The use of Code search engines are very much increased now. These can help all programmers by quickly filtering billions of lines of source code, all from the default and familiar search interface, to reveal reusable code-snippets. Here you can see eleven links of code search engines/sites.
1. Google Codesearch
2. Koders
3. Krugle
4. Codase
5. Oreilly
6. Quickref
7. DevX
8. Codearchive
9. Ucodit
10. Ruby-lang
And here you can search Open Source Java APIs… Jsourcery
Technorati tags: Code Search Engines
Orange Slate 
Oh yea its a great one friend.
Thanks for ur help
Lijin
Interesting list, but I think you’ve missed one of the best engines: http://merobase.com