Performance Testing a Multiuser Web Application with JMeter and Maven

When there is the need to create load tests or performance tests for an application, Apache JMeter is a handy tool and set up with ease. In the following short tutorial I’d like to demonstrate how to configure JMeter to log into a Java EE web application with multiple users specified in a CSV file, how to generate some basic reports and how to integrate JMeter into a mavenized build using the JMeter Maven Plugin. ...

January 18, 2015 · 7 min · 1327 words · Micha Kops

Marrying Java EE and BDD with Cucumber, Arquillian and Cukespace

Having written about the basics of using Cucumber in a Java project in my last blog article, I now would like to demonstrate how to use a similar setup in a Java EE web project with Arquillian and the Cukespace library. In the following tutorial, we’re going to write a full Java EE web application and add BDD-style tests to the project so that we’re able to test our business layer on the one hand and the user interface on the other hand using Arquillian Drone and Selenium. ...

January 7, 2015 · 11 min · 2175 words · Micha Kops

Java EE: Setting up and Testing Form-Based JDBC Authentication with Arquillian and Maven

Especially when it comes to testing, setting up a decent environment for a secured Java EE web application isn’t always an easy thing to do. In the following tutorial I’d like to demonstrate how to create a secured web application using form-based authentication and a JDBC realm to fetch users and roles and how to run the application in an embedded container for testing and development. Additionally I’d like to show how to write and run integration tests to verify the security setup using a setup of Maven, Embedded GlassFish, Arquillian, jUnit and rest-assured. ...

December 21, 2014 · 14 min · 2822 words · Micha Kops

Creating different Websocket Chat Clients in Java

Having written two articles about different websocket based chat server implementations in Java, I was recently asked how an implementation of the client side would look like in Java. That’s why I added this article to demonstrate how to create a websocket chat client applications within a few steps with the Java API for Websocket. In the following tutorial, we’re going to write a text-based chat client for the console first and afterwards we’re going to program a chat client with a graphical user interface, implemented in JavaFX. ...

November 9, 2014 · 10 min · 1937 words · Micha Kops

JAX-RS Server API Snippets

Because a lot of my current projects are using JAX-RS in different versions I’d like to write down and share some frequently used snippets for implementing RESTful web-services with the JAX-RS specification here. Using RegEx in Path Expressions Sometimes we need to extract multiple parameters from a path expression e.g. in the following example where year, month and day are fragments if the path. @GET @Path("/orders/{year:\\d{4}}-{month:\\d{2}}-{day:\\d{2}}") @Produces(MediaType.TEXT_PLAIN) public Response getOrders(@PathParam("year") final int year, @PathParam("month") final int month, @PathParam("day") final int day) { return Response.ok("Year: " + year + ", month: " + month + ", day: " + day).build(); } ...

September 28, 2014 · 5 min · 924 words · Micha Kops

Java EE 7 JMX Reports with Yammer Metrics

There are several ways to aggregate and report application performance indicators in a Java application. One common way here is to use Java Management Extensions (JMX) and MBeans. The Yammer Metrics Library eases this task for us and simplifies the aggregation of different reports. In the following tutorial, we’re going to set up a full Java EE 7 web application by the help of Maven archetypes and we’re running the application on WildFly application server that is downloaded and configured completely by the WildFly Maven Plugin. ...

August 26, 2014 · 10 min · 2117 words · Micha Kops

Java EE 7 Database Migrations with Liquibase and WildFly

I have written about other database migration frameworks before but in this article I’d like to cover the Liquibase framework in combination with WildFly as Java EE 7 compatible application server. In the following tutorial, we’re going to write a full Java EE 7 book store application with a few steps and with Liquibase on board to create the database structure and insert example data into the database. Thanks to the WildFly Maven Plug-in we even do not need to download and configure the application server but let Maven and the plug-in do the work for us. ...

July 31, 2014 · 9 min · 1771 words · Micha Kops

Java EE: Logging User Interaction the Aspect-Oriented Way using Interceptors

Using dependency injection and aspect-oriented mechanisms like interceptors allow us to separate cross-cutting-concerns in our Java enterprise application, to control global aspects of our application and to avoid boilerplate code. In the following short tutorial we’re going to create an aspect-oriented logger to protocol the initiating user, class and method called and the parameters passed to the method and finally we’re adding this interceptor to a sample RESTful web-service by adding a simple annotation. ...

May 26, 2014 · 6 min · 1275 words · Micha Kops

Creating a Chat Application using Java EE 7, Websockets and GlassFish 4

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. ...

August 13, 2013 · 8 min · 1591 words · Micha Kops

Handling Feature Flags in a Java EE Application using Togglz

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. ...

June 26, 2013 · 6 min · 1103 words · Micha Kops