fyi: JDK :- Java Development Kit. Sunmicro is the official source/owner of Java
and they have everything you need.
Eclipse is a development workbench; it wraps the compiler and debugger with a
gui interface for writing, compiling, maintaining, and debugging Java programs.
You will need, sooner or later, CVS; Concurrent Versioning System to control
the updates to your sources - look for OpenSources tools whenever possible.