Eclipse Cookbook

5.1. Installing JUnit

Problem

You want to install JUnit so that you can use it in Eclipse.

Solution

Add junit.jar to your project’s classpath.

Discussion

In Eclipse 2.1.x and in the current versions of Eclipse 3.0, you can find junit.jar in eclipse/plugins/org.junit_3.8.1/junit.jar.

If you’re going to be using JUnit regularly, it helps to create a new classpath variable; I named mine JUNIT. Select Window→ Preferences→ Java→ Classpath Variables, and click the New button to open the New Variable Entry dialog; now enter the name of the new variable—JUNIT—and the path to junit.jar.

You also can let Eclipse know where JUnit’s source code is; this is a useful step for debugging, giving Eclipse access to a JAR file’s code so that it can display it as needed. Note that this is an optional step because you don’t need to see the JUnit code. To create a new variable for the JUnit source, which we’ll call JUNIT_SRC, connect that variable to eclipse/plugins/org.eclipse.jdt.source_x.y.z/src/org.junit_3.8.1/junitsrc.zip, where x.y.z is your version of Eclipse. Then right-click your project, click Properties, click the Java Build Path node and the Libraries tab, and then expand the node for the JUNIT entry, as shown in Figure 5-1.

Figure 5-1. Making source code accessible to Eclipse

When you expand a JAR file’s node, you can specify where to find the associated source code and Javadoc. To use JUNIT_SRC