A sample Java test runner using annotations

marco — Sun, 19 Apr 2009 19:23:00 +0000

I have found this toy code on java.sun.com that describes how Java annotations could be used to write a simple Test runner. This script gets as argument the name of a class and tries to execute all the methods of that class that are annotated as @Test.
The interesting aspect of this code is that is shows clearly how annotations can be used to execute/manipulate source code.

import java.lang.reflect.*;
 
public class RunTests {
  public static void main(String[] args) throws Exception {
     int passed = 0, failed = 0;
     for (Method m : Class.forName(args[0]).getMethods()) {
        if (m.isAnnotationPresent(Test.class)) {
           try {
              m.invoke(null);
              passed++;
           } catch (Throwable ex) {
              System.out.printf(
                "Test %s failed: %s %n",
                m,
                ex.getCause()
              );
              failed++;
           }
        }
     }
     System.out.printf("Passed: %d, Failed %d%n", passed, failed);
  }
}

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A sample Java test runner using annotations