Eclipse Hangs or Freezes on Startup

Try this:-

1. cd .metadata/.plugins
2. mv org.eclipse.core.resources org.eclipse.core.resources.bak
3. Start eclipse. (It should show an error message or an empty workspace because no project is found.)
4. Close all open editors tabs.
5. Exit eclipse.
6. rm -rf org.eclipse.core.resources (Delete the newly created directory.)
7. mv org.eclipse.core.resources.bak/ org.eclipse.core.resources (Restore the original directory.)
8. Start eclipse and start working

 (Thanks to Olaf)