I have no idea how to use ,regular expression in eclipse ,I searched Google also, but I cant get any information from that ,anybody please help in this .
If you are asking about the regular expression feature of the Find/Replace dialog, you can find a lot of help in the Javadocs for the java.util.regex package.
If are trying to enter a regular expression in the dialog itself, you can hold down the CTRL key and press the spacebar key. That pops up suggested options and their uses.
The secret of how to be miserable is to constantly expect things are going to happen the way that they are "supposed" to happen.
You can have faith, which carries the understanding that you may be disappointed. Then there's being a willfully-blind idiot, which virtually guarantees it.
And in case you are looking to have a functionality wherein you can test your own regular expressions, I think, default eclipse installation doesn't come with it, you may add 'plugins' to get such special features.