Completely remove Eclipse from Ubuntu and its dependencies.

Open a terminal (Ctlr+alt+T) and type the following lines :

     sudo apt-get autoremove eclipse
     rm -r ~/.eclipse/

This will uninstall the dependencies too that were installed along with eclipse.

Install Eclipse JDT on top of CDT.

  All versions of eclipse have a standard base, then a specific set of plugins, depending on the version you are using.

  All you have to do is go to the Help > Install New Software menu, select the eclipse update site

(e.g. for the last one released at the moment"Kepler - http://download.eclipse.org/releases/kepler") , and under the Programming Languages section, select Eclipse Java Development Tools(Or you can type it on the search bar).

  If you don't see the Java Developement Tools in the list, click on the "already installed" link on the install page--you may already have the Java tools installed!

  That's all :-)