I have the eclipse CDT installed, and I would like to install Java development functionality (JDT) on top of my CDT installation. I've been Googling from an hour but I can't figure out how to do this.
What plugin do I need to install? What update site do I need to use?
All versions of Eclipse have a standard base, then a specific set of plugins, depending on the version. All you have to do is go to the Help > Install New Software menu, select the Eclipse update site (e.g. "Galileo - http://download.eclipse.org/releases/galileo"), and under the Programming Languages section, select Eclipse Java Development Tools.
If you don't see the Java Development Tools in the list, click on the "already installed" link on the install page--you may already have the Java tools installed.
Remember to write http:// before the download.eclipse..... if you don't put that it won't work
来源：https://stackoverflow.com/questions/1853450/install-eclipse-jdt-on-top-of-cdt