title: Making Java step in Ant script fail the build
body: <p>Please excuse if the question is dumb, I'm only 2nd day on Ant and Java hacking together some CI solution with next to no knowledge of Ant or Java.</p>
  
  <p>So I wish a build to fail if (my) java program run as a step within the build decides that the build must fail.</p>
  
  <p>I thought of just throwing an unhandled exception in the Java program or using System.exit() to shut down the JVM but they seem quite nasty.</p>
  
  <p>Is there a nice way of ant failing the build if a java step decides it should?</p>