Tech

JAX-RS 2.0 aka JSR 339 not also specifies the API to build up a RESTful webservice but also enhances the client side API to ease up the process of writing a client for a REST service. In the following tutorial we’re building up a client for a ready-to-play REST service and explore the different new options e.g. how to handle requests in a synchronous or asynchronous way, how to add callback handlers for a request, how to specify invocation targets to build up requests for a later execution or how to filter the client-server communication using client request filters and client response filters. ...

Vert.x is a modern, lightweight framework to build high performance applications running on the Java Virtual Machine. The framework is polyglot so that you’re able to write your application in Java, Groovy, Ruby, Python or even JavaScript. In addition it offers a nice component system, an actor-like concurrency model a distributed event bus and an elegant API to create scalable applications in no time. In the following tutorial we’re going to build a websocket chat by creating a HTTP server and the websocket server using Vert.x, Java and Maven. ...

MongoDB is matured, document-oriented, cross-platform NoSQL database system with drivers available for a bunch of different programming languages. In the following short examples I’m going to write some integration tests for MongoDB using the MongoDB Java driver and the Flapdoodle library to create an embedded MongoDB instance for testing. We’re going to write tests for a simple persist-and-query scenarion and for a map-reduce function and in addition I’m going to show how to bind the start and stop of a MongoDB instance to a Maven goal using the embedmongo-maven-plugin. ...

Many articles have been written about JSR 335 aka Lambda Expressions for the JavaTM Programming Language but I like to try new things out for myself and that’s why I’d like to share my snippets here. Figure 1. Lambda Hacking using the NetBeans Developer Version Setup JDK and IDE It takes just some short steps to setup your environment … Download and install the Java 8 JDK with lambda support Download and install the NetBeans IDE Development version Configure NetBeans to use the Java 8 JDK (> Manage Platforms…) ...

Having tried a bunch of workflow engines and business processing management platforms I now have given the Activiti framework a try. I immediately liked the good test support using annotations and jUnit test rules, a straight API and the good Eclipse IDE integration as well as I liked the Activiti Explorer and the Activiti REST Application and the feeling to achieve quick results with less effort when using this framework. ...

The Templating Maven Plugin looks useful if one needs to copy and to filter source files in a project e.g. to add property values from the build environment to a class. For a short demonstration I’ve added the following short snippet. Dependencies Only one dependency needed .. simply add the following snippet to your pom.xml <build> <plugins> <plugin> <groupId>org.codehaus.mojo</groupId> <artifactId>templating-maven-plugin</artifactId> <version>1.0-alpha-3</version> <executions> <execution> <id>filter-src</id> <goals> <goal>filter-sources</goal> </goals> </execution> </executions> </plugin> </plugins> </build> ...

Java EE 7 is out now and so I was curious to play around with the new specifications and APIs from in this technology stack. That’s why I didn’t hesitate to add yet another websocket-chat tutorial to the existing ones on the internet in favour of gathering some experience with this technology and a possible integration using a GlassFish 4 server, the new Java API for JSON Processing for data serialization combined with custom websocket encoders/decoders and finally adding some Bootstrap and jQuery on the client side. ...

Recently I needed to control an embedded web container from a Java application and I wanted to see how this could be achieved using an embedded instance of either Tomcat or Jetty here. In the following short examples I would like to show how to embed both servers in an application in no time using Gradle or Maven as build tool. Dependencies We just need to add the web container libraries to our project here .. I’ve added the build config for Gradle and Maven here… ...

Feature flags are a common technique, often combined with continuous deployment and delivery and they allow us to rollback a specific feature, to create A/B tests or to rollout a specific feature for a specific test group, a specific amount of users or dedicated systems. In the following short examples I’d like you to demonstrate how easy it is to implement feature flags with the Togglz framework with a few steps in a Java EE environment. ...

It’s been a long way for Java FX from the days of the F3 project the current release 2.2. Today there are many options how to create a Java FX application .. you may be using Java, Scala, Groovy or Visage, you may create your application in a programmatic way using the comfortable integrated builders or you may create your views using XML layouts and easy data-bindings with a few annotations. ...