I found that the Java Editor in Eclipse didn't return the resource of some Images after display dispose by using Sleak Tool (it can be downloaded from
http://dev.eclipse.org/viewcvs/index.cgi/%7Echeckout%7E/platform-swt-home/dev.html#tools.) This may lead to memory leaks in JVM Heap dump.
Steps:
1. Download and install the Sleak. ( It's helpful to download performance tool to run Garbage Collector in order to get more precise result )
2. Click the "Snap" before opening an .java file ( If Run "Garbage Collector" in performance menu before this operation, we can assure we are get rid of unused (untouched) objects in java heap)
3. Open and exit .java file. Click "Diff" ( Again, Run GC before this operation )
(Note: Don't click Snap twice, clicking Diff means taking snap for current environment and then compare)
Sometimes, one incremental image occured. Sometimes, more seriously, 11 incremental images still live in memory. Most of them are the Icon Images of Buttons in "Outline" view.