Hi fellow Ant'ers.
I originally started reading this list because I had problems with
blocking tasks when
using Ant, unfortunatly there seems like more have the same problem.
This is my first post and my solution to this problem.
I have modified code from Apache's Cactus-project to start a blocking task
(a server for example) and fork it of in a thread so Ant can continue with
other task.
Hope this helps. /Marcus
This i how my solution looks like in the build.xml-file:
--------%<-----[build.xml]----------------
<taskdef name="startServer" classname="org.myorg.StartServerTask"
classpath="${classpath}"/>
<target name="BlockingTask">
<exec dir="C:\Server_dir" executable="cmd.exe">
<arg line="/c start server.cmd"/>
</exec>
</target>
<target name="startServerAsync">
<startServer startTarget="BlockingTask"/>
</target>
--------%<-----[build.xml]----------------
--------%<-----[StartServerTask.java]----------------
package org.myorg;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.Task;
/**
* An Ant Task that does the following :
*
* create a java thread,
*
* start another Ant target in that thread. This target must be a
* blocking target.
*
*
*/
public class StartServerTask extends Task {
/**
* Helper class
*/
private StartServerHelper helper;
/**
* Initialization
*/
public void init() {
this.helper = new StartServerHelper(this);
}
/**
* @see Task#execute()
*/
public void execute() throws BuildException {
this.helper.execute();
}
/**
* Ant will automatically call this method when the "startTarget"
attribute
* of our task is used.
*
* @param theStartTarget the Ant target to call
*/
public void setStartTarget(String theStartTarget) {
this.helper.setStartTarget(theStartTarget);
}
}
--------%<-----[StartServerTask.java]-----------
--------%<-----[StartServerHelper.java]-----------
package org.myorg;;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.Task;
import org.apache.tools.ant.taskdefs.CallTarget;
/**
* A helper class for an Ant Task that does the following :
*
* create a java thread,
*
* start another Ant target in that thread. This target must be a
* blocking target.
*
*
*/
public class StartServerHelper implements Runnable {
/**
* The Ant target name that will start the blocking target.
*/
private String startTarget;
/**
* The tasks that wraps around this helper class
*/
private Task task;
/**
* @param theTask the Ant task that is calling this helper
*/
public StartServerHelper(Task theTask) {
this.task = theTask;
}
/**
* @see Task#execute()
*/
public void execute() throws BuildException {
// Verify that a start target has been specified
if (this.startTarget == null) {
throw new BuildException("A startTarget Ant target name must "
+
"be specified");
}
// Call the target in another thread. The called
// target must be blocking.
Thread thread = new Thread(this);
thread.start();
// We're done ... Ant will continue processing other tasks
}
/**
* The thread that calls the Ant target that starts, for example, a
server.
* Must be a blocking target.
*/
public void run() {
// Call the Ant target using the "antcall" task.
CallTarget callee;
callee = (CallTarget)
(this.task.getProject().createTask("antcall"));
callee.setOwningTarget(this.task.getOwningTarget());
callee.setTaskName(this.task.getTaskName());
callee.setLocation(this.task.getLocation());
callee.init();
callee.setTarget(this.startTarget);
callee.execute();
// Should never reach this point as the target is blocking, unless
the
// server is stopped.
}
/**
* @param theStartTarget the Ant target to call
*/
public void setStartTarget(String theStartTarget) {
this.startTarget = theStartTarget;
}
}
--------%<-----[StartServerHelper.java]-----------
