Memory Leak Analyzer (Got java.lang.RuntimeException: java.lang.OutOfMemoryError: Java heap space)

One fine morning my client was asked me to develop an a small Framework as per his needs. And I started writing code in Java which drives lot of excel files , xmls etc. Due to emergency I delivered  code to accomplish the immediate needs and knowing that it may have some memory leaks which I need to fix and which is my next immediate high priority one.

So I used MAT to find and analyze the code. And found it was really a cool plug-in.
1. How to install MAT plugin
Install plugin from - http://download.eclipse.org/mat/1.2/update-site/
2. MAT generates .hprof file , how to get it.
In Run-Configuration , under Argument tab in VM argument section added
    -XX:+HeapDumpOnOutOfMemoryError
3. If .hprof file is too big?
Add -vmargs -XX:PermSize=256m -XX:MaxPermSize=256m -Xms256m -Xmx1024m into eclipse.ini
4.How to open .hprof in Eclipse.
 Open MAT perspective , and File->Open Head Dump and Open .hprof generated in the project.
5.Analysis....