public  void execute(Project project) throws BuildException 
{
        final String classname = javaCommand.getExecutable();
        AntClassLoader loader = null;
        try {
            if (sysProperties != null) {
                sysProperties.setSystem();
            }
            Class target = null;
            try {
                if (classpath == null) {
                    target = Class.forName(classname);
                } else {
                    loader = project.createClassLoader(classpath);
                    loader.setParent(project.getCoreLoader());
                    loader.setParentFirst(false);
                    loader.addJavaLibraries();
                    loader.setIsolated(true);
                    loader.setThreadContextLoader();
                    loader.forceLoadClass(classname);
                    target = Class.forName(classname, true, loader);
                }
            } catch (ClassNotFoundException e) {
                throw new BuildException("Could not find " + classname + "."
                                         + " Make sure you have it in your"
                                         + " classpath");
            }
            main = target.getMethod("main", new Class[] {String[].class});
            if (main == null) {
                throw new BuildException("Could not find main() method in "
                                         + classname);
            }
            if ((main.getModifiers() & Modifier.STATIC) == 0) {
                throw new BuildException("main() method in " + classname
                    + " is not declared static");
            }
            if (timeout == null) {
                run();
            } else {
                thread = new Thread(this, "ExecuteJava");
                Task currentThreadTask
                    = project.getThreadTask(Thread.currentThread());
                // XXX is the following really necessary? it is in the same thread group...
                project.registerThreadTask(thread, currentThreadTask);
                // if we run into a timeout, the run-away thread shall not
                // make the VM run forever - if no timeout occurs, Ant's
                // main thread will still be there to let the new thread
                // finish
                thread.setDaemon(true);
                Watchdog w = new Watchdog(timeout.longValue());
                w.addTimeoutObserver(this);
                synchronized (this) {
                    thread.start();
                    w.start();
                    try {
                        wait();
                    } catch (InterruptedException e) {
                        // ignore
                    }
                    if (timedOut) {
                        project.log("Timeout: sub-process interrupted",
                                    Project.MSG_WARN);
                    } else {
                        thread = null;
                        w.stop();
                    }
                }
            }
            if (caught != null) {
                throw caught;
            }
        } catch (BuildException e) {
            throw e;
        } catch (SecurityException e) {
            throw e;
        } catch (ThreadDeath e) {
            // XXX could perhaps also call thread.stop(); not sure if anyone cares
            throw e;
        } catch (Throwable e) {
            throw new BuildException(e);
        } finally {
            if (loader != null) {
                loader.resetThreadContextLoader();
                loader.cleanup();
                loader = null;
            }
            if (sysProperties != null) {
                sysProperties.restoreSystem();
            }
        }
}

Execute the Java class against the specified Ant Project.

 public int fork(ProjectComponent pc) throws BuildException 
{
        CommandlineJava cmdl = new CommandlineJava();
        cmdl.setClassname(javaCommand.getExecutable());
        String[] args = javaCommand.getArguments();
        for (int i = 0; i <  args.length; i++) {
            cmdl.createArgument().setValue(args[i]);
        }
        if (classpath != null) {
            cmdl.createClasspath(pc.getProject()).append(classpath);
        }
        if (sysProperties != null) {
            cmdl.addSysproperties(sysProperties);
        }
        Redirector redirector = new Redirector(pc);
        Execute exe
            = new Execute(redirector.createHandler(),
                          timeout == null
                          ? null
                          : new ExecuteWatchdog(timeout.longValue()));
        exe.setAntRun(pc.getProject());
        if (Os.isFamily("openvms")) {
            setupCommandLineForVMS(exe, cmdl.getCommandline());
        } else {
            exe.setCommandline(cmdl.getCommandline());
        }
        try {
            int rc = exe.execute();
            redirector.complete();
            return rc;
        } catch (IOException e) {
            throw new BuildException(e);
        } finally {
            timedOut = exe.killedProcess();
        }
}

Run the Java command in a separate VM, this does not give you the full flexibility of the Java task, but may be enough for simple needs.

 public synchronized boolean killedProcess() 
{
        return timedOut;
}

Get whether the process was killed.

 public  void run() 
{
        final Object[] argument = {javaCommand.getArguments()};
        try {
            if (perm != null) {
                perm.setSecurityManager();
            }
            main.invoke(null, argument);
        } catch (InvocationTargetException e) {
            Throwable t = e.getTargetException();
            if (!(t instanceof InterruptedException)) {
                caught = t;
            } /* else { swallow, probably due to timeout } */
        } catch (Throwable t) {
            caught = t;
        } finally {
            if (perm != null) {
                perm.restoreSecurityManager();
            }
            synchronized (this) {
                notifyAll();
            }
        }
}

Run this ExecuteJava in a Thread.

 public  void setClasspath(Path p) 
{
        classpath = p;
}

Set the classpath to be used when running the Java class.

 public  void setJavaCommand(Commandline javaCommand) 
{
                         
        this.javaCommand = javaCommand;
}

Set the Java "command" for this ExecuteJava.

 public  void setOutput(PrintStream out) 
{

}

Set the stream to which all output (System.out as well as System.err) will be written.

 public  void setPermissions(Permissions permissions) 
{
        perm = permissions;
}

Set the permissions for the application run.

 public  void setSystemProperties(CommandlineJava.SysProperties s) 
{
        sysProperties = s;
}

Set the system properties to use when running the Java class.

 public  void setTimeout(Long timeout) 
{
        this.timeout = timeout;
}

Set the timeout for this ExecuteJava.

 public static  void setupCommandLineForVMS(Execute exe,
    String[] command) 
{
        //Use the VM launcher instead of shell launcher on VMS
        exe.setVMLauncher(true);
        File vmsJavaOptionFile = null;
        try {
            String [] args = new String[command.length - 1];
            System.arraycopy(command, 1, args, 0, command.length - 1);
            vmsJavaOptionFile = JavaEnvUtils.createVmsJavaOptionFile(args);
            //we mark the file to be deleted on exit.
            //the alternative would be to cache the filename and delete
            //after execution finished, which is much better for long-lived runtimes
            //though spawning complicates things...
            vmsJavaOptionFile.deleteOnExit();
            String [] vmsCmd = {command[0], "-V", vmsJavaOptionFile.getPath()};
            exe.setCommandline(vmsCmd);
        } catch (IOException e) {
            throw new BuildException("Failed to create a temporary file for \"-V\" switch");
        }
}

On VMS platform, we need to create a special java options file containing the arguments and classpath for the java command. The special file is supported by the "-V" switch on the VMS JVM.

 public synchronized  void timeoutOccured(Watchdog w) 
{
        if (thread != null) {
            timedOut = true;
            thread.interrupt();
        }
        notifyAll();
}

Mark timeout as having occurred.