How to add external tags file into CEDET in Emacs

Question

I tried to use CEDET to get auto completion in Emacs and that works fine for C/C++. But I cannot find anything about how to use CEDET with Java without the help of JDEE, which is thought out of date and not compatible to CEDET 1.1. I got a tags file using utility found here but I don't know how to integrate that into CEDET system. According to CEDET's website, that's possible. But they don't explain how to do it. Is there someone willing to answer this question?

Here is some sample of the tags file generated by that utility:

java.applet.Applet$AccessibleApplet
    protected java.applet.Applet$AccessibleApplet(java.applet.Applet)
    public java.applet.Applet$AccessibleApplet.getAccessibleRole() returns javax.accessibility.AccessibleRole
    public java.applet.Applet$AccessibleApplet.getAccessibleStateSet() returns javax.accessibility.AccessibleStateSet

Answer 1

It is possible to have CEDET pull in tags from a .jar file. It works by using javap to extract the tags in text form, and then it parses that data.

It isn't very easy to set up since in CEDET, the concept of where to find your library files is part of EDE, the project management system, not the parser and smart completion system. The only Java based project supported in CEDET 1.1 is Android.

The basics is to first enable the javap database by loading it with (require 'semanticdb-javap) in CEDET 1.1, or (require 'semantic/db-javap) in the bzr version of CEDET.

Once you've done that, you can configure it via the cedet-java-classpath-extension. I'm a little fuzzy on the details of what happens next, but folks have reported success on the mailing list.

If you use CEDET from the bzr repository, there is the ede-java-root project, which is similar to the ede-cpp-root project. That project type lets you configure what your library path is. The doc for that is in the ede/java-root.el file with the project type, and shows you the basics of how to use it.