Out of memory on command line build.

I'm moving a large project from Xcode to Eclipse/WOLips.
Within the IDE, i can compile and build fine.
I am having difficulty compiling through the command line though.

Entering:
ant -lib /Developer/Applications/eclipse/plugins/ 
org.objectstyle.wolips.woproject.ant_3.3.5047/lib/woproject.jar compile

Gives me the following errors:
[wocompile] The system is out of resources.
[wocompile] Consult the following stack trace for details.
[wocompile] java.lang.OutOfMemoryError: Java heap space
[wocompile]     at com.sun.tools.javac.parser.Scanner.stringVal 
(Scanner.java:1165)
etc ....

This project has a lot of source code.

In the xcode days, we also ran into a similar memory error when  
compiling.
This was solved by adding -J-mx256m to the JAVA_COMPILER_FLAGS  
setting in the Application target.

Is there a way to increase the memory used by javac within the  
command line?
Why would it compile within the IDE, but run out of memory in the  
command line?