Use javac fork attribute with IBM JDK

I have a large ant build that I'm working on, that is currently running out of memory. One ways I've read that can help mitigate this problem is to use javac fork="true" to run javac in a separate jvm.

My problem is that I need to compile the project with the IBM JDK (this is not the JDK referenced by JAVA_HOME, and I would prefer it not to be). I tried setting开发者_JAVA百科 the executable attribute of Ant's javac, to the path to IBM's javac but no joy (the project still won't compile). Ant's docs for the executable attribute state:

Complete path to the javac executable to use in case of fork="yes". Defaults to the compiler of the Java version that is currently running Ant. Ignored if fork="no". Since Ant 1.6 this attribute can also be used to specify the path to the executable when using jikes, jvc, gcj or sj.

Does anyone have any ideas?

Thanks -

I have used a single ANT build to compile a set of classes in 1.7 and another set of classes in 1.6 and it works fine.

Both 1.7 and 1.6 are IBM JDK's. JAVA_HOME points to the 1.7 JDK & ANT version is 1.9

Below are the ANT tags used

1.7 compilation using JAVA_HOME

`<javac srcdir="${LOCAL_SOURCE_PATH}/temp" debug="true" deprecation="false" fork="true" memoryInitialSize="1024M" memoryMaximumSize="1500M" verbose="${verbose}">`

1.6 compilation using javac tags executable attribute

`<javac srcdir="${LOCAL_SOURCE_PATH}/branchtmp" fork="true" executable="${JAVA6_HOME}/bin/javac" compiler="javac1.6" debug="true" deprecation="false"memoryInitialSize="1024M" verbose="${verbose}">`

Hope this helps.