In my previous blog post, I provided some sample code showing how to execute ant targets programatically from Java. This code showed how to execute the default ant target.

Enumerating the targets is a similarly easy process. The code below shows how to iterate through all the ant targets within an ant build file.

Project p = new Project(); 
// Setup Project p 
Hashtable table = p.getTargets(); 
Set set = table.keySet(); 
Iterator iter = set.iterator(); 
while (iter.hasNext()) { 
    System.out.println("Target:"+(String)iter.next()); 
}

Executing ant tasks programatically via Java is fairly straightforward as shown in the following code sample. To compile and run the following code, ensure you have ant.jar, xercesImpl.jar, xml-apis.jar and ant-launcher.jar (all from the ant lib directory) on your claspath.

/* 
 * AntRunner.java 
 */
  
import java.io.File; 
import org.apache.tools.ant.DefaultLogger; 
import org.apache.tools.ant.Project; 
import org.apache.tools.ant.ProjectHelper; 
import org.apache.tools.ant.taskdefs.Ant; 
  
public class AntRunner { 
  
    public AntRunner() { 
    } 
  
    public static void main(String args[]) throws Exception { 
        File buildFile = new File("/path/to/build.xml"); 
        Project p = new Project(); 
        p.setUserProperty("ant.file", buildFile.getAbsolutePath()); 
        p.init(); 
        ProjectHelper helper = ProjectHelper.getProjectHelper(); 
        p.addReference("ant.projectHelper", helper); 
        helper.parse(p, buildFile); 
        DefaultLogger consoleLogger = new DefaultLogger(); 
        consoleLogger.setErrorPrintStream(System.err); 
        consoleLogger.setOutputPrintStream(System.out); 
        consoleLogger.setMessageOutputLevel(Project.MSG_INFO); 
        p.addBuildListener(consoleLogger); 
        p.executeTarget(p.getDefaultTarget()); 
    } 
}