The RESTful API can be implemented in Java in a number of ways: you can use Spring, JAX-RS, or just write your own servlets if you’re good and brave enough.
Working with JAX-WS Web Services
Numerous platforms are available on the market for developing web services based on the Java platform. However, most of these platforms conform to the JAX-WS specification (JSR-000224).
Transition from JUNIT 3 to JUNIT 4
The migration of these unit tests to JUnit 4, however, has been rather slow. Part of the reason for this is the slow transition from JDK 1.4.x to Java 5 (or later).