If you try to install eclipse using apt-get install eclipse
it will install eclipse with gcj support that is soooo slow.
If you want to install only eclipse without gcj you can use apt-get --no-install-recommends install eclipse
and maybe edit the file /etc/eclipse/java_home
to change the search order of JAVA_HOME
Obliviously you need to have a valid java installed. I suggest sun-java6-jdk since it’s the faster one.