How to redirect Ant output to a JTextArea

If you need to capture an Ant script output and resend it to an JTextArea (or similar components), you can try a few solutions. For my purposes I solved this task by writing a new logger that extends the DefaultLogger and overwrite the buildFinished, buildStarted and messageLogged methods:

class MyLogger extends DefaultLogger {

        @Override
        public void buildFinished(BuildEvent be) {
            outputTextArea.append("[BUILD FINISHED]\n");
        }

        @Override
        public void buildStarted(BuildEvent be) {
            outputTextArea.append("[BUILD STARTED]\n");
        }

        @Override
        public void messageLogged(BuildEvent be) {
            outputTextArea.append(be.getMessage() + "\n");
        }
    }

Next, MyLogger was set to the current Project:

private boolean runAntScript(String scriptName) {

        File buildFile = new File(scriptName);
        Project project = new Project();
        MyLogger myLogger = new MyLogger();

        project.setUserProperty("ant.file", buildFile.getAbsolutePath());
        myLogger.setErrorPrintStream(System.err);
        myLogger.setOutputPrintStream(System.out);
        myLogger.setMessageOutputLevel(Project.MSG_INFO);

        project.addBuildListener(myLogger);

        try {
            project.fireBuildStarted();
            project.init();
            ProjectHelper helper = ProjectHelper.getProjectHelper();
            project.addReference("ant.projectHelper", helper);
            helper.parse(project, buildFile);
            project.executeTarget(project.getDefaultTarget());
            project.fireBuildFinished(null);
        } catch (Exception e) {
            project.fireBuildFinished(e);            
            return false;
        }

        return true;
    }

Another solution is to implement the org.apache.tools.ant.BuildListener interface. This interface will force you to overwrite more methods but provide more control, as you can see below:

class myBuildListener implements org.apache.tools.ant.BuildListener  {

        public void buildFinished(BuildEvent be) {
             outputTextArea.append("[BUILD FINISHED]\n");
        }

        public void buildStarted(BuildEvent be) {
             outputTextArea.append("[BUILD STARTED]\n");
        }

        public void messageLogged(BuildEvent be) {
            outputTextArea.append(be.getMessage() + "\n");
        }

        public void targetFinished(BuildEvent be) {
            throw new UnsupportedOperationException("Not supported yet.");
        }

        public void targetStarted(BuildEvent be) {
            throw new UnsupportedOperationException("Not supported yet.");
        }

        public void taskFinished(BuildEvent be) {
            throw new UnsupportedOperationException("Not supported yet.");
        }

        public void taskStarted(BuildEvent be) {
            throw new UnsupportedOperationException("Not supported yet.");
        }
      
    }

Finally, a third solution is to send the Ant script output to a pipe:

private boolean runAntScript(String scriptName) {

        PipedOutputStream pipeOut = null;
        PipedInputStream pipeIn = null;
        BufferedReader pipeReader = null;

        try {
            pipeOut = new PipedOutputStream();
            pipeIn = new PipedInputStream(pipeOut);
            pipeReader = new BufferedReader(new InputStreamReader(pipeIn));

            System.setOut(new PrintStream(pipeOut));
            System.setErr(new PrintStream(pipeOut));
        } catch (IOException e) {            
            return false;
        }

        File buildFile = new File(scriptName);
        Project project = new Project();
        DefaultLogger consoleLogger = new DefaultLogger();

        project.setUserProperty("ant.file", buildFile.getAbsolutePath());
        consoleLogger.setErrorPrintStream(System.err);
        consoleLogger.setOutputPrintStream(System.out);
        consoleLogger.setMessageOutputLevel(Project.MSG_VERBOSE);
        project.addBuildListener(new myBuildListener());

        try {
            project.fireBuildStarted();
            project.init();
            ProjectHelper helper = ProjectHelper.getProjectHelper();
            project.addReference("ant.projectHelper", helper);
            helper.parse(project, buildFile);
            project.executeTarget(project.getDefaultTarget());
            project.fireBuildFinished(null);         
        } catch (Exception e) {
            project.fireBuildFinished(e);
            return false;
        }

        return true;
    }

Next, you will need a separate thread to read form pipe and put in the text area. This can be implemented through Java multi-threading capabilities in a few lines of code.


Well, there’s my solutions! Please fill free to bring other new and better ones.

From http://e-blog-java.blogspot.com/2011/04/how-to-redirect-ant-output-to-jtextarea.html