Calling Ant From Java

[Nikhil Jain]

Hi,
I need to call ant from java. Currently I am calling ant as a subprocess in my java code for ex
Process p = new Process()'
p.execute("ant.bat xxxx")

I need to call the ant within my java code. Can someone help me out. I tried viewing launcher.jar but I see that the run method in launcher class is private methods. IS THERE ANY OTHER way to call ant within java code.

Thanks

[Nikhil Jain]

I included ant.jar & ant-launcher.jar

I wrote the following code

    
String arr[] = null;
arr = new String[2];
arr[0] = "-buildfile";
arr[1] = "C:\\workspace\\build.xml";
Launcher launcher = new Launcher();
launcher.main(arr);

Is this the correct way of calling ant from java. Secondly I get the following output when I execute the above code.

    
[B]Unable to locate tools.jar. Expected to find it in C:\Program Files\Java\jre1.5.0_06\lib\tools.jar[/B]
Buildfile: C:\workspace\my projects\ANTTASKS\bin\build.xml
 
demo:
    [pvget] Getting: <a href="http://hscommunicate" target="_blank" rel="nofollow">http://hscommunicate</a>
 
BUILD SUCCESSFUL
Total time: 3 seconds

It executed fine but it also gave unable to locate tools.ajr error.
I called the code from eclipse.

Thanks
Shashank

[Nikhil Jain]

again, the problem which I am facing is how do I get errors or kill the code if its taking lot of time eg. connection timout out...

[Tim Holloway]

http://ant.apache.org/manual/running.html#viajava

Somewhere in the Ant docs I think there's something on invoking Ant from within another Java app, but you can also start a new JVM using the information above and the Runtime.exec() facility. Runtime will allow you to capture stdout and stderr.

For more sophisticated operation such as the wat Ant is invoked from IDEs there's also some callback functionality listed in the Ant docs somewhere. I think it was originally under "Ant in anger".

[Nikhil Jain]

Hi,

I currently using runtime.exec() only. The problem with this is that, it acts like an external process & spawns another thread. I wanted to invoke ant as a normal java class. But when I do that, I don't get ant's error & input. Is there any way of doing this.

Thanks
Shashank

[arulk pillai]

The Ant launcher may not process environment variables since java
does not provide access to these. You can try one of the following

1. Just use the java command from the JDK area directly and not rely on
the operating System path to find it.

%JAVA_HOME%\bin\java -jar ant-launcher.jar -buildfile /path/to/build.xml

2. make sure tools.jar in the classpath

java -cp %JAVA_HOME%\lib\tools.jar;ant-launcher.jar
org.apache.tools.ant.launch.Launcher -buildfile /path/to/build.xml

[Tim Holloway]

Originally posted by Shashank Tilwalli:
Hi,

I currently using runtime.exec() only. The problem with this is that, it acts like an external process & spawns another thread. I wanted to invoke ant as a normal java class. But when I do that, I don't get ant's error & input. Is there any way of doing this.

Thanks
Shashank

OK, if you want to run Ant inside the same JVM as the spawning program, as I said, there should be some stuff in the Ant docs on how to do that - I'm just too lazy to track them down. Part of that documentation includes how to jack in callbacks to catch the output from Ant.