JAX-RS Test Showcase

JAX-RS is a popular JavaEE standard to create RESTful endpoints in Java easily. However, it is not always clear for new learners how to test those endpoints properly.

Table of Contents

• Project setup
  • JSON-P, JSON-B and JAX-RS implementations
  • Web-API and Web-Impl projects
  • Test projects
• Built with Toolchains

Project setup

JSON-P, JSON-B and JAX-RS implementations

As JAX-RS is only a standard and is usually used in conjunction with JSON, there are unsurprisingly multiple implementations for those standards available.

Table 1. JAX-RS implementations

Vendor	Library Name	License
Apache Foundation	Apache CXF	Apache License 2.0
Eclipse Foundation	Eclipse Jersey (reference implementation)	Eclipse Public License 2.0
JBoss by RedHat	JBoss restEasy	Apache License 2.0

You can also switch the JSON-B and JSON-P implementations. However, both of them can only be switched at the same time.

Table 2. JSON implementations

Vendor	Library Name	License
Apache Foundation	Apache Johnzon	Apache License 2.0
Eclipse Foundation	Eclipse Yasson (reference implementation)	Eclipse Public License 2.0

Where useful, tests are duplicated to be run on all combinations of implementations.

Web-API and Web-Impl projects

First we need an endpoint to test. For this reason, there are the modules web/rest-api and web/rest-impl. Please note that it is often not required to have a separate api project. This is YAGNI (you ain’t gonna need it) in most cases. However, separating the API from the implementation allows you (or others) to re-use the jar file from the API project for the Proxy-based API.

Test projects

Table 3. System tests

module path	JAX-RS impl	JSON impl
systemtests/cxf-localtp-johnzon	Apache CXF	Apache Johnzon
systemtests/jersey-grizzly2-johnzon	Eclipse Jersey	Apache Johnzon
systemtests/jersey-grizzly2-yasson	Eclipse Jersey	Eclipse Yasson

Table 4. Integration tests

module path	Container/App server

Built with Toolchains

This project makes use of both the maven-toolchain-plugin to accept IBM Semeru Runtimes for tests and the toolchains-maven-plugin for downloading the JDK first (if required).