Question

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.

So I wish a build to fail if (my) java program run as a step within the build decides that the build must fail.

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.

Is there a nice way of ant failing the build if a java step decides it should?

Answer 1

For the <java> task, there is an attribute failonerror. If you set it to yes (or true), the build will fail if the process returned anything else than 0.

The problem is that for returning some value from a java call, this call must System.exit(value). For it to not kill your ant, you also need to provide fork=true to run in a new JVM.

So, the java call could look like this:

<java jar="..."
      fork="yes"
      failonerror="yes">
</java>

Of course, you could also have your Java program implement the Ant Task API and load/call it as a proper ant task. Then it can itself decide what to do (and will be more configurable, too).