-pong", "profiles": [ "default" ], "label": "master", "propertySources": [ { "name": "classpath:/config/sample-pong.yml", "source": { "reply.message": "Pong" } } ] } As can be seen the "reply.message" property from this central configuration server will be used by the pong service as the acknowledgement message Now to set up this endpoint as a service, all that is required is a Spring-boot based entry point along these lines: @SpringBootApplication @EnableDiscoveryClient public class PongApplication { public static void main(String[] args) { SpringApplication.run(PongApplication.class, args); } } and that completes the code for the "pong" service. Sample-ping micro-service So now onto a consumer of the "pong" micro-service, very imaginatively named the "ping" micro-service. Spring-Cloud and Netflix OSS offer a lot of options to invoke endpoints on Eureka registered services, to summarize the options that I had: 1. Use raw Eureka DiscoveryClient to find the instances hosting a service and make calls using Spring's RestTemplate. 2. Use Ribbon, a client side load balancing solution which can use Eureka to find service instances 3. Use Feign, which provides a declarative way to invoke a service call. It internally uses Ribbon. I went with Feign. All that is required is an interface which shows the contract to invoke the service: package org.bk.consumer.feign; import org.bk.consumer.domain.Message; import org.bk.consumer.domain.MessageAcknowledgement; import org.springframework.cloud.netflix.feign.FeignClient; import org.springframework.http.MediaType; import org.springframework.web.bind.annotation.RequestBody; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import org.springframework.web.bind.annotation.ResponseBody; @FeignClient("samplepong") public interface PongClient { @RequestMapping(method = RequestMethod.POST, value = "/message", produces = MediaType.APPLICATION_JSON_VALUE, consumes = MediaType.APPLICATION_JSON_VALUE) @ResponseBody MessageAcknowledgement sendMessage(@RequestBody Message message); } The annotation @FeignClient("samplepong") internally points to a Ribbon "named" client called "samplepong". This means that there has to be an entry in the property files for this named client, in my case I have these entries in my application.yml file: samplepong: ribbon: DeploymentContextBasedVipAddresses: sample-pong NIWSServerListClassName: com.netflix.niws.loadbalancer.DiscoveryEnabledNIWSServerList ReadTimeout: 5000 MaxAutoRetries: 2 The most important entry here is the "samplepong.ribbon.DeploymentContextBasedVipAddresses" which points to the "pong" services Eureka registration address using which the service instance will be discovered by Ribbon. The rest of the application is a routine Spring Boot application. I have exposed this service call behind Hystrix which guards against service call failures and essentially wraps around this FeignClient: package org.bk.consumer.service; import com.netflix.hystrix.contrib.javanica.annotation.HystrixCommand; import org.bk.consumer.domain.Message; import org.bk.consumer.domain.MessageAcknowledgement; import org.bk.consumer.feign.PongClient; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Qualifier; import org.springframework.stereotype.Service; @Service("hystrixPongClient") public class HystrixWrappedPongClient implements PongClient { @Autowired @Qualifier("pongClient") private PongClient feignPongClient; @Override @HystrixCommand(fallbackMethod = "fallBackCall") public MessageAcknowledgement sendMessage(Message message) { return this.feignPongClient.sendMessage(message); } public MessageAcknowledgement fallBackCall(Message message) { MessageAcknowledgement fallback = new MessageAcknowledgement(message.getId(), message.getPayload(), "FAILED SERVICE CALL! - FALLING BACK"); return fallback; } } Boot"ing up I have dockerized my entire set-up, so the simplest way to start up the set of applications is to first build the docker images for all of the artifacts this way: mvn clean package docker:build -DskipTests and bring all of them up using the following command, the assumption being that both docker and docker-compose are available locally: docker-compose up Assuming everything comes up cleanly, Eureka should show all the registered services, at http://dockerhost:8761 url - The UI of the ping application should be available at http://dockerhost:8080 url - Additionally a Hystrix dashboard should be available to monitor the requests to the "pong" app at this url http://dockerhost:8989/hystrix/monitor?stream=http%3A%2F%2Fsampleping%3A8080%2Fhystrix.stream: References 1. The code is available at my github location - https://github.com/bijukunjummen/spring-cloud-ping-pong-sample 2. Most of the code is heavily borrowed from the spring-cloud-samples repository - https://github.com/spring-cloud-samples

This is the third in a series of interviews for you to meet some of the committee members for the JavaOne 2015 Java EE track. The committee plays the most important part in determining the content for JavaOne. These good folks really deserve recognition as most of them devote many hours of their time helping move JavaOne forward, often as volunteers. If JavaOne matters to you, these are folks you should know about. This interview is with Johan Vos. If you are having trouble seeing the embedded video below it is available here. Johan is a Java Champion, author, speaker, blogger, member of the BeJUG steering group, member of the Devoxx steering group and a JCP member. He is a fan of Java EE, GlassFish and JavaFX. He founded LodgON, a company offering Java based solutions for social networking software. In the interview he shares his experience and expectations for the Java EE track this year. On this note, I would like to make sure you know that the JavaOne content catalog is now already live with a few preliminary fairly obvious selections we were able to make. None of the sessions accepted at this stage are from Oracle speakers on our track. The folks that we selected early for acceptance include David Blevins, Jonathan Gallimore, Mohammed Taman, Rafael Benevides and Antoine Sabot-Durand. They will be talking about Java EE Connectors (JCA), Java EE 7 real world adoption, CDI and DeltaSpike. I would encourage you to check out all the early selections in the catalog. We are working to finalize the full catalog shortly. I hope to see you at JavaOne. Do stay tuned for more interviews with committee members and some key speakers on our track.

In mathematics an automorphic number (sometimes referred to as a circular number) is a number whose square "ends" in the same digits as the number itself. For example, 52 = 25, 62 = 36, 762 = 5776, and 8906252 = 793212890625, so 5, 6, 76 and 890625 are all automorphic numbers. And the logic behind : int n=56; int d=1; int i; for(i=n;i>0;i=i/10) { d=d*10; } if((n*n)%d==n) { System.out.println(n+"\t"+"is Automorphic Number"); } else { System.out.println(n+"\t"+"is not Automorphic Number"); } } You can check full article from Geek On Java - Hub for Java and Android

Rework is Hell “Software may be eating the world, but rework is choking software”, tweeted John Jeremiah (@j_jeremiah). To shed more light on what is choking software, new data was released last week in the 2015 State of the Software Supply Chain Report. In its discussion of application quality and integrity, the report revealed that the average application includes 106 open source components. It is clear that the use of these components has benefited development tremendously in helping to speed time to market and improve innovation. While the benefits are undeniable, development teams are also delivering applications that are “insecure by design”. Of the 106 components per application, the report’s analysis revealed an average of 24 (i.e., 23%) have known critical or severe security vulnerabilities. Those same apps also showed an average of 9 restrictive license types (e.g., GPL, AGPL, LGPL). By electively sourcing components with known vulnerabilities and potential license risks, software development teams are building up higher levels of technical and security debt. And in order to reduce some of that debt, unplanned and unscheduled rework is often required. No Developer Intentionally Uses Bad Parts I have never met a developer that intentionally wanted to use “bad” components in their applications. That said, I have also never met a developer that wanted to spend four hours researching the latest versions, open source licenses and known security vulnerabilities for components (including dependencies) they wanted to use in their applications. While 57% of development organizations have internal policies in place that direct “thou shall not use components with poor quality and integrity”, many have stated that the policies are not followed or are simply not enforced. The problem is one of volume and velocity, while people clutch to old processes that simply can’t keep pace. The analysis in the 2015 State of the Software Supply Chain report revealed that billions of open source downloads occurred in 2014, of which 6.2% had known vulnerabilities (1 in 16 downloads). For some large companies, the volume of downloads exceeded 240,000 — where 15,000 (7.5%) had known security vulnerabilities. At these volumes, manual processes and paper-based policies to prevent poor quality or risky components from getting into your software have no possibility of keeping pace. While software development practices aim for higher velocity, through component-based development as well as Agile, continuous and DevOps practices, the processes to keep up with it have not changed enough. The only way to keep pace with this velocity is through automation. And if we want to avoid unplanned rework associated with remediating known security vulnerabilities or selecting alternative components with approved license types, automation has to become the norm rather than the exception within development. At Speed “If I look at the mass, I will never act. If I look at the one, I will.” — Mother Teresa Looking at the massive volume and velocity of open source and other artifact consumption can be discouraging and overwhelming. However, the volume and velocity within our software supply chains will not diminish—and without a new approach, the volume of unchecked quality and integrity of parts being consumed will continue to build up as technical debt. Automation in areas of testing, build, and deployment has provided significant performance benefits. Likewise, investments in software supply chain automation have shown markedly improved efficiency and controlled risk, as the best practices in the 2015 Report illustrate. Automation can unleash the potential of an organization’s development capacity. Rarely is there such an opportunity to simultaneously increase speed, efficiency, and quality. In order to improve the quality and integrity of components used in our applications, we need to release our clutch on old practices. We can further embrace automation across our software supply chains — and improve the quality of our applications — by considering these three steps: 1. Start with creating a software bill of materials for one application. Visibility into one application can help you better understand your current component usage. A number of free and paid services are available to help you create a software bill of materials within a few minutes. The bill of materials will help you to identify the unique component parts used within your application and the suppliers who contributed them. These reports list all components used, and several services also identify component age, popularity, version numbers, licenses, and known vulnerabilities. 2. Design approval processes to be frictionless, scalable, and automated. Manual reviews of components and suppliers cannot keep pace with the current volume and velocity of consumption. Your organization must not only define your policies for supplier and part selection but also find practical ways to enforce them without slowing down development or inadvertently encouraging workarounds. Policies must be agile enough to keep pace with modern development. Strive to automate policy enforcement and minimize drag on developers. 3. Enable developer decision support. Developers are primary consumers of components in software supply chains. They initiate every component request. Help developers by automating the availability of information on component versions, age, popularity, licenses, and known vulnerabilities within their existing development tools so it is easy to pick the best components from the start. By selecting the highest-quality components from the highest-quality suppliers early, you will improve developer productivity and reduce costs. Here is the complete 2015 State of the Software Supply Chain Report. I will also be discussing more of the Report findings and best practices on a webinar scheduled for Wednesday, June 24, 12pm ET (register or view it on-demand). The previous blog in this series was, Fewer and Better Suppliers. Next up, I will be reviewing Visibility and Traceability practices across the software supply chain with more commentary from the 2015 State of the Software Supply Chain Report.

Originally authored by Elizabeth Engel You are thinking about including some nice charts and graphics into your current project? Maybe you heard about D3.js, as some people claim it the universal JavaScript visualization framework. Maybe you also heard about a steep learning curve. Let’s see if this is really true! First of all, what is D3.js? D3.js is an open source JavaScript framework written by Mike Bostock helping you to manipulate documents based on data. Okay, let’s first have a look at the syntax Therefore, lets look at the following hello world example. It will append an element saying ‘Hello World!’ to the content element. As you can see the syntax is very similar to frameworks like JQuery and obviously, it saves you a lot of code lines as it offers a nice fluent API. But let’s see how we can bind data to it: d3.select('#content') .selectAll('h1') .data(['Sarah', 'Robert', 'Maria', 'Marc']) .enter() .append('h1') .text(function(name) {return 'Hello ' + name + '!'}); What happens? The data function gets our names array as parameter and for each name we append an element with a personalized greeting message. For a second, we ignore the selectAll(‘h1′) and enter() method call, as we will explore them later. Looking into the browser we can see the following: Hello Sarah! Hello Robert! Hello Maria! Hello Marc! Not bad for a start! Inspecting the element in the browser, we see the following generated markup: [...] Hello Sarah! Hello Robert! Hello Maria! Hello Marc! [...] This already shows one enourmous advantage of D3.js: You acctually see the generated code and can spot errors easily. Now, let’s have a closer look at the data-document connection As mentioned in the beginning, D3.js helps you to manipulate documents based on data. Therefore, we only take care about handing the right data over to D3.js, so the framework can do the magic for us. To understand how D3.js handles data, we’ll first have a look at how data might change over time. Let’s take the document from our last example. Every name is one data entry. Easy. Now let’s assume new data comes in: As new data is coming in, the document needs to be updated. The entries of Robert and Maria need to be removed, Sarah and Marc can stay unchanged and Mike, Sam and Nora need a new entry each. Fortunately, using D3.js we don’t have to care about finding out which nodes need to be added and removed. D3.js will take care about it. It will also reuse old nodes to improve performance. This is one key benefit of D3.js. So how can we tell D3.js what to do when? To let D3.js update our data, we initially need a data join, so D3.js knows our data. Therefore, we select all existing nodes and connect them with our data. We can also hand over a function, so D3.js knows how to identify data nodes. As we initally don’t have nodes, the selectAll function will return an empty set. var textElements = svg.selectAll('h1').data(data, function(d) { return d; }); After the first iteration, the selectAll will hand over the existing nodes, in our case Sarah, Robert, Marc and Maria. So we can now update these existing nodes. For example, we can change their CSS class to grey: textElements.attr({'class': 'grey'}); Additionally, we can tell D3.js what to do with entering nodes, in our case Mike, Sam and Nora. For example, we can add an element for each of them and set the CSS class to green for each of them: textElements.enter().append('h1').attr({'class': 'green'}); As D3.js now updated the old nodes and added the new ones, we can define what will happen to both of them. In our cases this will affect the nodes of Mike, Sarah, Sam, Mark and Nora. For example, we can rotate them: textElements.attr({'transform', rotate(30 20,40)}); Furthermore, we can specify what D3.js will do to nodes like Robert and Maria, that are not contained in the data set any more. Let’s change their CSS class to red: textElements.exit().attr({'class': 'red'}); You can find the full example code to illustrate the data-document connection of D3.js as JSFiddle here: https://jsfiddle.net/q5sgh4rs/1/ But how to visualize data with D3.js? Now that we know about the basics of D3.js, let’s go to the most interesting part of D3.js: drawing graphics. To do so, we use SVG, which stands for scalable vector graphics. Maybe you already know it from other contexts. In a nutshell, it’s a XML-based vector image language supporting animation and interaction. Fortunately, we can just add SVG tags in our HTML and all common browsers will display it directly. This also facilitates debugging, as we can inspect generated elements in the browser. In the following, we see some basic SVG elements and their attributes: To get a better understanding of how SVG looks like, we’ll have a look at it as a basic example of SVG code, generating a rectangle, a line and a circle. To generate the same code using D3.js, we need to add an SVG to our content and then append the tree elements with their attributes like this: var svg = d3.select('#content').append('svg'); svg.append('rect').attr({x: 10, y: 15, width: 60, height: 20}); svg.append('line').attr({x1: 85, y1: 35, x2: 105, y2: 15}); svg.append('circle').attr({cx: 130, cy: 25, r: 6}); Of course, for static SVG code, we wouldn’t do this, but as we already saw, D3.js can fill attributes with our data. So we are now able to create charts! Let’s see how this works: This will draw our first bar chart for us! Have a look at it: https://jsfiddle.net/tLhomz11/2/ How to turn this basic bar chart into an amazing one? Now that we started drawing charts, we can make use of all the nice features D3.js offers. First of all, we will adjust the width of each bar to fill the available space by using a linear scale, so we don’t have to scale our values by hand. Therefore, we specify the range we want to get values in and the domain we have. In our case, the data is in between 0 and 200 and we would like to scale it to a range of 0 to 400, like this: var xScale = d3.scale.linear().range([0, 400]).domain([0,200]); If we now specify x values, we just use this function and get an eqivalent value in the right range. If we don’t know our maximum value for the domain, we can use the d3.max() function to calculate it based on the data set we want to display. To add an axis to our bar chart, we can use the following function and call it on our SVG. To get it in the right position, we need to transform it below the chart. [svg from above].call(d3.svg.axis().scale(xScale).orient("bottom")); Now, we can also add interaction and react to user input. For example, we can give an alert, if someone clicks one our chart: [svg from above].on("click", function () { alert("Houston, we get attention here!"); }) Adding a text node for each line, we get the following chart rendered in the browser: If you would like to play around with it, here is the code: https://jsfiddle.net/Loco5ddt/ If you would like to see even more D3.js code, using the same data to display a pie chart and adding an update button, look at the following one: https://jsfiddle.net/4eqzyquL/ Data import Finally, we can import our data in CSV, TSV or JSON format. To import a JSON file, for example, use the following code. Of course, you can also fetch your JSON via a server call instead of importing a static file. d3.json("data.json", function(data) { [access your data using the data variable] } What else does D3,js offer? Just to name a few, D3.js helps you with layouts, geometry, scales, ranges, data transformation, array and math functions, colors, time formating and scales, geography, as well as drag & drop. There are a lot of examples online: https://github.com/mbostock/d3/wiki/Gallery TL;DR + based on web standards + totally flexible + easy to debug + many, many examples online + Libaries build on D3.js (NVD3.js, C3.js or IVML) – a lot of code compared to other libraries – for standard charts too heavy Learning more As this blog post is based on a presentation held at the MunichJS Meetup, you can find the original slides here: http://slides.com/elisabethengel/d3js#/ The recording is available on youTube: https://www.youtube.com/watch?v=EYmJEsReewo For further information, have a look at: https://github.com/mbostock/d3/wiki https://github.com/mbostock/d3/wiki/API-Reference http://bost.ocks.org/mike/ Getting Started with D3 by Mike Dewar Interactive Data Visualization for the Web by Scott Murray (online for free) https://github.com/alignedleft/d3-book If you have any questions or suggestions, feel free to comment or write me: [email protected]

Curated TED Talk playlists integrated within Cornerstone Learning enable organisations to instantly access new, innovative ideas and share knowledge across their workforce June 30, 2015 - Cornerstone OnDemand, a global leader in cloud-based talent management software solutions, today announced the company is teaming with TED, the non-profit global community devoted to spreading ideas, to deliver curated TED Talks to Cornerstone clients for a new, innovative approach to professional learning and development. The first and only collaboration of its kind, Cornerstone clients now have the ability to provide their workforce with modern, mobile-enabled TED Talks from world-class leaders at the forefront of their fields from within Cornerstone Learning. Cornerstone's collaborative learning functionality also allows organisations to enable peer-to-peer knowledge capture and discussions that can extend the learning impact of TED Talks. Watched and listened to more than 1 billion times this year, TED Talks introduce ideas that can help companies transform how their people think and work. Cornerstone clients will have access to a series of curated TED Talk playlists designed to address key business challenges in an innovative format that is unique, powerful and inspiring. With curated TED Talk playlists through Cornerstone: Inspire your workforce. TED brings together the world's most inspiring and ingenious people whose ideas can strengthen how professionals understand and think about the world around them. TED's curation of talks on behalf of Cornerstone can help organisations generate excitement and engagement among employees, help management crystallise goals, start important conversations, and spark collaborations. Provide the best, most relevant content. Organisations will gain access to the very best collections of TED Talks across a wide range of topics that are central to innovation and talent development, including change management, culture building, leadership, technology, globalisation, diversity and design. Playlists have been curated to reflect talks from visionary leaders across the most influential industries, such as healthcare, education, technology, manufacturing, finance and more. Amplify the value of your learning and development strategy. Employees can view TED Talks from within Cornerstone Learning, the global learning management system (LMS) for over 1,800 leading organisations. Integrating TED Talks into professional development curriculum allows organisations to inspire each individual employee at any stage in their career. Organisations can easily target and deliver learning and development to groups or individuals with the support of TED Talks and measure impact on workforce development from within Cornerstone. Watch and Share Instantly on Mobile: As smartphones emerge as the leading platform for watching video and Web content among busy professionals, TED Talks allow employees to consume and share content on their mobile devices while on the go. Comments on the News "TED Talks are brilliantly crafted and make an emotional connection with viewers. Their ability to convey innovative and complex ideas through powerful, first-person stories is the type of talent management content that can inspire and drive real change in the workforce," said Kirsten Helvey, senior vice president, client success, Cornerstone OnDemand. "We are dedicated to helping people reach their potential by providing our clients with the most innovative talent management solutions that support their professional development and training initiatives." "With the growing demand from companies for TED Talks, Cornerstone provides TED with the expertise and efficiency in reaching millions of learners in organisations across the globe that can benefit from our content," said Deron Triff, TED's director of global distribution and licensing. "This collaboration also provides TED with an important opportunity to understand how the talks can be utilised for professional development to strengthen how we collaborate with the business community. Cornerstone will be a great alliance for bringing TED Talks to companies and sparking innovation among their employees." Additional Resources Learn more about curated TED Talk playlists for Cornerstone via the Cornerstone Marketplace: marketplace.csod.com/#/content/90 Read additional commentary by Cornerstone's director of talent management, Jeff Miller, on the value and influence of TED Talks for empowering today's workforce via the Cornerstone blog: www.cornerstoneondemand.com/blog/how-ted-gets-your-workforce-talking

I presented a new talk at GOTO Chicago 2015 about how to change a team’s attitude towards writing automated tests. The talk covers the same case study as Groovy vs Java for Testing, adopting Spock in MongoDB, but this is a more process/agile/people perspective, not a technical look at the merits of one language over another. Slides available below. As always, the slides are not super-useful out of context, but they do contain my conclusions (also note that due to a technology fail, my hand-drawn style is even more hand-drawn than usual). Questions I sadly did not have a lot of time for questions during the presentation, but thanks to the wonders of modern technology, I have a list of unanswered questions which I will attempt to address here. Is testing to find out your system works? Or is it so you know when your system is broken? Excellent question. I would expect that if you have a system that’s in production (which is probably the large majority of the projects we work on), we can assume the system is working, for some definition of working. Automated testing is particularly good at catching when your system stops doing the things you thought it was doing when you wrote the tests (which may, or may not, mean the system is genuinely “broken”). Regression testing is to find out when your system is no longer doing what you expect, and automated tests are really good for this. But testing can also make sure you implement code that behaves the way you expect, especially if you write the tests first. Automated tests can be used to determine that your code is complete, according to some pre-agreed specification (in this case, the automated tests you wrote up front). So I guess what I’m trying to say is, when you first write the tests you have tests that, when they pass, proves the system works (assumingyour tests are testing the right things and/or not giving you false positives). Subsequent passes show that you haven’t broken anything. At what level do “tests documenting code” actually become useful? And who is/should the documentation be targeted to? In the presentation, my case study is the MongoDB Java Driver. Our users were Java programmers, who were going to be coding using our driver. So in this example, it makes a lot of sense to document the code using a language that our users understood. We started with Java, and ended up using Groovy because it was also understandable for our users and a bit more succinct. On a previous project we had different types of tests. The unit and system tests documented what the expected behaviour was at the class or module level, and was aimed at developers in the team. The acceptance tests were written in Java, but in a friendly DSL-style way. These were usually written by a triad of tester, business analyst and developer, and documented to all these guys and girls what the top-level behaviour should be. Our audience here was fairly technical though, so there was no need to go to the extent of trying to write English-language-style tests, they were readable enough for a reasonably techy (but non-programmer) audience. These were not designed to be read by “the business” - us developers might use them to answer questions about the behaviour of the system, but they didn’t document it in a way that just anyone could understand. These are two different approaches for two different-sized team/organisations, with different users. So I guess in summary the answer is “it depends”. But at the very least, developers on your own team should be able to read your tests and understand what the expected behaviour of the code is. How do you become a team champion? I.e. get authority and acceptance that people listen to you? In my case, it was just by accident - I happened to care about the tests being green and also being useful, so I moaned at people until it happened. But it’s not just about nagging, you get more buy-in if other people see you doing the right things the right way, and it’s not too painful for them to follow your example. There are going to be things that you care about that you’ll never get other people to care about, and this will be different from team to team. You have two choices here - if you care that much, and it bothers you that much, you have to do it yourself (often on your own time, especially if your boss doesn’t buy into it). Or, you have to let it go - when it comes to quality, there are so many things you could care about that it might be more beneficial to drop one cause and pick another that you can get people to care about. For example, I wanted us to use assertThat instead of assertFalse (or true, or equals, or whatever). I tried to demo the advantages (as I saw them) of my approach to the team, and tried to push this in code reviews, but in the end the other developers weren’t sold on the benefits, and from my point of view the benefits weren’t big enough to force the issue. Those of us who cared, used assertThat. For the rest, I was just happy people were writing and maintaining tests. So, pick your battles. You’ll be surprised at how many people do get on board with things. I thought implementing checkstyle and setting draconian formatting standards was going to be a tough battle, but in the end people were just happy to have any standards, especially when they were enforced by the build. Do you report test, style, coverage, etc failures separately? Why? We didn’t fail on coverage. Enforcing a coverage percentage is a really good way to end up with crappy tests, like for getters/setters and constructors (by the way, if there’s enough logic in your constructor that it needs a test, You’re Doing It Wrong). Generally different types of failures are found by different tools, so for this reason alone they will be reported separately - for example, checkstyle will fail the build if it doesn’t conform to our style standards, codenarc fails it for Groovy style failures, and Gradle will run the tests in a different task to these two. What’s actually important, though, is time-to-failure. For checkstyle, for example, it will fail on something silly like curly braces in the wrong place. You want this to fail within seconds, so you can fix the silly mistake quickly. Ideally you’d have IntelliJ (perhaps) run your checks before it even makes it into your CI environment. Compiler errors should, of course, fail things before you run a test, short-running tests should fail before long-running tests. Basically, the easier it is to fix the problem, the sooner you want to know, I guess. Our build was relatively small and not too complex, so actually we ran all our types of tests (integration and unit, both Groovy and Java) in a single task, because this turned out to be much quicker in Gradle (in our case) than splitting things up into a simple pipeline. You might have a reason to report stuff separately, but for me it’s much more important to understand how fast I need to be aware of a particular type of failure. Sometimes I find myself modifying code design and architecture to enable testing. How can I avoid damaging design? This is a great question, and a common one too. The short answer is: in general writing code that’s easier to test leads to a cleaner design anyway (for example, dependency injection at that appropriate places). If you find you need to rip your design apart to test it, there’s a smell there somewhere - either your design isn’t following SOLID principals, or you’re trying to test the wrong things. Of course, the common example here is testing private methods - how do you test these without exposing secrets? I think for me, if it’s important enough to be tested it’s important enough to be exposed in some way - it might belong in some sort of util or helper (right now I’m not going to go into whether utils or helpers are, in themselves a smell), in a smaller class that only provides this sort of functionality, or simply a protected method. Or, if you’re testing with Groovy, you can access private methods anyway so this becomes a moot point (i.e. your testing framework may be limiting you). In another story from LMAX, we found we had created methods just for testing. It seemed a bit wrong to have these methods only available for testing, but later on down the line, we needed access to many of these methods In Real Life (well, from our Admin app), so our testing had “found” a missing feature. When we came to implement it, it was pretty easy as we’d already done most of it for testing. My co-workers often point to a lack of end-to-end testing as the reason why a lot of bugs get out to production even though they don’t have much unit tests nor integration tests. What, in your experience, is a good balance between unit tests, integration tests and end-to-end testing? Hmm, sounds to me like “lack of tests” is your problem! This is a big (and contentious!) topic. Martin Fowler has written about it, Google wrote something I completely disagree with (so I’m not even going to link to it, but you’ll find references in the links in this paragraph), and my ex-colleague Adrian talks about what we, at LMAX, meant by end-to-end tests. I hope that’s enough to get you started, there’s plenty more out there too. How did you go about getting buy in from the team to use Spock? I cover this in my other presentation on the topic - the short version is, I did a week-long spike to investigate whether Spock would make testing easier for us, showed the pros and cons to the whole team, and then led by example writing tests that (I thought) were more readable than what we had before and, probably most importantly, much easier to write than what we were previously doing. I basically got buy-in by showing how much easier it was for us to use the tool than even JUnit (which we were all familiar with). It did help that we were already using Gradle, so we already had a development dependency on Groovy. It also helped that adding Spock made no changes to the dependencies of the final Jar, which was very important. Over time, further buy-in (certainly from management) came when the new tests started catching more errors - usually regressions in our code or regressions in the server’s overnight builds. I don’t think it was Spock specifically that caught more problems - I think it was writing more tests, and better tests, that caught the issues. Can we do data driven style tests in frameworks like junit or cucumber? I don’t think you can in JUnit (although maybe there’s something out there). I believe someone told me you can do it in TestNG. Are there drawbacks to having tests that only run in ci? I.e I have Java 8 on my machine, but the test requires Java 7 Yes, definitely - the drawback is Time. You have to commit your code to a branch that is being checked by CI and wait for CI to finish before you find the error. In practice, we found very little that was different between Java 7 and 8, for example, but this is a valid concern (otherwise you wouldn’t be testing a complex matrix of dependencies at all). In our case, our Java 6 driver used Netty for async capabilities, as the stuff we were using from Java 7 wasn’t available. This was clearly a different code path that wasn’t tested by us locally as we were all running Java 8. Probably more importantly for us is we were testing against at least 3 different major versions of the server, which all supported different features (and had different APIs). I would often find I’d broken the tests for version 2.2 as I’d only been running it on 2.6, and had forgotten to either turn off the new tests for the old server versions, or didn’t realise the new functionality wouldn’t work there. So the main drawback is time - it takes a lot longer to find out about these errors. There are a few ways to get around this: Commit often!! And to a branch that’s actually going to be run by CI Make your build as fast as possible, so you get failures fast (you should be doing this anyway) You could set up virtual machines locally or somewhere cloudy to run these configurations before committing, but that sounds kinda painful (and to my mind defeats a lot of the point of CI). I set up Travis on my fork of the project, so I could have that running a different version of Java and MongoDB when I committed to my own fork - I’d be able to see some errors before they made it into the “real” project. If you can, you probably want these specific tests run first so they can fail fast. E.g. if you’re running a Java 6 & MongoDB 2.2 configuration on CI, run those tests that only work in that environment first. Would probably need some Gradle magic, and/or might need you to separate these into a different set of folders. The advantage of this approach though is if you set up some aliases on your local machine you could sanity check just these special cases before checking in. For example, I had aliases to start MongoDB versions/configurations from a single command, and to set JAVA_HOME to whichever version I wanted. Do you have any tips for unit tests that pass on dev machines but not on Jenkins because it’s not as powerful as our own machines? E.g. Synchronous calls timeout on the Jenkins builds intermittently. Erk! Yes, not uncommon. No, not really. We had our timeouts set longer than I would have liked to prevent these sorts of errors, and they still intermittently failed. You can also set some sort of retry on the test, and get your build system to re-run those that fail to see if they pass later. It’s kinda nasty though. At LMAX they were able to take testing seriously enough to really invest in their testing architecture, and, of course, this is The Correct Answer. Just often very difficult to sell. If you ask where are tests and dev asks if code is correct? And you say yes. Then dev asks why you’re delaying shipping value, how do you manage that? These are my opinions: Your code is not complete without tests that show me it’s complete. Your code might do what you think it’s supposed to do right now, but given Shared Code Ownership, anyone can come in and change it at any time, you want tests in place to make sure they don’t change it to break what you thought it did The tests are not so much to show it works right now, the tests are to show it continues to work in future Having automated tests will speed you up in future. You can refactor more safely, you can fix bugs and know almost immediately if you broke something, you can read from the test what the author of the code thought the code should do, getting you up to speed faster. You don’t know you’re shipping value without tests - you’re only shipping code (to be honest, you never know if you’re shipping value until much later on when you also analyse if people are even using the feature). Testing almost never slows you down in the long run. Show me the bits of your code base which are poorly tested, and I bet I can show you the bits of your code base that frequently have bugs (either because the code is not really doing what the author thinks, or because subsequent changes break things in subtle ways). If you say code is hard to understand and dev asks if you seriously don’t understand the code, how do you explain you mean easy to understand without thinking rather than ‘can I compile this in my head’? I have zero problem with saying “I’m too stupid to understand this code, and I expect you’re much smarter than me for writing it. Can you please write it in a way so that a less smart person like myself won’t trample all over your beautiful code at a later date through lack of understanding?” By definition, code should be easy to understand by someone who’s not the author. If someone who is not the author says the code is hard to understand, then the code is hard to understand. This is not negotiable. This is what code reviews or pair programming should address. What is effective nagging like? (Whether or not you get what you want) Mmm, good question. Off the top of my head: Don’t make the people who are the target of the nagging feel stupid - they’ll get defensive. If necessary, take the burden of “stupidity” on yourself. E.g. “I’m just not smart enough to be able to tell if this test is failing because the test is bad or because the code is bad. Can you walk me through it and help me fix it?” Do at least your fair share of the work, if not more. When I wanted to get the code to a state where we could fail style errors, I fixed 99% of the problems, and delegated the handful of remaining ones that I just didn’t have the context to fix. In the face of three errors to fix each, the team could hardly say “no” after I’d fixed over 6000. Explain why things need to be done. Developers are adults and don’t want to be treated like children. Give them a good reason and they’ll follow the rules. The few times I didn’t have good reasons, I could not get the team to do what I wanted. Find carrots and sticks that work. At LMAX, a short e-mail at the start of the day summarising the errors that had happened overnight, who seemed to be responsible, and whether they looked like real errors or intermittencies, was enough to get people to fix their problems2 - they didn’t like to look bad, but they also had enough information to get right on it, they didn’t have to wade through all the build info. On occasion, when people were ignoring this, I’d turn up to work with bags of chocolate that I’d bought with my own money, offering chocolate bars to anyone who fixed up the tests. I was random with my carrot offerings so people didn’t game the system. Give up if it’s not working. If you’ve tried to phrase the “why” in a number of ways, if you’ve tried to show examples of the benefits, if you’ve tried to work the results you want into a process, but it’s still not getting done, just accept the fact that this isn’t working for the team. Move on to something else, or find a new angle. 1 I had a colleague at LMAX who was working with a hypothesis that All Private Methods Were Evil - they were clearly only sharable within single class, so provided no reuse elsewhere, and if you have the same bit of code being called multiple times from within the same class (but it’s not valuable elsewhere) then maybe your design is wrong. I’m still pondering this specific hypothesis 4 years on, and I admit I see its pros and cons. 2 This worked so well that this process was automated by one of the guys and turned into a tool called AutoTrish, which as far as I know is still used at LMAX. Dave Farley talks about it in some of hisContinuous Delivery talks. Resources My talk that specifically looks at the advantages of Spock over JUnit, plus some Spock-specific resources. I love Jay Fields book Working Effectively With Unit Tests - if I could have made the whole team read this before moving to Spock, we might have stuck with JUnit. Go read everything Adrian Sutton has written about testing at LMAX. If not everything, definitely Abstraction by DSL and Making End-to-End Tests Work If you can’t make it all the way through Dave Farley and Jez Humble’s excellent Continuous Delivery book, do take a look at one of Dave’s presentations on the subject, for example The Rationale for Continuous Delivery or The Process, Technology and Practice of Continuous Delivery - my own talk was around testing, but I’m working off the assumption that you’re at least running some sort of Continuous Integration, if not Continuous Delivery. Martin Fowler has loads of interesting and useful articles on testing. Abstract What can you do to help developers a) write tests b) write meaningful tests and c) write readable tests? Trisha will talk about her experiences of working in a team that wanted to build quality into their new software version without a painful overhead - without a QA / Testing team, without putting in place any formal processes, without slavishly improving the coverage percentage. The team had been writing automated tests and running them in a continuous integration environment, but they were simply writing tests as another tick box to check, there to verify the developer had done what the developer had aimed to do. The team needed to move to a model where tests provided more than this. The tests needed to: Demonstrate that the library code was meeting the requirements Document in a readable fashion what those requirements were, and what should happen under non-happy-path situations Provide enough coverage so a developer could confidently refactor the code This talk will cover how the team selected a new testing framework (Spock, a framework written in Groovy that can be used to test JVM code) to aid with this effort, and how they evaluated whether this tool would meet the team’s needs. And now, two years after starting to use Spock, Trisha can talk about how both the tool and the shift in the focus of the purpose of tests has affected the quality of the code. And, interestingly, the happiness of the developers.

That Supplier is Better For You Since releasing the 2015 State of the Software Supply Chain Report, there has been a lot of great discussion across the industry on best practices for managing the complexity introduced by the volume and velocity of the components used across your software supply chain. Today I want to focus on the huge ecosystem of open source projects (“suppliers”) that feed a steady stream of innovative components into our software supply chains. In the Java ecosystem alone, there are now over 108,000 suppliers of open source components. Across all component types available to developers (e.g., RubyGems, NuGet, npm, Bower, PyPI, etc.), estimates now reach over 650,000 suppliers of open source projects. Source: ModuleCounts.com However, like in traditional manufacturing, not all suppliers deliver parts of comparable quality and integrity. My latest research, the 2015 State of the Software Supply Chain Report, shows that some open source projects use restrictive licenses and vulnerable sub-components, while other projects are far more diligent at updating the overall quality of their components. Choosing the best and fewest suppliers can improve the quality and integrity of the applications we deliver to our customers. While I am hosting a webinar next week to share many of the detailed report findings, I wanted to share a few of the more meaningful stats here. Your 7,600 Suppliers My research for the report revealed many new perspectives on “suppliers” across the software supply chains. First of all, I saw that the average large development organization consumed over 240,000 open source components last year — sourced from over 7,600 open source projects. Average number of open source component downloads per organization in calendar 2014 On the surface, the huge reliance on open source projects is a great thing. Development teams have chosen to not write those pieces themselves, but have sourced the needed components from outside suppliers. This practice speeds development, enables more innovation, and ensures time-to-release goals are achieved. The use of open source is so prolific today, few of us could ever imagine reducing the use of those components and their suppliers in the future. At the same time that we benefit from open source, our high paced, high volume consumption practices don’t allow us the time needed to do the due diligence on the suppliers or open source projects where we source our component parts from. Average number of known vulnerabilities downloaded by organization in calendar 2014. For example, of the 240,000 average component downloads in 2014, the same businesses sourced an average of 15,000 components that included known security vulnerabilities. In many cases, developers were downloading vulnerable component versions, when safer versions of those same components were available from the open source projects. While no one intends to download components with known vulnerabilities, the problem is exacerbated due to the lack the visibility into a better recommended version. Fewer Suppliers, Less Context Switching Choosing an open source project supplier should be considered an important strategic decision in organizations because changing a supplier (“open source project”) used is far more effort than swapping out a specific component. Like traditional suppliers, open source projects have good and bad practices impacting the overall quality of their component parts. Traditional manufacturing supply chains intentionally select specific parts from approved suppliers. They also rely on formalized sourcing and procurement practices. This practice also focuses the organization on using the best and fewest suppliers — an effort that improves quality, reduces context switching, and also accelerates mean time to repair when defects are discovered. One industry example from the report describes how Toyota manages 125 suppliers for their Prius to help sustain competitive advantages over GM who manages over 800 suppliers for the Chevy Volt. By contrast, development teams working with software supply chains often rely on an unchecked variety of supply, where each developer or development team can make their own sourcing and procurement decisions. The effort of managing over 7,600 suppliers introduces a drag on development and is contrary to their need to develop faster as part of agile, continuous delivery and devops practices. Coming to Terms When you come to terms with the volume of consumption and the massive ecosystem of suppliers you can source your components from, you quickly realize it is impossible to address this issue with a manual review process. Any organizations clutching to these outdated manual practices are will continue to be outgunned by the velocity by their software supply chains. Just as traditional manufacturing supply chains have turned to automation, software development teams need to take the same approach by further automating their software supply chains. Information about suppliers and the quality of their projects needs to be made available to developers at the time they are selecting components. Information about the latest versions, features, licenses, known vulnerabilities, popularity of versions being used, and the cadence of new releases should be made available to developers in an automated way. Automating the availability of this information about suppliers can lead to better and fewer suppliers being used. Be sure to read the full 2015 State of the Software Supply Chain Report for more information about open source suppliers and organizations sourcing practices. The report also highlights current and best practices being used in organizations that are managing their use of suppliers that feed their software supply chains.

In this post, I demonstrate one approach for generating JSON Schema from an XML Schema (XSD). While providing an overview of an approach for creating JSON Schema from XML Schema, this post also demonstrates use of a JAXB implementation (xjc version 2.2.12-b150331.1824 bundled with JDK 9 [build 1.9.0-ea-b68]) and of a JSON/Java binding implementation (Jackson 2.5.4). The steps of this approach for generating JSON Schema from an XSD can be summarized as: Apply JAXB's xjc compiler to generate Java classes from XML Schema (XSD). Apply Jackson to generate JSON schema from JAXB-generated Java classes. Generating Java Classes from XSD with JAXB's xjc For purposes of this discussion, I'll be using the simple Food.xsd used in my previous blog post A JAXB Nuance: String Versus Enum from Enumerated Restricted XSD String. For convenience, I have reproduced that simple schema here without the XML comments specific to that earlier blog post: Food.xsd It is easy to use the xjc command line tool provided by the JDK-provided JAXB implementation to generate Java classes corresponding to this XSD. The next screen snapshot shows this process using the command: xjc -d jaxb .\Food.xsd This simple command generates Java classes corresponding to the provided Food.xsd and places those classes in the specified "jaxb" subdirectory. Generating JSON from JAXB-Generated Classes with Jackson With the JAXB-generated classes now available, Jackson can be applied to these classes to generate JSON from the Java classes. Jackson is described on its main portal page as "a multi-purpose Java library for processing" that is "inspired by the quality and variety of XML tooling available for the Java platform." The existence of Jackson and similar frameworks and libraries appears to be one of the reasons that Oracle hasdropped the JEP 198 ("Light-Weight JSON API") from Java SE 9. [It's worth noting that Java EE 7 already hasbuilt-in JSON support with its implementation of JSR 353 ("Java API for JSON Processing"), which is not associated with JEP 198).] One of the first steps of applying Jackson to generating JSON from our JAXB-generated Java classes is to acquire and configure an instance of Jackson's ObjectMapper class. One approach for accomplishing this is shown in the next code listing. Acquiring and Configuring Jackson ObjectMapper for JAXB Serialization/Deserialization /** * Create instance of ObjectMapper with JAXB introspector * and default type factory. * * @return Instance of ObjectMapper with JAXB introspector * and default type factory. */ private ObjectMapper createJaxbObjectMapper() { final ObjectMapper mapper = new ObjectMapper(); final TypeFactory typeFactory = TypeFactory.defaultInstance(); final AnnotationIntrospector introspector = new JaxbAnnotationIntrospector(typeFactory); // make deserializer use JAXB annotations (only) mapper.getDeserializationConfig().with(introspector); // make serializer use JAXB annotations (only) mapper.getSerializationConfig().with(introspector); return mapper; } The above code listing demonstrates acquiring the Jackson ObjectMapper instance and configuring it to use a default type factory and a JAXB-oriented annotation introspector. With the Jackson ObjectMapper instantiated and appropriately configured, it's easy to use thatObjectMapper instance to generate JSON from the generated JAXB classes. One way to accomplish this using the deprecated Jackson class JsonSchema is demonstrated in the next code listing. Generating JSON from Java Classes with Deprecated com.fasterxml.jackson.databind.jsonschema.JsonSchema Class /** * Write JSON Schema to standard output based upon Java source * code in class whose fully qualified package and class name * have been provided. * * @param mapper Instance of ObjectMapper from which to * invoke JSON schema generation. * @param fullyQualifiedClassName Name of Java class upon * which JSON Schema will be extracted. */ private void writeToStandardOutputWithDeprecatedJsonSchema( final ObjectMapper mapper, final String fullyQualifiedClassName) { try { final JsonSchema jsonSchema = mapper.generateJsonSchema(Class.forName(fullyQualifiedClassName)); out.println(jsonSchema); } catch (ClassNotFoundException cnfEx) { err.println("Unable to find class " + fullyQualifiedClassName); } catch (JsonMappingException jsonEx) { err.println("Unable to map JSON: " + jsonEx); } } The code in the above listing instantiates acquires the class definition of the provided Java class (the highest level Food class generated by the JAXB xjc compiler in my example) and passes that reference to the JAXB-generated class to ObjectMapper's generateJsonSchema(Class) method. The deprecated JsonSchemaclass's toString() implementation is very useful and makes it easy to write out the JSON generated from the JAXB-generated classes. For purposes of this demonstration, I provide the demonstration driver as a main(String[]) function. That function and the entire class to this point (including methods shown above) is provided in the next code listing. JsonGenerationFromJaxbClasses.java, Version 1 package dustin.examples.jackson; import com.fasterxml.jackson.databind.AnnotationIntrospector; import com.fasterxml.jackson.databind.JsonMappingException; import com.fasterxml.jackson.databind.ObjectMapper; import com.fasterxml.jackson.databind.type.TypeFactory; import com.fasterxml.jackson.module.jaxb.JaxbAnnotationIntrospector; import com.fasterxml.jackson.databind.jsonschema.JsonSchema; import static java.lang.System.out; import static java.lang.System.err; /** * Generates JavaScript Object Notation (JSON) from Java classes * with Java API for XML Binding (JAXB) annotations. */ public class JsonGenerationFromJaxbClasses { /** * Create instance of ObjectMapper with JAXB introspector * and default type factory. * * @return Instance of ObjectMapper with JAXB introspector * and default type factory. */ private ObjectMapper createJaxbObjectMapper() { final ObjectMapper mapper = new ObjectMapper(); final TypeFactory typeFactory = TypeFactory.defaultInstance(); final AnnotationIntrospector introspector = new JaxbAnnotationIntrospector(typeFactory); // make deserializer use JAXB annotations (only) mapper.getDeserializationConfig().with(introspector); // make serializer use JAXB annotations (only) mapper.getSerializationConfig().with(introspector); return mapper; } /** * Write out JSON Schema based upon Java source code in * class whose fully qualified package and class name have * been provided. * * @param mapper Instance of ObjectMapper from which to * invoke JSON schema generation. * @param fullyQualifiedClassName Name of Java class upon * which JSON Schema will be extracted. */ private void writeToStandardOutputWithDeprecatedJsonSchema( final ObjectMapper mapper, final String fullyQualifiedClassName) { try { final JsonSchema jsonSchema = mapper.generateJsonSchema(Class.forName(fullyQualifiedClassName)); out.println(jsonSchema); } catch (ClassNotFoundException cnfEx) { err.println("Unable to find class " + fullyQualifiedClassName); } catch (JsonMappingException jsonEx) { err.println("Unable to map JSON: " + jsonEx); } } /** * Accepts the fully qualified (full package) name of a * Java class with JAXB annotations that will be used to * generate a JSON schema. * * @param arguments One argument expected: fully qualified * package and class name of Java class with JAXB * annotations. */ public static void main(final String[] arguments) { if (arguments.length < 1) { err.println("Need to provide the fully qualified name of the highest-level Java class with JAXB annotations."); System.exit(-1); } final JsonGenerationFromJaxbClasses instance = new JsonGenerationFromJaxbClasses(); final String fullyQualifiedClassName = arguments[0]; final ObjectMapper objectMapper = instance.createJaxbObjectMapper(); instance.writeToStandardOutputWithDeprecatedJsonSchema(objectMapper, fullyQualifiedClassName); } } To run this relatively generic code against the Java classes generated by JAXB's xjc based upon Food.xsd, I need to provide the fully qualified package name and class name of the highest-level generated class. In this case, that's com.blogspot.marxsoftware.foodxml.Food (package name is based on the XSD's namespace because I did not explicitly override that when running xjc). When I run the above code with that fully qualified class name and with the JAXB classes and Jackson libraries on the classpath, I see the following JSON written to standard output. Generated JSON {"type":"object","properties":{"vegetable":{"type":"string","enum":["CARROT","SQUASH","SPINACH","CELERY"]},"fruit":{"type":"string"},"dessert":{"type":"string","enum":["PIE","CAKE","ICE_CREAM"]}} Humans (which includes many developers) prefer prettier print than what was just shown for the generated JSON. We can tweak the implementation of the demonstration class's methodwriteToStandardOutputWithDeprecatedJsonSchema(ObjectMapper, String) as shown below to write out indented JSON that better reflects its hierarchical nature. This modified method is shown next. Modified writeToStandardOutputWithDeprecatedJsonSchema(ObjectMapper, String) to Write Indented JSON /** * Write out indented JSON Schema based upon Java source * code in class whose fully qualified package and class * name have been provided. * * @param mapper Instance of ObjectMapper from which to * invoke JSON schema generation. * @param fullyQualifiedClassName Name of Java class upon * which JSON Schema will be extracted. */ private void writeToStandardOutputWithDeprecatedJsonSchema( final ObjectMapper mapper, final String fullyQualifiedClassName) { try { final JsonSchema jsonSchema = mapper.generateJsonSchema(Class.forName(fullyQualifiedClassName)); out.println(mapper.writerWithDefaultPrettyPrinter().writeValueAsString(jsonSchema)); } catch (ClassNotFoundException cnfEx) { err.println("Unable to find class " + fullyQualifiedClassName); } catch (JsonMappingException jsonEx) { err.println("Unable to map JSON: " + jsonEx); } catch (JsonProcessingException jsonEx) { err.println("Unable to process JSON: " + jsonEx); } } When I run the demonstration class again with this modified method, the JSON output is more aesthetically pleasing: Generated JSON with Indentation Communicating Hierarchy { "type" : "object", "properties" : { "vegetable" : { "type" : "string", "enum" : [ "CARROT", "SQUASH", "SPINACH", "CELERY" ] }, "fruit" : { "type" : "string" }, "dessert" : { "type" : "string", "enum" : [ "PIE", "CAKE", "ICE_CREAM" ] } } } I have been using Jackson 2.5.4 in this post. The classcom.fasterxml.jackson.databind.jsonschema.JsonSchema is deprecated in that version with the comment, "Since 2.2, we recommend use of external JSON Schema generator module." Given that, I now look at using the new preferred approach (Jackson JSON Schema Module approach). The most significant change is to use the JsonSchema class in the com.fasterxml.jackson.module.jsonSchemapackage rather than using the JsonSchema class in the com.fasterxml.jackson.databind.jsonschema package. The approaches for obtaining instances of these different versions of JsonSchema classes are also different. The next code listing demonstrates using the newer, preferred approach for generating JSON from Java classes. Using Jackson's Newer and Preferred com.fasterxml.jackson.module.jsonSchema.JsonSchema /** * Write out JSON Schema based upon Java source code in * class whose fully qualified package and class name have * been provided. This method uses the newer module JsonSchema * class that replaces the deprecated databind JsonSchema. * * @param fullyQualifiedClassName Name of Java class upon * which JSON Schema will be extracted. */ private void writeToStandardOutputWithModuleJsonSchema( final String fullyQualifiedClassName) { final SchemaFactoryWrapper visitor = new SchemaFactoryWrapper(); final ObjectMapper mapper = new ObjectMapper(); try { mapper.acceptJsonFormatVisitor(mapper.constructType(Class.forName(fullyQualifiedClassName)), visitor); final com.fasterxml.jackson.module.jsonSchema.JsonSchema jsonSchema = visitor.finalSchema(); out.println(mapper.writerWithDefaultPrettyPrinter().writeValueAsString(jsonSchema)); } catch (ClassNotFoundException cnfEx) { err.println("Unable to find class " + fullyQualifiedClassName); } catch (JsonMappingException jsonEx) { err.println("Unable to map JSON: " + jsonEx); } catch (JsonProcessingException jsonEx) { err.println("Unable to process JSON: " + jsonEx); } } The following table compares usage of the two Jackson JsonSchema classes side-by-side with the deprecated approach shown earlier on the left (adapted a bit for this comparison) and the recommended newer approach on the right. Both generate the same output for the same given Java class from which JSON is to be written. /** * Write out JSON Schema based upon Java source code in * class whose fully qualified package and class name have * been provided. This method uses the deprecated JsonSchema * class in the "databind.jsonschema" package * {@see com.fasterxml.jackson.databind.jsonschema}. * * @param fullyQualifiedClassName Name of Java class upon * which JSON Schema will be extracted. */ private void writeToStandardOutputWithDeprecatedDatabindJsonSchema( final String fullyQualifiedClassName) { final ObjectMapper mapper = new ObjectMapper(); try { final com.fasterxml.jackson.databind.jsonschema.JsonSchema jsonSchema = mapper.generateJsonSchema(Class.forName(fullyQualifiedClassName)); out.println(mapper.writerWithDefaultPrettyPrinter().writeValueAsString(jsonSchema)); } catch (ClassNotFoundException cnfEx) { err.println("Unable to find class " + fullyQualifiedClassName); } catch (JsonMappingException jsonEx) { err.println("Unable to map JSON: " + jsonEx); } catch (JsonProcessingException jsonEx) { err.println("Unable to process JSON: " + jsonEx); } } /** * Write out JSON Schema based upon Java source code in * class whose fully qualified package and class name have * been provided. This method uses the newer module JsonSchema * class that replaces the deprecated databind JsonSchema. * * @param fullyQualifiedClassName Name of Java class upon * which JSON Schema will be extracted. */ private void writeToStandardOutputWithModuleJsonSchema( final String fullyQualifiedClassName) { final SchemaFactoryWrapper visitor = new SchemaFactoryWrapper(); final ObjectMapper mapper = new ObjectMapper(); try { mapper.acceptJsonFormatVisitor(mapper.constructType(Class.forName(fullyQualifiedClassName)), visitor); final com.fasterxml.jackson.module.jsonSchema.JsonSchema jsonSchema = visitor.finalSchema(); out.println(mapper.writerWithDefaultPrettyPrinter().writeValueAsString(jsonSchema)); } catch (ClassNotFoundException cnfEx) { err.println("Unable to find class " + fullyQualifiedClassName); } catch (JsonMappingException jsonEx) { err.println("Unable to map JSON: " + jsonEx); } catch (JsonProcessingException jsonEx) { err.println("Unable to process JSON: " + jsonEx); } } This blog post has shown two approaches using different versions of classes with name JsonSchema provided by Jackson to write JSON based on Java classes generated from an XSD with JAXB's xjc. The overall process demonstrated in this post is one approach for generating JSON Schema from XML Schema.

You are working on a big project, developing rules, events and processes at your enterprise for mission critical business needs. Part of the requirements state that a certain business unit will be providing their data model for you to leverage. This data model will not be designed in the JBoss BPM Suite Data Modeler but you need to have access to it while working on your rules, events and processes from the business central dashboard. For this article we will be using the JBoss BPM Travel Agency demo project as a reference, with it's current data model built externally to the JBoss BPM Suite business central. The external data model is called the acme-data-model and is found in the project directory: This data model is built during installation and provides you with an object data model as a Java Archive (JAR) file which is installed into the JBoss BPM Suite business central component by placing it into the following location: jboss-eap-6.4/standalone/deployments/business-central.war/WEB_INF/lib/acmeDataModel-1.0.jar Authoring --> Artifact repository. This way of deploying the data model means that it is available to all projects you work on in JBoss BPM Suite business central, something that might not always be preferable. What we need is a way to deploy external data models into JBoss BPM Suite and then selectively add them to projects as needed. Within JBoss BPM Suite there is an Artifact Repository that is made just for this purpose. We can upload through the business central dashboard UI all our models and then pick and choose from the repository artifacts (your data model is one artifact) on a per project basis. This gives you absolute control over the models that a project can access. Choose external data model file. There are a few steps involved that we will take you through here to change the current installation of JBoss BPM Travel Agency where the acmeDataModel-1.0.jar file will be removed from the previously mentioned business central component and uploaded into the Artifact Repository and added to the Special Trips Agency project. Here is how you can do it yourself: obtain and install JBoss BPM Travel Agency demo project remove current data model from global business central application: $ rm ./target/jboss-eap-6.4/standalone/deployments/business-central.war/WEB_INF/lib/acmeDataModel-1.0.jar Upload external model jar file. start JBoss BPM Suite server after installation as stated in the installation instructions login to JBoss BPM Suite at http://localhost:8080/business-centralwith: u: erics p: bpmsuite1! go to AUTHORING --> ARTIFACT REPOSITORY go to UPLOAD --> CHOOSE FILE... --> projects/acme-data-model/target/acmeDataModel-1.0.jar --> click button to UPLOAD this puts the external data model into the JBoss BPM Suite artifact repository Select dependencies to add to project. got to AUTHORING --> PROJECT AUTHORING --> OPEN PROJECT EDITOR in project editor select GENERAL PROJECT SETTINGS --> DEPENDENCIES in dependencies select ADD FROM REPOSITORY -> in pop-upSELECT entry acmeDataModel-1.0.jar This will result in the external data model being added only to the Special Trips Agency project and not available to other projects unless they add this same dependency from the JBoss BPM Suite artifact repository. If you build & deploy the project, run it as described in the project instructions you will find that the external data model is available and used by the various rules and process components that are the JBoss BPM Travel Agency. As a closing note, this works exactly the same for JBoss BRMS projects.

What is a Leap Second? As some know - there will be a new leap second at the end of this month. Leap seconds are inserted into the standard UTC time scale by help of label "60" either at the end of June or December (exceptionally also in March and September) in irregular intervals in order to compensate for the slightly increasing difference between an astronomical day and the pulse of modern atomic clocks we now use for time-keeping. Initial Situation When I asked myself in year 2012 (where the last leap second happened) how to watch it using Java-based software the answer was simply: Not possible. At least not possible with any kind of standard tool. As with most software today, Java is totally ignorant towards leap seconds and pretends that they don't exist. There is no way to let Java print timestamps like "2015-06-30T23:59:60Z". Note that Java-8 with its new time library (JSR-310, java.time-package) does not offer this feature, too. For standard business purposes this approach is fine. From a scientific point of view however, this is not satisfying. Of course, these rare leap seconds still exist. When it comes to clock synchronization even leap-second-ignorant software has to pay some attribution if monotonicity is important. Any clock will sooner or later be synchronized such that leap seconds will be taken into account, often by setting the clock one second back. NTP time servers will usually repeat the timestamp "2015-06-30T23:59:59Z" and send in advance a so called leap indicator flag. This flag does not directly indicate the current timestamp as leap second but is only intended to be an announcement flag. So even NTP tries to hide leap seconds in some way. And some NTP servers like those from Google apply internal smearing algorithms (by slightly prolonging the second over a day) in order to avoid reporting any leap second at all. Decision for a New Library So I decided to develop a new time library named Time4J to solve this issue. First I had to set up a new infrastructure around a built-in configurable leap second table, then a new class net.time4j.Moment capable of holding a leap second as internal state. A SNTP-based clock yielding Moment-timestamps was developed and successfully tested during the last leap second in 2012. Since leap seconds are also reported by the well-known IANA-TZDB (standard timezone repository) I decided to develop a mechanism to apply the whole TZDB and its leap seconds on the class net.time4j.Moment. Finally I had even set up a new format and parse engine from the scratch to enable formatting and parsing of leap seconds in any timezone. A lot of work but the existing Java-software was not useable at all, not even as starting point. Recently I also developed a monotonic clock which enables to watch a leap second offline. Keep in mind that any clock - even NTP - are no reliable sources to watch a leap second in live connection. Fortunately Java offers at least System.nanoTime() which accesses the monotonic clock of operating system (if available). So I used this as a base of the new monotonic clock of Time4J which can connect to a NTP time server before a leap second will happen. How Does Time4J Help? import net.time4j.Moment; import net.time4j.Month; import net.time4j.PlainDate; import net.time4j.SI; import net.time4j.SystemClock; import net.time4j.base.TimeSource; import net.time4j.clock.FixedClock; import net.time4j.format.expert.ChronoFormatter; import net.time4j.format.expert.PatternType; import net.time4j.tz.olson.AMERICA; import java.util.Locale; import java.util.concurrent.ScheduledFuture; import java.util.concurrent.ScheduledThreadPoolExecutor; import java.util.concurrent.TimeUnit; public class DZone { static TimeSource clock; static ScheduledThreadPoolExecutor executor; static ScheduledFuture future; public static void main(String[] args) throws Exception { // when is the next leap second? Moment ls = SystemClock.currentMoment().with(Moment.nextLeapSecond()); if (ls == null) { // ooops, we are now too late and after last known leap second, // so let us set it directly ls = PlainDate.of(2015, Month.JUNE, 30).atTime(23, 59, 59) .atUTC().plus(1, SI.SECONDS); } // move 5 seconds earlier ls = ls.minus(5, SI.SECONDS); // let's start our monotonic clock at determined fixed time clock = SystemClock.MONOTONIC.synchronizedWith(FixedClock.of(ls)); // finally we observe our clock every second for 10 times executor = new ScheduledThreadPoolExecutor(15); future = executor.scheduleAtFixedRate( new ClockTask(), 0, 1, TimeUnit.SECONDS); } static class ClockTask implements Runnable { private int attempt = 1; public void run() { Moment moment = clock.currentTime(); String time = ChronoFormatter.ofMomentPattern( "MMM/dd/uuuu hh:mm:ss a XXX", PatternType.CLDR, Locale.ENGLISH, AMERICA.NEW_YORK ).format(moment); String flag = moment.isLeapSecond() ? " [leap second]" : ""; System.out.println(time + flag); attempt++; if (attempt > 10) { future.cancel(false); } } } } /* output: Jun/30/2015 07:59:55 PM -04:00 Jun/30/2015 07:59:56 PM -04:00 Jun/30/2015 07:59:57 PM -04:00 Jun/30/2015 07:59:58 PM -04:00 Jun/30/2015 07:59:59 PM -04:00 Jun/30/2015 07:59:60 PM -04:00 [leap second] Jun/30/2015 08:00:00 PM -04:00 Jun/30/2015 08:00:01 PM -04:00 Jun/30/2015 08:00:02 PM -04:00 Jun/30/2015 08:00:03 PM -04:00 */ For a real-life scenario you can just replace the clock this way (SNTP-example): SntpConnector sntp = new SntpConnector("ptbtime1.ptb.de"); sntp.connect(); clock = sntp; Conclusion Time4J does not try to hide the reality but gives you also the freedom to decide if you want to handle leap seconds or not. You can even switch off this feature completely by setting an appropriate system property. As side effect, a library has been developed which does not need to be afraid of any comparison with other existing libraries like JSR-310 (java.time-package in Java-8) or Joda-Time.

Written by Craig Wentworth. To understand the furor that’s greeted recent vendor announcements around open source analytics computing engine Spark, and some commentary seemingly setting up a Spark versus Hadoop battle, it’s worth taking a moment to recap on what each actually is (and is not). As I covered in last year’s MWD report on Hadoop and its family of tools, when people talk about Apache Hadoop they’re often referring to a whole framework of tools designed to facilitate distributed parallel processing of large datasets. That processing was traditionally confined to MapReduce batch jobs in Hadoop’s early days, though Hadoop 2 brought the YARN resource scheduler and opened up Hadoop to streaming, real-time querying and a wider array of analytical programming applications (beyond MapReduce). Spark has been designed to run on top of Hadoop’s Distributed File System (amongst other data platforms) as an alternative to MapReduce – tuned for real-time streaming data processing and fast interactive queries, and with multi-genre analytics applicability (machine learning, time series, graph, SQL, streaming out-of-the-box). It gets that speed advantage by caching in-memory (rather than writing interim results to disk, as MapReduce does), but with that approach comes a need for higher-spec physical machines (compared with MapReduce’s tolerance for commodity hardware). So, Spark isn’t about to replace Hadoop -- but it may well supplant MapReduce (especially in growing real-time use cases). Those “Spark vs Hadoop” headlines are about as meaningful as one proclaiming “mushrooms vs pizza." Yes, mushroom might be a more suitable topping than, say, pepperoni (especially in a vegetarian use case), but it’ll still be deployed on the same dough and tomato sauce pizza platform. Nobody’s about to suggest the mushroom should go it alone! But what’s behind the headlines and the hype is a story of enterprise adoption – or at least vendors anticipating that adoption and investing in ‘the weaponization of Spark’ as it faces the more exacting standards of security, scaling performance, consistency, etc. which come with mainstream enterprise deployment. Big names like IBM, Databricks (the company formed by the originators of Spark), and MapR made commitments in and around the Spark Summit earlier this month. MapR has announced three new Quick Start Solutions for its Hadoop distribution to help customers get started with Spark in real-time security log analytics, genome sequencing, and time series analytics; Databricks’ cloud-hosted Spark platform (formerly known as Databricks Cloud) has become generally available; and IBM announced a raft of measures designed to give Spark a significant shot in the arm – it’s open sourcing its SystemML technology to bolster Spark’s machine learning capabilities, integrating Spark into its own analytics platforms, investing in Spark training and education, committing 3,500 of its researchers and developers to work on Spark-related projects, and offering Spark as a service on its Bluemix developer cloud. Given the overlap with Databricks’ business model (of offering development, certification, and support for Spark), IBM’s intentions are likely to tread on some toes before long – but for now, at least, both companies are content to focus on the combined push benefiting the Spark community and its enterprise aspirations overall (though clearly IBM’s betting on all this investment buying it some influence over where Spark goes next). It’s worth bearing in mind that not all its supporters champion Spark wholesale and all the interested parties tend to be interested in particular bits of Spark (as wide-ranging as it is) because of overlaps with their own preferred toolsets. For instance, although Spark supports many analytics genres, Cloudera focuses on its machine learning capabilities (as it has its own SQL-on-Hadoop tool in Impala), and MapR and Hortonworks also promote Drill and Hive as their favoured source of SQL-on-Hadoop. IBM’s support is focused on Spark’s machine learning and in-memory capabilities (hence the SystemML open sourcing news). In the face of such strong vendor preferences, how long before some of Spark’s current features fall away (or at least start to show the effects of being starved of as much care and feeding as is bestowed upon vendors’ favourite Spark components)? The Spark community is at much the same place the Hadoop one was at a while back – it’s showing great promise and suitability in key growth workloads (in Spark’s case, such as real-time IoT applications). However, the product as it stands is too immature for many enterprise tastes. Cue enterprise software vendors stepping up to help grow Spark up fast. Their challenge though is to smooth out the edges without smothering what made it so interesting in the first place.

When a team works with a lot of maven projects it becomes quickly painful to do some basic tasks like: manage versionning and connections between the different projects. releasing and opening versions, especially when the maven-release plugin needs to be run on many projects and when versionning is not standard. managing external dependencies also can become complex, and ensuring that a single version of a dependency is used accross different projects is sometimes not a trivial question to ask. in a one word, applying transformations on a dependency graph is difficult. mind-mapping the dependency graph is difficult when the number of projects grows. That can increase the amount of time needed by new people to understand a project graph, and that also makes maintaining and changing things difficult. checking consistency and optimizing the dependency graph is not an easy task neither. having an always up-to-date build of snapshots and release is not easy when projects are distributed everywhere. Pom Explorer So there is the Pom Explorer tool which tries to address those problems by providing those functionalities : release a graph : release a pom or all poms and its/theirs dependencies and updates all dependent poms accross multiple repositories and projects, change a gav : updates a project’s gav and make all the project which depends on it follow this change. manages properties, dependency management, and so on. Pom-explorer knows what pom.xml to update and where to update. If a dependency specifies ${foobar.version}, pom-explorer will go to update the foobar.version property. query the dependency graph to retrieve pertinent information about your projects, statistics and check functions are also available, display 3d interactive graph, export graphml files, find not used dependencies and other similar problems, list java classes provided by artifacts, list java classes referenced by artifacts, runs a light and efficient web server so local and shared usage is possible. The tool will also support automatically building projects in order to always have such or such project always up to date. Use cases In this article, I will show some common use cases possible with this tool. Installation First one needs to install and run the software. Put yourself in a temporary directory and type those commands : git clone https://github.com/ltearno/pom-explorer.git cd pom-explorer java -jar target/pom-explorer.jar The program should welcome you and ask you to go to this address : http://localhost:90 This is the console to the application. You can type commands in the prompt, they will be sent to the server and it will answer. You can use up and down arrows to recall past commands. Let’s start by typing ? to get the available commands : Analyze of repositories OK. First we will analyse a directory where there are many maven projects, then we will work a bit to optimize those projects. You will have to adapt the exercise to your computer. Let’s analyse my git repositories directory : analyze directory c:\documents\repos This will analyze my projects and construct an in-memory graph of the dependency graph : Now, the program knows about everything on my projects, let’s start asking questions ! List of GAVs… Let’s get the list of all existing GAVs (groupId, artifactId, version) in the graph. There will be my projects and all the GAVs on which they depend. Type this command : gav li Note that you can type only the first letters of a command, as long as there is no ambiguity. Here li stands for list. Find dependencies on an obsolete artifact As I look through the list of GAVs, I remark that there are still an old snapshot version of the hexa.binding artifact hanging around. The latest released version is 1.3 and the working version is 1.4-SNAPSHOT so the version 1.3-SNAPSHOTshould not be used anymore. Which is the project still depending on this very deprecated this version ? Let’s ask the question : depends on fr.lteconsulting:hexa.binding:1.3-SNAPSHOT Here it is ! the project rigpa.org:regsys-clients:1.0.0-SNAPSHOT is still using an old snapshot. Let’s arrange that. Pom Explorer is able to change the pom properties and dependencies by itself. Updating this wrong dependency What we want is to change fr.lteconsulting:hexa.binding:1.3-SNAPSHOT tofr.lteconsulting:hexa.binding:1.3 so that the project uses the latest release available. We could desire to change for fr.lteconsulting:hexa.binding:1.4-SNAPSHOT which would be possible with the same command as we’ll see. For that we will use the change gav command : cha ga fr.lteconsulting:hexa.binding:1.3-SNAPSHOT fr.lteconsulting:hexa.binding:1.3 Here is what Pom Explorer answers : So first Pom Explorer finds what needs to be changed in the graph. This might be the project itself and all projects which depend on it. After that the program begins a loop in which all changes are checked and appropriately transformed when needed. For instance changing a dependency version can become changing a property value. Changes are first resolved as described before and they are then transformed in a change list to apply to be applied to pom.xml files. In the ouput, there is first a little warning saying thefr.lteconsulting:hexa.binding:1.3-SNAPSHOT project was not found. That’s normal because the project in now in version 1.4-SNAPSHOT. So there is no need to modify it. Then in the change list section, the changes that are to be applied to pom.xml files are listed. The first one says ‘project not found’ and that’s ok as seen before. The second one says to modify the C:\documents\repos\regsys-clients\pom.xmland change the dependency ([DEPENDENCY])fr.lteconsulting:hexa.binding:1.3-SNAPSHOT tofr.lteconsulting:hexa.binding:1.3. The “causes” message is useful when a change is caused by other changes (as said before a dependency change can become one or several property changes). If we had properties involved, Pom Explorer would have found them and included them in the change set. Now that we reviewed the proposed changes and agreed with them, let’s apply them by using the same command with the -apply flag : cha ga fr.lteconsulting:hexa.binding:1.3-SNAPSHOT fr.lteconsulting:hexa.binding:1.3 -apply We see that at the end of the same process, the program updated the dependency in the right pom.xml file. Let’s have a look at the file it self : fr.lteconsulting hexa.binding 1.3 compile OK, the file is correct now… Oh well no ! I just find other dependencies in SNAPSHOT versions ! Finding more duplicate and obsolete dependencies Let’s accept it, our projects are not up to date. Well let’s see how many of those artifacts there are with multiple versions used. For that i type the checkcommand : Ok there is some work to do ! Opening a version Now let’s look at another use case. Say that the hexa.binding project is in version 1.3 and i want to open the version 1.4-SNAPSHOT. I also want all the projects which depend on version 1.3to move to 1.4-SNAPSHOT. On the way, I want all modified projects still in a release version to be SNAPSHOT-ized too. And i want this to happen recursively as new projects are opened. With Pom Explorer, that’s only one command : change gav fr.lteconsulting:hexa.binding:1.3 fr.lteconsulting:hexa.binding:1.4-SNAPSHOT As you can see, warnings are generated when projects are reopened : Those are normal warnings, they are just here so that you know what happens. Then, there is a big list of changes to be made, because the hexa.bindingartifact is used in many central projects that were in a release state. Glad that we didn’t do that by hand ! Even with the maven-update-version plugin, there would have been a lot of repositories to go to open and update. Let’s apply the changes with the -apply flag : cha ga fr.lteconsulting:hexa.binding:1.3 fr.lteconsulting:hexa.binding:1.4-SNAPSHOT -apply All the changes have been made, about 30 of them. In one go ! Refresh the page so that a new session is created from the changed files. We can see that many of the projects have been reopened : You now have to commit all the repositories with this update. Pom explorer does not do that yet, but maybe in the future ! Releasing many poms Imagine the sprint is almost finished now and it’s now time to release the projects. Type the gav li fr.lteconsulting again to get the GAVs list (fr.lteconsulting is my projects package name, so I filter GAVs with that), choose one and let’s release it : fr.lteconsulting:hexa.binding.samples:1.4-SNAPSHOT The thing in the release is to have all direct and transitive dependencies released too. That’s what Pom Explorer checks. It then generates a change list to materialize your requirements. Other use cases Listing provided and referenced classes You can ask which Java classes are provided and referenced by GAVs. That’s sometimes a useful information to have. Try those commands : classes providedBy fr.lteconsulting:hexa.css:1.3 classes referencedBy fr.lteconsulting:hexa.css:1.3 Optimizing your project’s dependencies Sometimes, you ask yourself “do I still need this and that dependency ?” but you are not very sure, and since you lack time to investigate, eventually the dependency stays in your project for a long time, causing of course maintenance issues sometime. Let’s have Pom Explorer help us in the quest for the obsolete dependency. garbage dep fr.lteconsulting:carousel:1.0-SNAPSHOT This will give you something like that : You can refer to the project documentation to find how to use those informations. But sure that it can help you give away those useless dependencies ! Other goodies : graphs ! Pom Explorer can do two other things to help you visualize your dependency graph : export GraphML files so you can use them in another graph software (like yEd for instance). display an interactive 3d graph Exporting GraphML files GraphML is an open format to describe graphs. With the graph exportcommand, you can get graphml files of your working session. The program will create two files and display the links to them. Those two files are corresponding to two graphs : the dependency graph as usual, and the dependency graph between the git repositories containing your projects. Sometime one git repository can contain multiple projects and a view of the dependencies at the repository level is useful in those cases. This is the kind of picture you can get easily from editors like yEd : Interactive 3D graph Thanks to the WebGL standard which allows direct access to the 3D hardware on the running machine and thanks to libraries like three.js and ngraph.pixel, it is possible to display an interacive 3d graph. More over it is possible to customize the appearance of the graph to give account of different perspectives. Type the graph command and click on the link. This will open another tab containing the living 3d graph of your projects. When focus is given to the 3d viewport, the W, A, S, F and arrow keys allow to move in the 3d space. On the right, there is a text area where you can edit some javascript callback to customize the graph appearance. You can also stop the moving of the particle with the checkbox at the bottom right of the screen. It is not necessarilly useful, but sometimes it is relaxing to admire your work in the form of a living and moving graph ! Conclusion There are many other functions in Pom Explorer, but they are for you to discover now. This tool finds easily its place in the daily workflow because of the functions it provides. The fact that one can run it locally or on a shared server allows to use it as you wish. It is still in early development phase so many more functionalities could come up. On this subject, don’t hesitate submitting a little pull request on the GitHub repository… Pom Explorer is made with love by LTE Consulting

It’s been a year since I started the quest for a highly-effective Data Knowledge Stack and the Hibernate Master Class contains over fifty articles already. Now that I covered many aspects of database transactions, JDBC and Java Persistence, it’s time to assemble all the pieces together into the High-Performance Java Persistence book. An Agile publishing experience Writing a book is a very time-consuming and stressful process and the last thing I needed was a very tight schedule. After reading Antonio Goncalves’s story, I chose the self-publishing way. In the end, I settled for Leanpub because it allows me to publish the book incrementally. This leads to a better engagement with readers, allowing me adapt the book content on the way. The content At its core, the book is about getting the most out of your persistence layer and that can only happen when your application resonates with the database system. Because concurrency is inherent to database processing, transactions play a very important role in this regard. The first part will be about some basic performance-related database concepts such as: locking, batching, connection pooling. In the second part, I will explain how an ORM can actually improve DML performance. This part will include the Hibernate Master Class findings. The third part is about advance querying techniques with jOOQ. If you enjoy reading this article, you might want to subscribe to my newsletter and get a discount for my book as well. Get involved The Agile methodologies are not just for software development. Writing a book in a Lean style can shorten the feed-back period and readers can get involved on the way. If you have any specific request or you are interested in this project, you can join my newsletter and follow my progress. Buy it! The book is 100% done, and you can check out the full Table of Content onLeanpub. If you enjoyed this article, I bet you are going to love my book as well. The ebook The PDF, ePUB and Kindle (MOBI) versions can be bought on Leanpub. The print version The print version is available on Amazon, Amazon.co.uk, Amazon.de or Amazon.fr. Presentations If you are not convinced, then check out the following two presentations: High-Performance JDBC from Voxxed Days Bucharest High-Performance Hibernate from JavaZone

[This article was written by Wyatt Lindsay] New Relic’s Community Forum is designed to be a place for our users to share their experiences, questions, problems, and fixes. The collective expertise and creativity of the New Relic community has generated some outstanding solutions to everyday issues, and we want to call out some of them in the area of .NET agent deployment excellence. Basic installation Installing New Relic’s .NET agent is designed to be simple: run the installer on the target host and choose the features you want to include. For Microsoft Azuredeployments, install one of our NuGet packages. Installation requires a reset of IIS for the software to load into your application. To upgrade, we recommend first stopping IIS, installing the newer agent version, and then starting up IIS again. It’s also possible to perform a “silent” (manual) install using msiexec.exe, for example: msiexec.exe /i C:\NewRelicAgent.msi /qb NR_LICENSE_KEY= INSTALLLEVEL=1 See the documentation for complete manual installation options. Leveraging PowerShell Scripting the silent installation provides convenience and flexibility. Here’s an example script provided by community member Jon Carl in this post: $msiName = $licenseKey = $arguments = "/i $msiName /L*v install.log /qn NR_LICENSE_KEY=$licenseKey" if ($msiName -ne $null) { $exitCode = (Start-Process -FilePath "msiexec" -ArgumentList $arguments -Wait -PassThru).ExitCode; if($exitCode -eq 0) { Write-Host "Installation successful!" -ForegroundColor Green } else { Write-Host "Installation unsuccessful. Exitcode: $exitCode" -ForegroundColor Red } } This script works great when run directly on the target machine. Another forum user (Kym McGain) noticed that the installation didn’t complete before the session ended when executing the script remotely. This caused the installer to quit partway through. Kym posted this script that uses a ‘while’ loop to ensure the installer completes. As a bonus, it stops IIS before and restarts it after the software installs. As mentioned above, these steps are usually needed when upgrading. $installNewRelic = { $runProcess = { param($process,$arguments) $res = Start-Process -FilePath $process -ArgumentList $arguments -Wait -PassThru while ($res.HasExited -eq $false) { Write-Host "Waiting for $process..." Start-Sleep -s 1 } $exitCode = $res.ExitCode if($exitCode -eq 0) { Write-Host "$process successful!" -ForegroundColor Green } else { Write-Host "$process unsuccessful. Exitcode: $exitCode" -ForegroundColor Red } } $msiName = $licenseKey = $arguments = "/i $msiName /L*v install.log /qn NR_LICENSE_KEY=$licenseKey" Invoke-Command $runProcess -ArgumentList "IISRESET","/STOP" Invoke-Command $runProcess -ArgumentList "msiexec.exe",$arguments Invoke-Command $runProcess -ArgumentList "IISRESET","/START" } Chef, Puppet, and Chocolatey Deployment options abound for modern Web developers. These solutions often require a known download path and installer name. New Relic offers a consistent filepath and MSI name for the agent in an effort to make automated deployment easier for .NET customers: http://download.newrelic.com/dot_net_agent/release/NewRelicDotNetAgent_x64.msi http://download.newrelic.com/dot_net_agent/release/NewRelicDotNetAgent_x86.msi Several Community members have created packages for these utilities. Chocolatey users are invited to use the following NuGet package created by kireevco: https://chocolatey.org/packages/newrelic-dotnet New Relic community member ePitty built a Puppet module to handle .NET agent deployment: https://github.com/epitty1023/puppet-newrelicappmon Chef users, meanwhile, can check out the following cookbook for .NET and many other platforms New Relic supports: http://community.opscode.com/cookbooks/newrelic New Relic Community member E_Bow wrote a Chef recipe that goes a step further by stopping IIS before the installation and starting it again after completion: #Stop IIS iis_site 'Website' do action [:stop] end # install latest Newrelic agent from web include_recipe 'newrelic::repository' include_recipe node['newrelic']['dotnet-agent']['dotnet_recipe'] license = node['newrelic']['application_monitoring']['license'] windows_package 'Install New Relic .NET Agent' do source node['newrelic']['dotnet-agent']['https_download'] options "/qb NR_LICENSE_KEY=#{license} INSTALLLEVEL=#{node['newrelic']['dotnet-agent']['install_level']}" installer_type :msi action :install end #Start IIS iis_site 'Website' do action [:start] end The author states that they were unable to pull the New Relic license key from the configuration JSON in Chef Overrides, requiring them to modify the config file on each machine and manually enter the key. We invite any Chef experts out there to extend and improve this recipe so that it correctly pulls the license key. We are continually impressed by the smarts and spirit of our New Relic Community Forum members, and jump at the chance to highlight their contributions. Look for more Forum projects in the New Relic blog in the future. Do you have your own approach, tips, or recipes? Please share them in the New Relic Community Forum.

Occasionally we are asked about JBoss BPM Suite integration with other products and layers in an enterprises architecture. We have published articles talking about how to achieve this with various aspects such as: Microservices integration Data integration Articles are one thing, but seeing is believing, so we have done a few webinars to show you live how to tackle integration: Data integration webinar PEX webinar Along with these articles we have always published demo projects that give you a closer look and chance to get hands on with these integration strategies: JBoss BPM Suite & JBoss Fuse Travel microservices story JBoss BPM Suite & JBoss Data Virtualization integration Imported Signavio Process Editor mortgage workflow. There is another integration story yet to be told about how one can leverage other tooling together with JBoss BPM Suite. This article will introduce one such company,Signavio, that provides a Signavio Process Editor so"...you can start modeling and engaging your organization in improving operational efficiency through the development of optimal models..." The following demo project provides a working example of how you can model an example mortgage process in Signavio Process Editor and then bring it into JBoss BPM Suite where you can add implementation details, integration details and other implementation details to finally execute the mortgage process end-to-end. Demo project As always we bring you not only a story, but a reusable demo project you can easily spin up yourself to explore the details around how a JBoss BPM project would integrate with the model designed in Signavio Process Editor. The project is called the JBoss BPM Suite & Signavio Process Editor Integration Demo. The project installs JBoss BPM Suite 6.1 with an example mortgage project with rules, process, forms and other artifacts. It also includes a copy of an exported Signavio Process Editor mortgage process that we then show how to import. Final mortgage workflow project with implementation details and integration details completed. Ready to run! This gives you the initial starting point after importing the Signavio process and the completely integrated final mortgage project that you can run side-by-side. To setup this project there are just a few simple steps to get going and will be up and running minutes: Installation Download and unzip. Add products to installs directory. Run 'init.sh' or 'init.bat' file. 'init.bat' must be run with Administrative privileges. Start JBoss BPMS Server by running 'standalone.sh' or 'standalone.bat' in the /target/jboss-eap-6.1/bin directory. Login to http://localhost:8080/business-central - login for admin, appraisor, broker, and manager roles (u:erics / p:bpmsuite1!) Mortgage Loan demo pre-installed as project. Using process designer, import the Signavio process that was exported to the file found in: support/MortgageDemoSignavio.bpmn Looking to Automate your business? See screenshots provided in project for how this should look and note that the JBoss BPM Suite process designer included validation that puts messages about tasks not specified, this is correct as at this point you need to start implementing the process tasks. You can examine the imported process and note the various details captured during initial workshops have been put into the process details for each step in the workflow. After implementing these steps you will find the final process ready to run. You can now explore the final project by deploying it and starting a new instance. We hope you enjoy this example project and feel free to browse for more at JBoss Demo Central.