While building with ant, I am getting the following error:
java.io.IOException: Cannot run program \"D:\\Tools\\Java\\jdk1.6.0_12\\jre\\bin\\java.exe\
I faced the same problem when launching my GWT application in IBM RAD.
I tried removing duplicate jars, but it didn't solved the issue.
I have changed JRE in the project build path to point to the one which is installed in my machine (C://Program Files->java->...). Earlier it was pointing to the JRE in IBM folder(C://Program Files->IBM->SDP->JDK....)
It worked for me.