Handle the error Java heap space and PermGen space

In Myeclipse :----
Go to preference server tomcat jdk and paste the following code

-Xms512m -Xmx1024m
XX:PermSize=128m -XX:MaxPermSize=512m
 External Tomcat :----

Go to tomcat configure/java

maximum memory pool=1024

and in java option

-XX:PermSize=128m
-XX:MaxPermSize=512m

Otherwise Go to Catalina.sh and paste the following code

JAVA_OPTS="-Djava.awt.headless=true -Dfile.encoding=UTF-8 -server -Xms1536m
-Xmx1536m -XX:NewSize=512m -XX:MaxNewSize=1024m -XX:PermSize=512m
-XX:MaxPermSize=1024m -XX:+DisableExplicitGC"