This article explains how errors are handled when using the messaging system with Spring Integration and how to handle route and redirect to specific channel.

if someone asked you to develop a rest api on the jvm, which frameworks would you use? i was recently tasked with such a project. my client asked me to implement a rest api to ingest requests from a 3rd party. the project entailed consuming xml requests, storing the data in a database, then exposing the data to internal application with a json endpoint. finally, it would allow taking in a json request and turning it into an xml request back to the 3rd party. with the recent release of apache camel 2.14 and my success using it , i started by copying my apache camel / cxf / spring boot project and trimming it down to the bare essentials. i whipped together a simple hello world service using camel and spring mvc. i also integrated swagger into both. both implementations were pretty easy to create ( sample code ), but i decided to use spring mvc. my reasons were simple: its rest support was more mature, i knew it well, and spring mvc test makes it easy to test apis. camel's swagger support without web.xml as part of the aforementioned spike, i learned out how to configure camel's rest and swagger support using spring's javaconfig and no web.xml. i made this into a sample project and put it on github as camel-rest-swagger . this article shows how i built a rest api with java 8, spring boot/mvc, jaxb and spring data (jpa and rest components). i stumbled a few times while developing this project, but figured out how to get over all the hurdles. i hope this helps the team that's now maintaining this project (my last day was friday) and those that are trying to do something similar. xml to java with jaxb the data we needed to ingest from a 3rd party was based on the ncpdp standards. as a member, we were able to download a number of xsd files, put them in our project and generate java classes to handle the incoming/outgoing requests. i used the maven-jaxb2-plugin to generate the java classes. org.jvnet.jaxb2.maven2 maven-jaxb2-plugin 0.8.3 generate -xtostring -xequals -xhashcode -xcopyable org.jvnet.jaxb2_commons jaxb2-basics 0.6.4 src/main/resources/schemas/ncpdp the first error i ran into was about a property already being defined. [info] --- maven-jaxb2-plugin:0.8.3:generate (default) @ spring-app --- [error] error while parsing schema(s).location [ file:/users/mraible/dev/spring-app/src/main/resources/schemas/ncpdp/structures.xsd{1811,48}]. com.sun.istack.saxparseexception2; systemid: file:/users/mraible/dev/spring-app/src/main/resources/schemas/ncpdp/structures.xsd; linenumber: 1811; columnnumber: 48; property "multipletimingmodifierandtimingandduration" is already defined. use to resolve this conflict. at com.sun.tools.xjc.errorreceiver.error(errorreceiver.java:86) i was able to workaround this by upgrading to maven-jaxb2-plugin version 0.9.1. i created a controller and stubbed out a response with hard-coded data. i confirmed the incoming xml-to-java marshalling worked by testing with a sample request provided by our 3rd party customer. i started with a curl command, because it was easy to use and could be run by anyone with the file and curl installed. curl -x post -h 'accept: application/xml' -h 'content-type: application/xml' \ --data-binary @sample-request.xml http://localhost:8080/api/message -v this is when i ran into another stumbling block: the response wasn't getting marshalled back to xml correctly. after some research, i found out this was caused by the lack of @xmlrootelement annotations on my generated classes. i posted a question to stack overflow titled returning jaxb-generated elements from spring boot controller . after banging my head against the wall for a couple days, i figured out the solution . i created a bindings.xjb file in the same directory as my schemas. this causes jaxb to generate @xmlrootelement on classes. to add namespaces prefixes to the returned xml, i had to modify the maven-jaxb2-plugin to add a couple arguments. -extension -xnamespace-prefix and add a dependency: org.jvnet.jaxb2_commons jaxb2-namespace-prefix 1.1 then i modified bindings.xjb to include the package and prefix settings. i also moved into a global setting. i eventually had to add prefixes for all schemas and their packages. i learned how to add prefixes from the namespace-prefix plugins page . finally, i customized the code-generation process to generate joda-time's datetime instead of the default xmlgregoriancalendar . this involved a couple custom xmladapters and a couple additional lines in bindings.xjb . you can see the adapters and bindings.xjb with all necessary prefixes in this gist . nicolas fränkel's customize your jaxb bindings was a great resource for making all this work. i wrote a test to prove that the ingest api worked as desired. @runwith(springjunit4classrunner.class) @springapplicationconfiguration(classes = application.class) @webappconfiguration @dirtiescontext(classmode = dirtiescontext.classmode.after_class) public class initiaterequestcontrollertest { @inject private initiaterequestcontroller controller; private mockmvc mockmvc; @before public void setup() { mockitoannotations.initmocks(this); this.mockmvc = mockmvcbuilders.standalonesetup(controller).build(); } @test public void testgetnotallowedonmessagesapi() throws exception { mockmvc.perform(get("/api/initiate") .accept(mediatype.application_xml)) .andexpect(status().ismethodnotallowed()); } @test public void testpostpainitiationrequest() throws exception { string request = new scanner(new classpathresource("sample-request.xml").getfile()).usedelimiter("\\z").next(); mockmvc.perform(post("/api/initiate") .accept(mediatype.application_xml) .contenttype(mediatype.application_xml) .content(request)) .andexpect(status().isok()) .andexpect(content().contenttype(mediatype.application_xml)) .andexpect(xpath("/message/header/to").string("3rdparty")) .andexpect(xpath("/message/header/sendersoftware/sendersoftwaredeveloper").string("hid")) .andexpect(xpath("/message/body/status/code").string("010")); } } spring data for jpa and rest with jaxb out of the way, i turned to creating an internal api that could be used by another application. spring data was fresh in my mind after reading about it last summer. i created classes for entities i wanted to persist, using lombok's @data to reduce boilerplate. i read the accessing data with jpa guide, created a couple repositories and wrote some tests to prove they worked. i ran into an issue trying to persist joda's datetime and found jadira provided a solution. i added its usertype.core as a dependency to my pom.xml: org.jadira.usertype usertype.core 3.2.0.ga ... and annotated datetime variables accordingly. @column(name = "last_modified", nullable = false) @type(type="org.jadira.usertype.dateandtime.joda.persistentdatetime") private datetime lastmodified; with jpa working, i turned to exposing rest endpoints. i used accessing jpa data with rest as a guide and was looking at json in my browser in a matter of minutes. i was surprised to see a "profile" service listed next to mine, and posted a question to the spring boot team. oliver gierke provided an excellent answer . swagger spring mvc's integration for swagger has greatly improved since i last wrote about it . now you can enable it with a @enableswagger annotation. below is the swaggerconfig class i used to configure swagger and read properties from application.yml . @configuration @enableswagger public class swaggerconfig implements environmentaware { public static final string default_include_pattern = "/api/.*"; private relaxedpropertyresolver propertyresolver; @override public void setenvironment(environment environment) { this.propertyresolver = new relaxedpropertyresolver(environment, "swagger."); } /** * swagger spring mvc configuration */ @bean public swaggerspringmvcplugin swaggerspringmvcplugin(springswaggerconfig springswaggerconfig) { return new swaggerspringmvcplugin(springswaggerconfig) .apiinfo(apiinfo()) .genericmodelsubstitutes(responseentity.class) .includepatterns(default_include_pattern); } /** * api info as it appears on the swagger-ui page */ private apiinfo apiinfo() { return new apiinfo( propertyresolver.getproperty("title"), propertyresolver.getproperty("description"), propertyresolver.getproperty("termsofserviceurl"), propertyresolver.getproperty("contact"), propertyresolver.getproperty("license"), propertyresolver.getproperty("licenseurl")); } } after getting swagger to work, i discovered that endpoints published with @repositoryrestresource aren't picked up by swagger. there is an open issue for spring data support in the swagger-springmvc project. liquibase integration i configured this project to use h2 in development and postgresql in production. i used spring profiles to do this and copied xml/yaml (for maven and application*.yml files) from a previously created jhipster project. next, i needed to create a database. i decided to use liquibase to create tables, rather than hibernate's schema-export. i chose liquibase over flyway based of discussions in the jhipster project . to use liquibase with spring boot is dead simple: add the following dependency to pom.xml, then place changelog files in src/main/resources/db/changelog . org.liquibase liquibase-core i started by using hibernate's schema-export and changing hibernate.ddl-auto to "create-drop" in application-dev.yml . i also commented out the liquibase-core dependency. then i setup a postgresql database and started the app with "mvn spring-boot:run -pprod". i generated the liquibase changelog from an existing schema using the following command (after downloading and installing liquibase). liquibase --driver=org.postgresql.driver --classpath="/users/mraible/.m2/repository/org/postgresql/postgresql/9.3-1102-jdbc41/postgresql-9.3-1102-jdbc41.jar:/users/mraible/snakeyaml-1.11.jar" --changelogfile=/users/mraible/dev/spring-app/src/main/resources/db/changelog/db.changelog-02.yaml --url="jdbc:postgresql://localhost:5432/mydb" --username=user --password=pass generatechangelog i did find one bug - the generatechangelog command generates too many constraints in version 3.2.2 . i was able to fix this by manually editing the generated yaml file. tip: if you want to drop all tables in your database to verify liquibase creation is working in postgesql, run the following commands: psql -d mydb drop schema public cascade; create schema public; after writing minimal code for spring data and configuring liquibase to create tables/relationships, i relaxed a bit, documented how everything worked and added a loggingfilter . the loggingfilter was handy for viewing api requests and responses. @bean public filterregistrationbean loggingfilter() { loggingfilter filter = new loggingfilter(); filterregistrationbean registrationbean = new filterregistrationbean(); registrationbean.setfilter(filter); registrationbean.seturlpatterns(arrays.aslist("/api/*")); return registrationbean; } accessing api with resttemplate the final step i needed to do was figure out how to access my new and fancy api with resttemplate . at first, i thought it would be easy. then i realized that spring data produces a hal -compliant api, so its content is embedded inside an "_embedded" json key. after much trial and error, i discovered i needed to create a resttemplate with hal and joda-time awareness. @bean public resttemplate resttemplate() { objectmapper mapper = new objectmapper(); mapper.configure(deserializationfeature.fail_on_unknown_properties, false); mapper.registermodule(new jackson2halmodule()); mapper.registermodule(new jodamodule()); mappingjackson2httpmessageconverter converter = new mappingjackson2httpmessageconverter(); converter.setsupportedmediatypes(mediatype.parsemediatypes("application/hal+json")); converter.setobjectmapper(mapper); stringhttpmessageconverter stringconverter = new stringhttpmessageconverter(); stringconverter.setsupportedmediatypes(mediatype.parsemediatypes("application/xml")); list> converters = new arraylist<>(); converters.add(converter); converters.add(stringconverter); return new resttemplate(converters); } the jodamodule was provided by the following dependency: com.fasterxml.jackson.datatype jackson-datatype-joda with the configuration complete, i was able to write a messagesapiitest integration test that posts a request and retrieves it using the api. the api was secured using basic authentication, so it took me a bit to figure out how to make that work with resttemplate. willie wheeler's basic authentication with spring resttemplate was a big help. @runwith(springjunit4classrunner.class) @contextconfiguration(classes = integrationtestconfig.class) public class messagesapiitest { private final static log log = logfactory.getlog(messagesapiitest.class); @value("http://${app.host}/api/initiate") private string initiateapi; @value("http://${app.host}/api/messages") private string messagesapi; @value("${app.host}") private string host; @inject private resttemplate resttemplate; @before public void setup() throws exception { string request = new scanner(new classpathresource("sample-request.xml").getfile()).usedelimiter("\\z").next(); responseentity response = resttemplate.exchange(gettesturl(initiateapi), httpmethod.post, getbasicauthheaders(request), org.ncpdp.schema.transport.message.class, collections.emptymap()); assertequals(httpstatus.ok, response.getstatuscode()); } @test public void testgetmessages() { httpentity request = getbasicauthheaders(null); responseentity> result = resttemplate.exchange(gettesturl(messagesapi), httpmethod.get, request, new parameterizedtypereference>() {}); httpstatus status = result.getstatuscode(); collection messages = result.getbody().getcontent(); log.debug("messages found: " + messages.size()); assertequals(httpstatus.ok, status); for (message message : messages) { log.debug("message.id: " + message.getid()); log.debug("message.datecreated: " + message.getdatecreated()); } } private httpentity getbasicauthheaders(string body) { string plaincreds = "user:pass"; byte[] plaincredsbytes = plaincreds.getbytes(); byte[] base64credsbytes = base64.encodebase64(plaincredsbytes); string base64creds = new string(base64credsbytes); httpheaders headers = new httpheaders(); headers.add("authorization", "basic " + base64creds); headers.add("content-type", "application/xml"); if (body == null) { return new httpentity<>(headers); } else { return new httpentity<>(body, headers); } } } to get spring data to populate the message id, i created a custom restconfig class to expose it. i learned how to do this from tommy ziegler . /** * used to expose ids for resources. */ @configuration public class restconfig extends repositoryrestmvcconfiguration { @override protected void configurerepositoryrestconfiguration(repositoryrestconfiguration config) { config.exposeidsfor(message.class); config.setbaseuri("/api"); } } summary this article explains how i built a rest api using jaxb, spring boot, spring data and liquibase. it was relatively easy to build, but required some tricks to access it with spring's resttemplate. figuring out how to customize jaxb's code generation was also essential to make things work. i started developing the project with spring boot 1.1.7, but upgraded to 1.2.0.m2 after i found it supported log4j2 and configuring spring data rest's base uri in application.yml. when i handed the project off to my client last week, it was using 1.2.0.build-snapshot because of a bug when running in tomcat . this was an enjoyable project to work on. i especially liked how easy spring data makes it to expose jpa entities in an api. spring boot made things easy to configure once again and liquibase seems like a nice tool for database migrations. if someone asked me to develop a rest api on the jvm, which frameworks would i use? spring boot, spring data, jackson, joda-time, lombok and liquibase. these frameworks worked really well for me on this particular project.

In this article, we learn how to utilize AngularJS's array filter features in a variety of use cases. Read on to get started.

As part of a project to create a GPU based reaction diffusion simulation, I stated to look at using Metal in Swift this weekend. I've done similar work in the past targeting the Flash Player and using AGAL. Metal is a far higher level language than AGAL: it's based on C++ with a richer syntax and includes compute functions. Whereas in AGAL, to run cellular automata, I'd create a rectangle out of two triangles with a vertex shader and execute the reaction diffusion functions in a separate fragment shader, a compute shader is more direct: I can get and set textures and it can operate of individual pixels of that texture without the need for a vertex shader. The Swift code I discuss in this article is based heavily on two articles at Metal By Example: Introduction to Compute Programming in Metal and Fundamentals of Image Processing in Metal. Both of which include Objective-C source code, so hopefully my Swift implementation will help some. My application has four main steps: initialise Metal, create a Metal texture from a UIImage, apply a kernel function to that texture, convert the newly generated texture back into a UIImage and display it. I'm using a simple example shader that changes the saturation of the input image. so I've also added a slider that changes the saturation value. Let's look at each step one by one: Initialising Metal Initialising Metal is pretty simple: inside my view controller's overridden viewDidLoad(), I create a pointer to the default Metal device: var device: MTLDevice! = nil [...] device = MTLCreateSystemDefaultDevice() I also need to create a library and command queue: defaultLibrary = device.newDefaultLibrary() commandQueue = device.newCommandQueue() Finally, I add a reference to my Metal function to the library and synchronously create and compile a compute pipeline state: et kernelFunction = defaultLibrary.newFunctionWithName("kernelShader") pipelineState = device.newComputePipelineStateWithFunction(kernelFunction!, error: nil) The kernelShader points to the saturation image processing function, written in Metal, that lives in my Shaders.metal file: kernel void kernelShader(texture2d inTexture [[texture(0)]], texture2d outTexture [[texture(1)]], constant AdjustSaturationUniforms &uniforms [[buffer(0)]], uint2 gid [[thread_position_in_grid]]) { float4 inColor = inTexture.read(gid); float value = dot(inColor.rgb, float3(0.299, 0.587, 0.114)); float4 grayColor(value, value, value, 1.0); float4 outColor = mix(grayColor, inColor, uniforms.saturationFactor); outTexture.write(outColor, gid); } Creating a Metal Texture from a UIIMage There are a few steps in converting a UIImage into a MTLTexture instance. I create an array of UInt8 to hold an emptyCGBitmapInfo, then use CGContextDrawImage() to copy the image into a bitmap context let image = UIImage(named: "grand_canyon.jpg") let imageRef = image.CGImage let imageWidth = CGImageGetWidth(imageRef) let imageHeight = CGImageGetHeight(imageRef) let bytesPerRow = bytesPerPixel * imageWidth var rawData = [UInt8](count: Int(imageWidth * imageHeight * 4), repeatedValue: 0) let bitmapInfo = CGBitmapInfo(CGBitmapInfo.ByteOrder32Big.toRaw() | CGImageAlphaInfo.PremultipliedLast.toRaw()) let context = CGBitmapContextCreate(&rawData, imageWidth, imageHeight, bitsPerComponent, bytesPerRow, rgbColorSpace, bitmapInfo) CGContextDrawImage(context, CGRectMake(0, 0, CGFloat(imageWidth), CGFloat(imageHeight)), imageRef) Once all of those steps have executed, I can create a new texture use its replaceRegion() method to write the image into it: let textureDescriptor = MTLTextureDescriptor.texture2DDescriptorWithPixelFormat(MTLPixelFormat.RGBA8Unorm, width: Int(imageWidth), height: Int(imageHeight), mipmapped: true) texture = device.newTextureWithDescriptor(textureDescriptor) let region = MTLRegionMake2D(0, 0, Int(imageWidth), Int(imageHeight)) texture.replaceRegion(region, mipmapLevel: 0, withBytes: &rawData, bytesPerRow: Int(bytesPerRow)) I also create an empty texture which the kernel function will write into: let outTextureDescriptor = MTLTextureDescriptor.texture2DDescriptorWithPixelFormat(texture.pixelFormat, width: texture.width, height: texture.height, mipmapped: false) outTexture = device.newTextureWithDescriptor(outTextureDescriptor) Invoking the Kernel Function The next block of work is to set the textures and another variable on the kerne function and execute the shader. The first step is to instantiate a command buffer and command encoder: let commandBuffer = commandQueue.commandBuffer() let commandEncoder = commandBuffer.computeCommandEncoder() ...then set the pipeline state (we got from device.newComputePipelineStateWithFunction() earlier) and textures on the command encoder: commandEncoder.setComputePipelineState(pipelineState) commandEncoder.setTexture(texture, atIndex: 0) commandEncoder.setTexture(outTexture, atIndex: 1) The filter requires an addition parameter that defines the saturation amount. This is passed into the shader via anMTLBuffer. To populate the buffer, I've created a small struct: struct AdjustSaturationUniforms { var saturationFactor: Float } Then newBufferWithBytes() to pass in my saturationFactor float value: var saturationFactor = AdjustSaturationUniforms(saturationFactor: self.saturationFactor) var buffer: MTLBuffer = device.newBufferWithBytes(&saturationFactor, length: sizeof(AdjustSaturationUniforms), options: nil) commandEncoder.setBuffer(buffer, offset: 0, atIndex: 0) This is now accessible inside the shader as an argument to its kernel function: constant AdjustSaturationUniforms &uniforms [[buffer(0)]] Now I'm ready invoke the function itself. Metal kernel functions use thread groups to break up their workload into chunks. In my example, I create 64 thread groups, then send them off to the GPU: let threadGroupCount = MTLSizeMake(8, 8, 1) let threadGroups = MTLSizeMake(texture.width / threadGroupCount.width, texture.height / threadGroupCount.height, 1) commandQueue = device.newCommandQueue() commandEncoder.dispatchThreadgroups(threadGroups, threadsPerThreadgroup: threadGroupCount) commandEncoder.endEncoding() commandBuffer.commit() commandBuffer.waitUntilCompleted() Converting the Texture to a UIImage Finally, now that the kernel function has executed, we need to do the reverse of above and get the image held inoutTexture into a UIImage so it can be displayed. Again, I use a region to define the size and the texture's getBytes() to populate an array on UInt8: let imageSize = CGSize(width: texture.width, height: texture.height) let imageByteCount = Int(imageSize.width * imageSize.height * 4) let bytesPerRow = bytesPerPixel * UInt(imageSize.width) var imageBytes = [UInt8](count: imageByteCount, repeatedValue: 0) let region = MTLRegionMake2D(0, 0, Int(imageSize.width), Int(imageSize.height)) outTexture.getBytes(&imageBytes, bytesPerRow: Int(bytesPerRow), fromRegion: region, mipmapLevel: 0) Now that imageBytes holds the raw data, it's a few lines to create a CGImage: let providerRef = CGDataProviderCreateWithCFData( NSData(bytes: &imageBytes, length: imageBytes.count * sizeof(UInt8)) ) let bitmapInfo = CGBitmapInfo(CGBitmapInfo.ByteOrder32Big.toRaw() | CGImageAlphaInfo.PremultipliedLast.toRaw()) let renderingIntent = kCGRenderingIntentDefault let imageRef = CGImageCreate(UInt(imageSize.width), UInt(imageSize.height), bitsPerComponent, bitsPerPixel, bytesPerRow, rgbColorSpace, bitmapInfo, providerRef, nil, false, renderingIntent) imageView.image = UIImage(CGImage: imageRef) ...and we're done! Metal requires an A7 or A8 processor and this code has been built and tested under Xcode 6. All the source code is available at my GitHub repository here.

The other day, Morgan at Swift London mentioned it may be interesting to use my Swift node based user interface as the basis for an audio synthesiser. Always ready for a challenge, I've spent a little time looking into Core Audio to see how this could be done and created a little demonstration app: a multi channel tone generator. I've done something not too dissimilar targeting Flash in the past. In that project, I had to manually create 8192 samples to synthesise a tone and ended up using ActionScript Workers to do that work in the background. After some poking around, it seems a similar approach can be taken in Core Audio, but to create pure sine waves there's a far simpler way: using Audio Toolbox. Luckily, I found this excellent article by Gene De Lisa. His SwiftSimpleGraph project has all the boilerplate code to create sine waves, so all I had to do was add a user interface. My project contains four ToneWidget instances, each of which contain numeric dials for frequency and velocity and asine wave renderer. There's also an additional sine wave renderer that displays the composite frequency of all four channels. The sine wave renderer creates a bitmap image of the wave based on some code Joseph Lord tweaked in my Swift reaction diffusion code in the summer. It exposes a setFrequencyVelocityPairs() method which accepts an array ofFrequencyVelocityPair instances. When that's invoked, the drawSineWave() method loops over the array creating and summing vertical values for each column in the bitmap: for i in 1 ..< Int(frame.width) { let scale = M_PI * 5 let curveX = Double(i) var curveY = Double(frame.height / 2) for pair in frequencyVelocityPairs { let frequency = Double(pair.frequency) / 127.0 let velocity = Double(pair.velocity) / 127.0 curveY += ((sin(curveX / scale * frequency * 5)) * (velocity * 10)) } [...] Then, rather than simply plotting the generated position for each column, it draws a line between the newly calculated vertical position for the current column and the previous vertical position for the previous column: for yy in Int(min(previousCurveY, curveY)) ... Int(max(previousCurveY, curveY)) { let pixelIndex : Int = (yy * Int(frame.width) + i); pixelArray[pixelIndex].r = UInt8(255 * colorRef[0]); pixelArray[pixelIndex].g = UInt8(255 * colorRef[1]); pixelArray[pixelIndex].b = UInt8(255 * colorRef[2]); } The result is a continuous wave: Because the sine wave renderer accepts an array of values, I'm able to use the same component for both the individual channels (where the array length is one) and for the composite of all four (where the array length is four). I was ready to use GCD to do the sine wave drawing in a background thread, but both the simulator and my old iPad happily do this in the main thread keeping the user interface totally responsive. Up in the view controller, I have an array containing each widget and another array containing the currently playing notes which is populated inside viewDidLoad(): override func viewDidLoad() { super.viewDidLoad() view.addSubview(sineWaveRenderer) for i in 0 ... 3 { let toneWidget = ToneWidget(index: i, frame: CGRectZero) toneWidget.addTarget(self, action: "toneWidgetChangeHandler:", forControlEvents: UIControlEvents.ValueChanged) toneWidgets.append(toneWidget) view.addSubview(toneWidget) currentNotes.append(toneWidget.getFrequencyVelocityPair()) soundGenerator.playNoteOn(UInt32(toneWidget.getFrequencyVelocityPair().frequency), velocity: UInt32(toneWidget.getFrequencyVelocityPair().velocity), channelNumber: UInt32(toneWidget.getIndex())) } } When the frequency or the velocity is changed by the user in any of those widgets, I use the value in thecurrentNotes array to switch off the currently playing note, update the master sine wave renderer and play the new note: func toneWidgetChangeHandler(toneWidget : ToneWidget) { soundGenerator.playNoteOff(UInt32(currentNotes[toneWidget.getIndex()].frequency), channelNumber: UInt32(toneWidget.getIndex())) updateSineWave() soundGenerator.playNoteOn(UInt32(toneWidget.getFrequencyVelocityPair().frequency), velocity: UInt32(toneWidget.getFrequencyVelocityPair().velocity), channelNumber: UInt32(toneWidget.getIndex())) currentNotes[toneWidget.getIndex()] = toneWidget.getFrequencyVelocityPair() } The updateSineWave() method simply loops over the widgets, gets each value and passes those into the sine wave renderer: func updateSineWave() { var values = [FrequencyVelocityPair]() for widget in toneWidgets { values.append(widget.getFrequencyVelocityPair()) } sineWaveRenderer.setFrequencyVelocityPairs(values) } Once again, big thanks to Gene De Lisa who has really done all the hard work navigating the Core Audio and Audio Toolbox API research on this. All of the source code for this project is available at my GitHub repository here.

I have been playing around with converting an application that I have to use Spring @Configuration mechanism to configure connectivity to RabbitMQ - originally I had the configuration described using an xml bean definition file. So this was my original configuration: This is a fairly simple configuration that : sets up a connection to a RabbitMQ server, creates a durable queue(if not available) creates a durable exchange and configures a binding to send messages to the exchange to be routed to the queue based on a routing key called "rube.key" This can be translated to the following @Configuration based java configuration: @Configuration public class RabbitConfig { @Autowired private ConnectionFactory rabbitConnectionFactory; @Bean DirectExchange rubeExchange() { return new DirectExchange("rmq.rube.exchange", true, false); } @Bean public Queue rubeQueue() { return new Queue("rmq.rube.queue", true); } @Bean Binding rubeExchangeBinding(DirectExchange rubeExchange, Queue rubeQueue) { return BindingBuilder.bind(rubeQueue).to(rubeExchange).with("rube.key"); } @Bean public RabbitTemplate rubeExchangeTemplate() { RabbitTemplate r = new RabbitTemplate(rabbitConnectionFactory); r.setExchange("rmq.rube.exchange"); r.setRoutingKey("rube.key"); r.setConnectionFactory(rabbitConnectionFactory); return r; } } This configuration should look much more simpler than the xml version of the configuration. I am cheating a little here though, you should be seeing a missing connectionFactory which is just being injected into this configuration, where is that coming from..this is actually part of a Spring Boot based application and there is a Spring Boot Auto configuration for RabbitMQ connectionFactory based on whether the RabbitMQ related libraries are present in the classpath. Here is the complete configuration if you are interested in exploring further - https://github.com/bijukunjummen/rg-si-rabbit/blob/master/src/main/java/rube/config/RabbitConfig.java References: Spring-AMQP project here Spring-Boot starter project using RabbitMQ here

Sublime Text Editor can help you write in AngularJS much more quickly.

One of the ways Spring recommends injecting inter-dependencies between beans is shown in the following sample copied from the Spring's reference guide here: @Configuration public class AppConfig { @Bean public Foo foo() { return new Foo(bar()); } @Bean public Bar bar() { return new Bar("bar1"); } } So here, bean `foo` is being injected with a `bar` dependency. However, there is one alternate way to inject dependency that is not documented well, it is to just take the dependency as a `@Bean` method parameter this way: @Configuration public class AppConfig { @Bean public Foo foo(Bar bar) { return new Foo(bar); } @Bean public Bar bar() { return new Bar("bar1"); } } There is a catch here though, the injection is now by type, the `bar` dependency would be resolved by type first and if duplicates are found, then by name: @Configuration public static class AppConfig { @Bean public Foo foo(Bar bar1) { return new Foo(bar1); } @Bean public Bar bar1() { return new Bar("bar1"); } @Bean public Bar bar2() { return new Bar("bar2"); } } In the above sample dependency `bar1` will be correctly injected. If you want to be more explicit about it, an @Qualifer annotation can be added in: @Configuration public class AppConfig { @Bean public Foo foo(@Qualifier("bar1") Bar bar1) { return new Foo(bar1); } @Bean public Bar bar1() { return new Bar("bar1"); } @Bean public Bar bar2() { return new Bar("bar2"); } } So now the question of whether this is recommended at all, I would say yes for certain cases. For eg, had the bar bean been defined in a different @Configuration class , the way to inject the dependency then is along these lines: @Configuration public class AppConfig { @Autowired @Qualifier("bar1") private Bar bar1; @Bean public Foo foo() { return new Foo(bar1); } } I find the method parameter approach simpler here: @Configuration public class AppConfig { @Bean public Foo foo(@Qualifier("bar1") Bar bar1) { return new Foo(bar1); } }

in this jquery mobile tutorial we will create the screens that will handle user registration, login and logout in a real-world meeting room booking application. this article is part of a series of mobile application development tutorials that i have been publishing on my blog jorgeramon.me. if you are new to this series, i recommend that you read its first part, as well as this mobile ui patterns article where i provide a flowchart describing the user registration, login and logout screens in a mobile application. we will use this chart as a guide for this article. here’s a screenshot: in this part of the tutorial we will only create the static html for the screens. in future articles we will implement the programming logic that makes the pages work. the first step we are going to take is to set up a jquery mobile project for the app. how to set up a jquery mobile project while you can use mobile sdks such as kendo ui mobile and intel xdk to create, debug and deploy jquery mobile apps, in this tutorial i will show you how to create a simple jquery mobile project without using the facilities provided by those sdks. i think that it’s important to understand how you can create this type of project from scratch, and how the different pieces in the project work together in an app. the project’s directories and files we need to pick a directory in our development workstations where we will place the project’s files. in my case i named that directory “apps”. in that directory, we will create a root directory for the application, which we will name “conf-rooms”. make sure that this directory is set up so it can be accessed from your local web server. under “conf-rooms” we will create a “css” directory, where we will place the css assets of the project; and an “img” directory for the images that we will use. at the same level of the “apps” directory, we will create a “lib” directory. this is where we will place the jquery mobile and any other libraries that our application will use. you also need to set up this directory so it can be accessed from your local web server. on my workstation the directories look as depicted below: now is a good time to download the jquery mobile and jquery libraries from their respective websites, and place them in the “jqm” and “jquery” directories, all under the “lib” directory. this is how the files look on my workstation: how jquery mobile works a short overview of jquery mobile for those who aren’t very familiar with it yet. as its documentation clearly explains, jquery mobile is a unified user interface system with the following characteristics: it works seamlessly across all popular mobile device platforms. it uses jquery and jquery ui as its foundations. it has a lightweight codebase built on progressive enhancement. it has a flexible and easily themeable design. an attribute that differentiates jquery mobile from other frameworks is that it targets a wide variety of mobile browsers. the reason this coverage is possible has to do with the way jquery mobile works. jquery mobile works by applying css and javascript enhancements to html pages built with clean, semantic html. the usage of semantic html ensures compatibility with most web-enabled devices. the techniques applied by the framework to an html page, transform the semantic page into a rich and interactive experience. we call these changes progressive enhancements, as they are applied progressively to the page, taking advantage of the capabilities of the browser on the web-enabled device. the enhancements result in pages that provide a great user experience on the latest mobile browsers and degrade gracefully on less capable browsers, without losing their intrinsic functionality. in addition, the framework provides support for screen readers and other assistive technologies through a tight integration with the web accessibility initiative – accessible rich internet applications suite (wai-aria) technical specification. creating the landing screen the first application that we will create is the landing screen. this screen will come up when users launch our application. as reflected in the flowchart at the beginning of this article, the landing screen is the door to all the areas of the app, and it requires that users log in before navigating any further. in the “wireframes for signing in and signing up” section of the third part of this tutorial we created the following mockup for this screen. let’s create an empty index.html file in the “conf-rooms” directory, and add a jquery mobile page template to the file as follows: book it welcome! existing users sign in don't have an account? sign up before we step through this code i want you to check out this file in a mobile browser or simulator. the result should look like this screenshot: what do you think? back in the index.html file, in the head section we have references to the jquery and jquery mobile libraries. double check that yours are pointing to the correct directories in your workstation. how to use a custom theme in jquery mobile now i want to direct your attention to the following lines: these lines mean that we are using a custom jquery mobile theme that resides in the “conf-room1.min.css” file. i created this file using jquery mobile’s theme roller . we will use this theme to give our app a look different than the standard jquery mobile themes. you can download the theme using this link . after downloading the zipped theme files, we will go to the “css” directory, create a “css/themes/1″ directory and place the unzipped theme files there. when done, the “css” directory should look like this: in the head section of the index.html file we also have this code: app.css is the css file where we will place any additional custom styles that we will use in the app. for the moment, we will add the following code to the “app.css” file: /* change html headers color */ h1,h2,h3,h4,h5 { color:#0071bc; } h2.mc-text-danger, h3.mc-text-danger { color:red; } /* change border radius of icon buttons */ .ui-btn-icon-notext.ui-corner-all { -webkit-border-radius: .3125em; border-radius: .3125em; } /* change color of jquery mobile page headers */ .ui-title { color:#fff; } /* center-aligned text */ .mc-text-center { text-align:center; } /* top margin for some elements */ .mc-top-margin-1-5 { margin-top:1.5em; } these are just a few cosmetic changes that will enhance the look of the app. notice that i prefixed non-jquerymobile classes with the characters “mc-” to avoid potential collisions with jquerymobile’s classes. the remaining lines in the head section of index.html are the references to the jquery and jquery mobile libraries. as i suggested earlier, make sure that yours are pointing to the correct directories in your project. let’s move on to the body section of the “index.html file”. there you will find the standard jquery mobile page template with a header and main divs: book it welcome! existing users sign in don't have an account? sign up we have decorated the “header” div with the data-theme=”c” attribute, which gives it the nice purple background color that we defined in the custom theme: in the “main” div we are using a couple of links to the sign in and sign up screens respectively. the links point to the sign-in.html and sing-up.html files that we will create in a few minutes. these links are decorated with the jquery mobile ui-btn, ui-btn-b and ui-corner-all classes, which make them look like buttons: this is all we need to do in the lading page for the moment. let’s move on to the log in screen. creating a log in screen with jquery mobile here’s the log in screen’s mockup that we built in the third part of this tutorial : we will use the log in screen to capture the user’s credentials and validate them against the application’s user accounts database. if validation succeeds, we will direct users to a “main menu” scree that we will create in an upcoming tutorial. let’s create an empty sign-in.html file in the project’s directory. in the file, we will write the following code: book it sign in email address password remember me submit can't access your account? login failed did you enter the right credentials? ok if you open this sign-in.html with a mobile browser or emulator, you will see something like this: the head section of the html document is similar to the index.html file we created a few minutes ago, with the exception of the document’s title. no need to explain much there. in the “main” section of the jquery mobile page that wee added to the file, we dropped a few controls that will allow us to capture the user’s email and password, along with a checkbox that will let us know when the user wants the app to remember their credentials: sign in email address password remember me submit can't access your account? we also added a link that will allow users to initiate the password reset process if they have problems logging in. you will also notice that the “submit” link points to the “dlg-invalid-credentials” anchor defined in the same jquery mobile page. this link is decorated with the data-rel=”popup”, data-transition=”pop” and data-position-to=”window” attributes. when we do this, we are telling jquery mobile to open the link to the element with id=”dlg-invalid-credentials” as a popup dialog, using a “pop” transition, and center the element relative to the document’s window. here’s the html for the popup: login failed did you enter the right credentials? ok notice that the “dlg-invalid-credentials” div is decorated with the data-rel=”popup” attribute, signaling to jquery mobile to apply popup styles to this div. if you click or tap the “submit” button, you will see the “invalid credentials” popup: one last thing on this screen. we have the popup linked directly to the “submit” button for testing purposes. in an upcoming part of this tutorial we will add programming logic that will activate the popup only when the login fails. for the moment we are only concerned with creating the html code for the pages and making sure that the jquery mobile enhancements work on them. creating an account locked screen with jquery mobile many business applications use an account locked feature as a measure to increase the app’s security. we will use this feature in our app, and this means that we need to create an account locked screen. the purpose of the screen is to notify the user that their account is locked. we will define under which conditions an account will be locked through programming logic that we will add in an upcoming chapter of this tutorial. let’s create an empty account-locked.html file, and drop the following code in it: back app name your account is locked please contact the helpdesk to resolve this issue. the file should look like the screenshot below when viewed with a mobile browser or emulator: the html code for this screen is very similar to that in the prior two screens, with the exception of one element that i want you to pay attention to: back app name the header section of the jquery mobile page we just created contains a link to the sign-in.html file. when we decorate it with the ui-btn-left, ui-btn, ui-btn-icon-notext, ui-corner-all and ui-icon-back classes, we are giving the link the appearance of a toolbar button, just like this: the data-rel=”back” attribute causes any taps on the anchor to mimic a “back button”, going back one history entry and ignoring the anchor’s default href. you can read more about navigation and linking on jquery mobile by visiting jquery mobile’s navigation documentation. you should also visit the jquery mobile buttons guide to learn about how to create buttons. creating a sign up page with jquery mobile when users tap on the landing screen’s “sign up” button, they will open the sign up screen. this is where we will capture the user’s personal information so we can create an account for them. remember that our mockup of the sign up screen looks like this: let’s create an empty sign-up.html file and add the following code to it: book it sign up first name last name email address password confirm password submit almost done... confirm your email address we sent you an email with instructions on how to confirm your email address. please check your inbox and follow the instructions in the email. ok the file should look as depicted below when you open it with a mobile browser or emulator: the only difference with the mockup is that we are using a “submit” button at the bottom of the screen, instead of a “done” button in the toolbar. when you examine the html code, you will find that the “submit” button is wired to the “dlg-sign-up-sent” popup: almost done... confirm your email address we sent you an email with instructions on how to confirm your email address. please check your inbox and follow the instructions in the email. ok if you tap on the button, the popup will become visible: we will use this popup to notify the users that we have sent them a message asking them to confirm their email address. the message will contain a link to a webpage where users will need to re-enter the email address used to create their account in the app. with this step we are trying to make sure that it was is a human with a valid email inbox who created the account. back in the popup’s html code, notice how the “ok” button links back to the sign in screen. you should be able to confirm that this link works when you tap the button. creating a password reset screen with jquery mobile the app’s landing screen has a “can’t access your account?” link that helps user initiate the password reset workflow of the app. the first step of this workflow is to present the “begin password reset” screen to the user. we will use this screen to capture the user’s email address. if we find this email address in the user accounts database of the app, we will email the user a provisional password. next, we will activate the “end password reset” screen, where the user will need to enter the provisional password and a new password of their choosing. the picture below illustrates this process. let’s create an empty begin-password-reset.html file in the project’s directory. we will write the following code int the file: book it password reset enter your email address submit password reset check your inbox we sent you an email with instructions on how to reset your password. please check your inbox and follow the instructions in the email. ok this is how the screen should look when viewed on a mobile browser or emulator: there is nothing new in the html code of this screen. we wired the “submit” button so when a user taps it, the embedded “dlg-pwd-reset-sent” popup will become active: we did this for testing purposes. remember that we will add the programming logic that activates these popups in upcoming chapters of this tutorial. when a user taps the popup’s “ok” button, the application will navigate to the “end password reset” screen, which we will create next. the end password reset screen this is the screen where the user will enter the provisional password we sent them via email, along with a new password of their choosing. to create this screen we will add an empty “end-password-reset.html” file to the project. here’s the code that goes in the file: book it reset password provisional password new password confirm new password submit done your password was changed. ok the screen should look like the picture below when viewed with a mobile browser or emulator: we wired the “submit” button so it activates the embedded “dlg-pwd-changed” popup: this popup simply tells the user that their password was changed. tapping the “ok” button will make the app navigate back to the sign in screen, where the user can sign in with the new password. summary and next steps this concludes our first phase of work on the user registration, login and logout screens of the jquery mobile version of the app. i will emphasize again that in this phase we are not adding programming logic to the screens. we are simply creating a jquery mobile page for each screen and making sure that the visual elements within the screens adhere to the mockups that we created in previous chapters of this tutorial, as well as to the ui patterns flowchart that i mentioned at the beginning of this article. while we’ve made significant progress with the app at this point, it’s fair to say that we are just getting started. we are still missing the programming for this article’s screens, as well as the jquery mobile pages and programming for the screens that will allow users to browse and reserve meeting rooms, which is why we created the app in the first place. in the next chapter of this tutorial we will get started with the programming of the user profile screens we just created. don’t forget to sign up for my mailing list so you can be among the first to know when i publish the next update. stay tuned don’t miss any articles. get new articles and updates 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in this article i explained how spring built-in transformers works for while transforming object message to map message. sometimes the messages need to be transformed before they can be consumed to achieve a business purpose. for example, a producer uses a plain xml as its payload to produce a message, while a consumer is interested in java object or types like plain text ,name-value pairs, or json model. spring integration provides endpoints such as service activators, channel adapters, message bridges, gateways, transformers, filters, and routers. in this example how transformers endpoint transform object message to map message. references: spring integration spring with jms spring with junit mockrunner sts high level view spring-mockrunner.xml in spring-mockrunner.xml file, i defined mockqueue, mockqueueconnectionfactory for inbound queue, and outbound queue for quick testing purpose. inboundqueue is where you will publish object message from objecttomaptransformertest.java class. outboundqueue where this queue expecting mapmessage type object and this queue is listing mapmessagelistener.java class. for more information mockrunner works please check my previous article mockrunner with spring jms . pom.xml 4.0.0 org.springframework.samples spring-int-jms-basic 0.0.1-snapshot 1.6 utf-8 utf-8 3.2.3.release 1.0.13 1.7.5 4.11 org.springframework spring-context ${spring-framework.version} org.springframework spring-tx ${spring-framework.version} org.springframework.integration spring-integration-core 2.2.4.release org.springframework.integration spring-integration-jmx 2.2.4.release org.springframework.integration spring-integration-jms 2.2.4.release org.slf4j slf4j-api ${slf4j.version} compile ch.qos.logback logback-classic ${logback.version} runtime org.springframework spring-test ${spring-framework.version} test junit junit ${junit.version} test com.mockrunner mockrunner-jms 1.0.3 javax.jms jms 1.1 org.codehaus.jackson jackson-mapper-asl 1.9.3 compile spring-int-jms.xml the endpoint is configured to connect to a jms server, fetch the messages,and publish them onto a local channel i.e inputchannel. where as connection-factory, and destination referred mockqueueconnectionfactory, and mockqueue(inboundqueue) beans from spring-mockrunner.xml file. inputchannel and outputchannel defined as queue channel objecttomaptransformer: object-to-map-transformer element that takes the payload from the input channel original here mockrunner-in-queue object message and emits a name-value paired map object onto the output channel i.e outputchannel and outboundjmsadapter bean fetch this message and publish to queue i.e mockrunner-out-queue. inboundjmsadapter : inbound-channel-adapter bean is responsible for receiving messages from a jms server here it is reading from mock queue name mockrunner-in-queue see objecttomaptransformertest.java class. outboundjmsadapter : outbound-channel-adapter bean is responsible to fetch messages from the channel i.e outputchannel and publish them to jms queue or topic. in this outbounjmsadapter reading message outputchannel as mapmessage and publish to outboundqueue(mockrunner-out-queue). mapmessagelistener.java package com.spijb.listener; import javax.jms.jmsexception; import javax.jms.mapmessage; import javax.jms.session; import org.slf4j.logger; import org.slf4j.loggerfactory; import org.springframework.jms.listener.sessionawaremessagelistener; public class mapmessagelistener implements sessionawaremessagelistener { private static final logger log = loggerfactory.getlogger(mapmessagelistener.class); @override public void onmessage(mapmessage message, session session) throws jmsexception { log.info("message received \r\n"+message); } } it is plain mapmessagelistener class to print received message from queue. department.java package com.spijb.domain; import java.io.serializable; public class department implements serializable{ private static final long serialversionuid = 1l; private final integer deptno; private final string name; private final string location; public department() { deptno=10; name="sales"; location="tx"; } public department(integer dno,string name,string loc) { this.deptno=dno; this.name=name; this.location=loc; } public integer getdeptno() { return deptno; } public string getname() { return name; } public string getlocation() { return location; } @override public string tostring() { return this.deptno+"-> "+this.name+"->"+this.location; } } domain object to send as a message, by default constructor assign deptno 10 , name as sales, location as tx also provide parameter constructor. spring junit class objecttomaptransformertest.java package com.spijb.invoker; import javax.jms.jmsexception; import javax.jms.message; import javax.jms.objectmessage; import javax.jms.session; import org.junit.test; import org.junit.runner.runwith; import org.springframework.beans.factory.annotation.autowired; import org.springframework.jms.core.jmstemplate; import org.springframework.jms.core.messagecreator; import org.springframework.test.context.contextconfiguration; import org.springframework.test.context.junit4.springjunit4classrunner; import com.mockrunner.mock.jms.mockqueue; import com.spijb.domain.department; @runwith(springjunit4classrunner.class) @contextconfiguration({"classpath:spring-mockrunner.xml","classpath:spring-int-jms.xml"}) public class objecttomaptransformertest { @autowired private jmstemplate jmstemplate; @autowired private mockqueue inboundqueue; @test public void shouldsendmessage() throws interruptedexception { final department defaultdepartment = new department(); jmstemplate.send(inboundqueue,new messagecreator() { @override public message createmessage(session session) throws jmsexception { objectmessage objectmessage = session.createobjectmessage(); objectmessage.setobject(defaultdepartment); return objectmessage; } }); thread.sleep(5000); } } spring with junit class where you can send message to inputchannel i.e inboundqueue using mockrunner. output : info: started inboundjmsadapter oct 06, 2014 1:24:25 pm org.springframework.integration.endpoint.abstractendpoint start info: started org.springframework.integration.config.consumerendpointfactorybean#1 13:24:26.882 [org.springframework.jms.listener.defaultmessagelistenercontainer#0-1] info c.spijb.listener.mapmessagelistener - message received com.mockrunner.mock.jms.mockmapmessage: {location=tx, name=sales, deptno=10} oct 06, 2014 1:24:30 pm org.springframework.context.support.abstractapplicationcontext doclose info: closing org.springframework.context.support.genericapplicationcontext@5840979b: startup date [mon oct 06 13:24:25 cdt 2014]; root of context hierarchy oct 06, 2014 1:24:30 pm org.springframework.context.support.defaultlifecycleprocessor$lifecyclegroup stop info: stopping beans in phase 2147483647 in the above highlighted one is output as map.

This article shows how to mock your JMS infrastructure using MockRunner and test it using Spring.

eclipse has a great user interface (ui). but what if i want to do things from the command line, without the gui? for example to build one or more projects in the workspace without using the eclipse ui? with this, i can do automated check-outs and do automated builds. performed a command line project build with eclipse the solution to this: there is a command line version of eclipse which i can use to run eclipse in the command line version. inside the eclipse folder on windows, there is the eclipsec program which is the command-line version of eclipse: eclipsec program, a command line version of eclipse the options of this command line version (for eclipse kepler) are described here: http://help.eclipse.org/kepler/index.jsp?topic=%2forg.eclipse.platform.doc.isv%2freference%2fmisc%2fruntime-options.html for example eclipsec.exe -nosplash -application org.eclipse.cdt.managedbuilder.core.headlessbuild -data c:\my_wsp -build k64f will launch eclipse without splash screen ( -nosplash ), uses the - application command to load the managed make builder (which is used to build projects), with -data i specify the workspace to be used, and with the -build command it will the project k64f. more options and details are shown here: http://stackoverflow.com/questions/344797/build-several-cdt-c-projects-from-commandline and a very good article with additional background information how to use it with the gnu arm eclipse plubins can be found here: http://gnuarmeclipse.livius.net/blog/headless-builds/ happy headlessing :-)

Recently I ran into very interesting problem which I thought would take me just a couple of minutes to solve: protecting Apache CXF (current release 3.0.1)/ JAX-RS REST services with Spring Security (current stable version 3.2.5) in the application running inside embedded Jetty container (current release 9.2). At the end, it turns out to be very easy, once you understand how things work together and known subtle intrinsic details. This blog post will try to reveal that. Our example application is going to expose a simple JAX-RS / REST service to manage people. However, we do not want everyone to be allowed to do that so the HTTP basic authentication will be required in order to access our endpoint, deployed at http://localhost:8080/api/rest/people. Let us take a look on thePeopleRestService class: package com.example.rs; import javax.json.Json; import javax.json.JsonArray; import javax.ws.rs.GET; import javax.ws.rs.Path; import javax.ws.rs.Produces; @Path( "/people" ) public class PeopleRestService { @Produces( { "application/json" } ) @GET public JsonArray getPeople() { return Json.createArrayBuilder() .add( Json.createObjectBuilder() .add( "firstName", "Tom" ) .add( "lastName", "Tommyknocker" ) .add( "email", "[email protected]" ) ) .build(); } } As you can see in the snippet above, nothing is pointing out to the fact that this REST service is secured, just couple of familiar JAX-RS annotations. Now, let us declare the desired security configuration following excellent Spring Security documentation. There are many ways to configure Spring Security but we are going to show off two of them: using in-memory authentication and using user details service, both built on top of WebSecurityConfigurerAdapter. Let us start with in-memory authentication as it is the simplest one: package com.example.config; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.context.annotation.Configuration; import org.springframework.security.config.annotation.authentication.builders.AuthenticationManagerBuilder; import org.springframework.security.config.annotation.method.configuration.EnableGlobalMethodSecurity; import org.springframework.security.config.annotation.web.builders.HttpSecurity; import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity; import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter; import org.springframework.security.config.http.SessionCreationPolicy; @Configuration @EnableWebSecurity @EnableGlobalMethodSecurity( securedEnabled = true ) public class InMemorySecurityConfig extends WebSecurityConfigurerAdapter { @Autowired public void configureGlobal(AuthenticationManagerBuilder auth) throws Exception { auth.inMemoryAuthentication() .withUser( "user" ).password( "password" ).roles( "USER" ).and() .withUser( "admin" ).password( "password" ).roles( "USER", "ADMIN" ); } @Override protected void configure( HttpSecurity http ) throws Exception { http.httpBasic().and() .sessionManagement().sessionCreationPolicy( SessionCreationPolicy.STATELESS ).and() .authorizeRequests().antMatchers("/**").hasRole( "USER" ); } } In the snippet above there two users defined: user with the role USER and admin with the roles USER,ADMIN. We also protecting all URLs (/**) by setting authorization policy to allow access only users with roleUSER. Being just a part of the application configuration, let us plug it into the AppConfig class using @Importannotation. package com.example.config; import java.util.Arrays; import javax.ws.rs.ext.RuntimeDelegate; import org.apache.cxf.bus.spring.SpringBus; import org.apache.cxf.endpoint.Server; import org.apache.cxf.jaxrs.JAXRSServerFactoryBean; import org.apache.cxf.jaxrs.provider.jsrjsonp.JsrJsonpProvider; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.context.annotation.DependsOn; import org.springframework.context.annotation.Import; import com.example.rs.JaxRsApiApplication; import com.example.rs.PeopleRestService; @Configuration @Import( InMemorySecurityConfig.class ) public class AppConfig { @Bean( destroyMethod = "shutdown" ) public SpringBus cxf() { return new SpringBus(); } @Bean @DependsOn ( "cxf" ) public Server jaxRsServer() { JAXRSServerFactoryBean factory = RuntimeDelegate.getInstance().createEndpoint( jaxRsApiApplication(), JAXRSServerFactoryBean.class ); factory.setServiceBeans( Arrays.< Object >asList( peopleRestService() ) ); factory.setAddress( factory.getAddress() ); factory.setProviders( Arrays.< Object >asList( new JsrJsonpProvider() ) ); return factory.create(); } @Bean public JaxRsApiApplication jaxRsApiApplication() { return new JaxRsApiApplication(); } @Bean public PeopleRestService peopleRestService() { return new PeopleRestService(); } } At this point we have all the pieces except the most interesting one: the code which runs embedded Jettyinstance and creates proper servlet mappings, listeners, passing down the configuration we have created. package com.example; import java.util.EnumSet; import javax.servlet.DispatcherType; import org.apache.cxf.transport.servlet.CXFServlet; import org.eclipse.jetty.server.Server; import org.eclipse.jetty.servlet.FilterHolder; import org.eclipse.jetty.servlet.ServletContextHandler; import org.eclipse.jetty.servlet.ServletHolder; import org.springframework.web.context.ContextLoaderListener; import org.springframework.web.context.support.AnnotationConfigWebApplicationContext; import org.springframework.web.filter.DelegatingFilterProxy; import com.example.config.AppConfig; public class Starter { public static void main( final String[] args ) throws Exception { Server server = new Server( 8080 ); // Register and map the dispatcher servlet final ServletHolder servletHolder = new ServletHolder( new CXFServlet() ); final ServletContextHandler context = new ServletContextHandler(); context.setContextPath( "/" ); context.addServlet( servletHolder, "/rest/*" ); context.addEventListener( new ContextLoaderListener() ); context.setInitParameter( "contextClass", AnnotationConfigWebApplicationContext.class.getName() ); context.setInitParameter( "contextConfigLocation", AppConfig.class.getName() ); // Add Spring Security Filter by the name context.addFilter( new FilterHolder( new DelegatingFilterProxy( "springSecurityFilterChain" ) ), "/*", EnumSet.allOf( DispatcherType.class ) ); server.setHandler( context ); server.start(); server.join(); } } Most of the code does not require any explanation except the the filter part. This is what I meant by subtle intrinsic detail: the DelegatingFilterProxy should be configured with the filter name which must be exactlyspringSecurityFilterChain, as Spring Security names it. With that, the security rules we have configured are going to apply to any JAX-RS service call (the security filter is executed before the Apache CXF servlet), requiring the full authentication. Let us quickly check that by building and running the project: mvn clean package java -jar target/jax-rs-2.0-spring-security-0.0.1-SNAPSHOT.jar Issuing the HTTP GET call without providing username and password does not succeed and returns HTTP status code 401. > curl -i http://localhost:8080/rest/api/people HTTP/1.1 401 Full authentication is required to access this resource WWW-Authenticate: Basic realm="Realm" Cache-Control: must-revalidate,no-cache,no-store Content-Type: text/html; charset=ISO-8859-1 Content-Length: 339 Server: Jetty(9.2.2.v20140723) The same HTTP GET call with username and password provided returns successful response (with some JSON generated by the server). > curl -i -u user:password http://localhost:8080/rest/api/people HTTP/1.1 200 OK Date: Sun, 28 Sep 2014 20:07:35 GMT Content-Type: application/json Content-Length: 65 Server: Jetty(9.2.2.v20140723) [{"firstName":"Tom","lastName":"Tommyknocker","email":"[email protected]"}] Excellent, it works like a charm! Turns out, it is really very easy. Also, as it was mentioned before, the in-memory authentication could be replaced with user details service, here is an example how it could be done: package com.example.config; import java.util.Arrays; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.security.config.annotation.authentication.builders.AuthenticationManagerBuilder; import org.springframework.security.config.annotation.method.configuration.EnableGlobalMethodSecurity; import org.springframework.security.config.annotation.web.builders.HttpSecurity; import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity; import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter; import org.springframework.security.config.http.SessionCreationPolicy; import org.springframework.security.core.authority.SimpleGrantedAuthority; import org.springframework.security.core.userdetails.User; import org.springframework.security.core.userdetails.UserDetails; import org.springframework.security.core.userdetails.UserDetailsService; import org.springframework.security.core.userdetails.UsernameNotFoundException; @Configuration @EnableWebSecurity @EnableGlobalMethodSecurity(securedEnabled = true) public class UserDetailsSecurityConfig extends WebSecurityConfigurerAdapter { @Autowired public void configureGlobal(AuthenticationManagerBuilder auth) throws Exception { auth.userDetailsService( userDetailsService() ); } @Bean public UserDetailsService userDetailsService() { return new UserDetailsService() { @Override public UserDetails loadUserByUsername( final String username ) throws UsernameNotFoundException { if( username.equals( "admin" ) ) { return new User( username, "password", true, true, true, true, Arrays.asList( new SimpleGrantedAuthority( "ROLE_USER" ), new SimpleGrantedAuthority( "ROLE_ADMIN" ) ) ); } else if ( username.equals( "user" ) ) { return new User( username, "password", true, true, true, true, Arrays.asList( new SimpleGrantedAuthority( "ROLE_USER" ) ) ); } return null; } }; } @Override protected void configure( HttpSecurity http ) throws Exception { http .httpBasic().and() .sessionManagement().sessionCreationPolicy( SessionCreationPolicy.STATELESS ).and() .authorizeRequests().antMatchers("/**").hasRole( "USER" ); } } Replacing the @Import( InMemorySecurityConfig.class ) with @Import( UserDetailsSecurityConfig.class ) in the AppConfig class leads to the same results, as both security configurations define the identical sets of users and their roles. I hope, this blog post will save you some time and gives a good starting point, as Apache CXF and Spring Security are getting along very well under Jetty umbrella! The complete source code is available on GitHub.

These are two concepts that I mix up occasionally - a WebApplicationInitializer and an ApplicationContextInitializer, and wanted to describe each of them to clarify them for myself. I have previously blogged about WebApplicationInitializerhere and here. It is relevant purely in a Servlet 3.0+ spec compliant servlet container and provides a hook to programmatically configure the servlet context. How does this help - you can have a web application without potentially any web.xml file, typically used in a Spring based web application to describe the root application context and the Spring web front controller called theDispatcherServlet. An example of using WebApplicationInitializer is the following: public class CustomWebAppInitializer extends AbstractAnnotationConfigDispatcherServletInitializer { @Override protected Class[] getRootConfigClasses() { return new Class[]{RootConfiguration.class}; } @Override protected Class[] getServletConfigClasses() { return new Class[]{MvcConfiguration.class}; } @Override protected String[] getServletMappings() { return new String[]{"/"}; } } Now, what is an ApplicationContextInitializer. It is essentially code that gets executed before the Spring application context gets completely created. A good use case for using an ApplicationContextInitializer would be to set a Spring environment profile programmatically, along these lines: public class DemoApplicationContextInitializer implements ApplicationContextInitializer { @Override public void initialize(ConfigurableApplicationContext ac) { ConfigurableEnvironment appEnvironment = ac.getEnvironment(); appEnvironment.addActiveProfile("demo"); } } If you have a Spring-Boot based application then registering an ApplicationContextInitializer is fairly straightforward: @Configuration @EnableAutoConfiguration @ComponentScan public class SampleWebApplication { public static void main(String[] args) { new SpringApplicationBuilder(SampleWebApplication.class) .initializers(new DemoApplicationContextInitializer()) .run(args); } } For a non Spring-Boot Spring application though, it is a little more tricky, if it is a programmatic configuration of web.xml, then the configuration is along these lines: public class CustomWebAppInitializer implements WebApplicationInitializer { @Override public void onStartup(ServletContext container) { AnnotationConfigWebApplicationContext rootContext = new AnnotationConfigWebApplicationContext(); rootContext.register(RootConfiguration.class); ContextLoaderListener contextLoaderListener = new ContextLoaderListener(rootContext); container.addListener(contextLoaderListener); container.setInitParameter("contextInitializerClasses", "mvctest.web.DemoApplicationContextInitializer"); AnnotationConfigWebApplicationContext webContext = new AnnotationConfigWebApplicationContext(); webContext.register(MvcConfiguration.class); DispatcherServlet dispatcherServlet = new DispatcherServlet(webContext); ServletRegistration.Dynamic dispatcher = container.addServlet("dispatcher", dispatcherServlet); dispatcher.addMapping("/"); } } If it a normal web.xml configuration then the initializer can be specified this way: contextInitializerClasses com.myapp.spring.SpringContextProfileInit org.springframework.web.context.ContextLoaderListener So to conclude, except for the Initializer suffix, both WebApplicationInitializer and ApplicationContextInitializer serve fairly different purposes. Whereas the WebApplicationInitializer is used by a Servlet Container at startup of the web application and provides a way for programmatic creating a web application(replacement for a web.xml file), ApplicationContextInitializer provides a hook to configure the Spring application context before it gets fully created.

this article describes steps required to configure your eclipse for sonarqube such that developers are not required to leave the eclipse ide to manage their source code quality. please feel free to comment/suggest if i missed to mention one or more important points. also, sorry for the typos. following are the key points described later in this article: installing & configuraing sonarqube in eclipse analyzing code using sonarqube installing & configuraing sonarqube in eclipse follow the steps given on following pages to install and configure sonarqube in your eclipse ide. the page on installing sonarqube in eclipse consists of steps required to install sonarqube in the ide. once downloaded, it would prompt to restart the eclipse ide. for proceeding ahead, you must restart the eclipse ide. the page on configuring sonarqube in eclipse consists of steps required to configure eclipse for sonarqube. the key thing to note is the fact that as you click on preferences > sonarqube > servers , you see the default server entry for http://localhost:9000. initially, as per instruction page, seeing the default entry, i went ahead to next step for linking the project to sonarqube server and run the analysis. however, it throw the error such as unknowb version of sonarqube server . after a little research, i figured out that the error was thrown as the sonarqube server was not reachable although i saw it configured as http://localhost:9000. the solution is to go to preferences > sonarqube > servers , click “edit” button and you would see sonarqube server url, username and password. the key is to give username and password and run the analysis once again. analyzing code using sonarqube once you are done with installation and configuration of sonarqube server in eclipse ide, for code analysis, all you need is right click on your project and click sonarqube > analyze and that is it. the violations would appear in sonarqube analysis as shown in the screenshot below. sonarqube analysis in eclipse however, do note that these issues may not appear if you try to access on the browser. for that to happen, you need to once again run “sonar-runner” from the project root.

the gnu arm eclipse plugins from liviu already offer several built-in actions which can be performed at the end of a build: creating flash image , create listing file and printing the code and data size: gnu arm eclipse extra post build steps but what if i need different things, or even more things? post-build steps for this there is the ‘post-build steps’ settings i can use: that command is executed at the end of the build: print size post-build step :!: the post build step is only executed if sources files have been compiled and linked. if you want to enforce that there is always a ‘true’ post build, then you need to delete some files in the pre-build step to enforce a compilation and a link phase. multiple post-build steps but what i need more than one action in the post-build step? i could call a batch or script file, but this is probably an overkill in too many cases, and adds a dependency to that script file. a better approach is to directly execute multiple commands as post-build step. unfortunately, the documentation found about the post-build step with a web-search is misleading (e.g. in the eclipse luna documentation ): “command: specifies one or more commands to execute immediately after the execution of the build. use semicolons to separate multiple commands.” unfortunately, semicolons is plain wrong (at least did not work for me) :-(. the solution is to use ‘ & ‘ (ampersand) to separate multiple commands on windows : :idea: on linux, use the ‘;’ to separate commands as noted in the documentation/help, and use ‘&’ on windows. unfortunately, this makes project not cross-platform. multiple post-build commands and this works for me, at least under windows 7 :-).

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this tip sounds very basic, but still: i get asked about this about once a week. so it must be something non-obvious in eclipse then ;-): how to add existing files to an eclipse project. as with many things in eclipse, there is not a single way to do something. there are two basic ways to do this: import drag & drop copy & paste the first is the ‘official’ way in eclipse, the other two are much faster and easier :-). 1. import to import one or multiple files, select the folder/project where i want to add the files, then use the menu file > import : menu file import alternatively, i can use the context menu: import context menu then use general > file system : import from file system in the next dialog, i can browse for the files and select them to be added: importing files from filesystem 2. drag & drop while the ‘import’ method is fine, i rarely use it: too many clicks! a easier way (at least under windows) is to drag & drop the files from the windows explorer: drag and drop to add files 3. copy & paste the third way is even easier: select the files i want to add in the explorer/file manager, and copy them ( ctrl-c on windows) paste them in the project/folder in eclipse ( ctrl-v on windows) that last method does not advanced options like if i want to link to the files, see “ link to files and folders in eclipse “, but is definitely the fastest and easiest way. happy adding :-)

eclipse projects have the nice features that they can link to files and folders: so instead of having the physical file, it is just a pointer to a file. this is very cool as that way i can point to shared files, or keep files in a common place referenced from projects, and so on. linked folder and file in eclipse as with most things in eclipse, there is not a single way how to do things. so i’m showing in this post several ways how to link to files and folders. creating a new link select the folder/project where to create a link to a file. use the context menu with n ew > file (or the menu file > new > other > general > file ): new file that opens a dialog to create a new file. i can select which project/folder i want to use for this: new file dialog next, click on ‘advanced’, enable ‘link to file in the file system’ and browse to the file you want to link to: link to file this will set the link to the file: specified link to file as an absolute path (c:\….) is probably not really what you want, there are eclipse path variables you can use: path variables :idea: note that these are eclipse path variables (not eclipse build variables), see “ eclipse build variables “. to use the path variable for the link, use the ‘extend…’ button and then select the file, then press ok: extending path variable this now uses a path variable for that link. note that it shows as well to which file it resolves: resolved path variable for linked file press finish, and the link will be created. note the small ‘arrow’ in the icon (see “ icon and label decorators in eclipse “) to show a linked file: linked file modifying a link if you right-click on that linked file and select ‘properties’ of it, you can see that it is really a linked file, with the link information, and you can change/edit that link any time: linked file properties linked folder as for link to files, its possible to create ‘link to folders’. it works the same way: select the folder, then use file > new > folder: creating new folder use default location : this creates a normal folder. virtual folder : this does not create a physical folder, but a virtual ‘container’ where i can place links or other virtual folders. this is useful to organize links and virtual folders, without the need for a physical folder. linked folder : like linked files, this links to a folder. :idea: the cool thing about linked (source) folders is: when i add new files to that folder where it links to, the projects with that linked folder to it will ‘see’ the extra files too, and that way new files are automatically added to the project. i do this many times, and it is like a ‘library’ folder for me: i can add a new source file to that ‘library’ folder, and every project linking to that folder will automatically have it added. :-) deleting links linked files and linked folders can be deleted from the project too. in that case, the destination of the link is *not* deleted, only the link: deleting a link to a folder using drag & drop as mentioned at the beginning: there are multiple ways to do the same thing in eclipse. instead using the top menu, or using the context menu, i can use drag & drop. to create links, i need to hold the ctrl key: drag and drop with ctrl pressed to create a link :idea: notice that during the drag&drop with ctrl key pressed the icon gets a ‘+’ to show copy/linking mode. when i drop the file: i get the usual choices how i want to create the link: link to files and folders dialog drag&drop of files and folders do not work inside eclipse. what works as well under windows is to drag&drop a file or folder from the windows explorer :-). summary links to files and folders are a cool thing in eclipse, and they can be created with menus or even simpler with drag&drop. this is not limited to inside eclipse: i can drag&drop from outside with the windows explorer and that way can link to files and folders everywhere :-) happy linking :-)

in “ semihosting with kinetis design studio ” i used printf() to exchange text and data between the target board and the host using the debug connection. kinetis design studio (kds) has that semihosting baked into its libraries. what about if using the gnu arm embedded (launchpad) tools and libraries (see “ switching arm gnu tool chain and libraries in kinetis design studio “)? actually it requires two more steps, but is very easy too. semihosting output there are three things to be in place to use semihosting with the gnu arm embedded (launchpad) libraries: option in the gnu linker settings enabling semihosting in the debugger settings initializing the gnu libraries linker option to enable semihosting for the gnu arm embedded ( launchpad ) libraries, i need to add --specs=rdimon.specs to the linker options: linker option to enable semihosting in case i’m using newlib-nano and want to use printf() and/or scanf() with floating point support, i need to pull in some symbols explicitly with the linker options ‘u': -u _scanf_float -u _printf_float debugger settings in the gnu arm eclipse plugins, i need to enable semihosting. segger j-link for segger j-link, i enable the console in the launch configuration: allocated semihosting console for segger additionally i enable semihosting options in the startup options of the debugger: enabled semihosting in the startup options for segger p&e multilink for p&e the following settings are used: semihosting settings for pne settings for openocd the following settings are used for openocd: openocd semihosting settings initializing the gnu libraries if you would now try to use semihosting with running the debugger, you probably will get error messages like this (e.g. from segger j-link): warning: semihosting command sys_flen failed. handle is 0. warning: semihosting command sys_write failed. handle is 0. warning: semihosting command sys_write failed. handle is 0. warning: semihosting command sys_write failed. handle is 0. the reason is that the semihosting needs to be enabled by the application. i need to call initialise_monitor_handles() before i’m using printf() : 1 2 3 4 5 6 7 8 extern void initialise_monitor_handles( void ); /* prototype */ int main( void ) { initialise_monitor_handles(); /* initialize handles */ for (;;) { printf ( "hello world!\r\n" ); } } with this, i can use printf() and scanf() through a debugger connection. semihosting printf output summary while i don’t like printf() for many reasons, sometimes it is useful to exchange data with the host. using semihosting no physical connection is required, as the communication goes through the debugger. it is somewhat intrusive, and adds code and data overhead, but the gnu arm embedded (launchpad) libraries (both newlib and newlib-nano) have semihosting built-in. it is a matter to enable it in the linker and debugger settings, and to initialize the handles in the application. happy semihosting :-)