Run Ant target in background without using spawn=true

Question

I would like to start a server in background, go back and execute some other targets, and then stop the server when Ant finishes executing all targets.

I have come up with the following two solutions but they both block Ant from executing the subsequent targets.

Since I want the process to die in the end, I do not want to use spawn="true". Is there any other solution?

<target name="Start_Selenium_Server">
    <java dir="lib" jar="lib/selenium-server-standalone-2.28.0.jar" fork="true">
        <arg line="-singleWindow -userExtensions user-extensions.js"/>
    </java>
</target>   

<target name="Start_Selenium_Server">
    <exec dir="lib" executable="java" newenvironment="true" output="./log/StartSeleniumServer.log">
        <arg line="-jar selenium-server-standalone-2.28.0.jar -singleWindow -userExtensions user-extensions.js" />
    </exec>
</target>   

Answer 1

Wrap the call using the parallel task and the daemons nested element

<target name="Start_Selenium_Server">
    <parallel> 
        <daemons>
            <java dir="lib" jar="lib/selenium-server-standalone-2.28.0.jar" fork="true">
               <arg line="-singleWindow -userExtensions user-extensions.js"/>
            </java>
        </daemons>
 <parallel> 
</target>