Increase Weblogic memory in Integrated Weblogic server of Jdeveloper

Go to JDEV_HOME\system12.1.2.0.40.66.68\DefaultDomain\bin and open setDomainEnv.cmd  or setDomainEnv.sh based on whether it is a windows or linux machine.

Scroll down until you see WLS_MEM_ARGS, below that enter

In the case of Windows:
set USER_MEM_ARGS = -Xms64m  -Xmx2048m  -XX:MaxPermSize=1024m

In the case of Linux:
USER_MEM_ARGS="-Xms64m  -Xmx2048m  -XX:MaxPermSize=1024m"
export USER_MEM_ARGS