The Archive Builder Eclipse plug-in provides a wizard to specify the building process of Java archives (jar, war, ear, ...). Then, archives can be manipulated directly through a context menu in the Project Explorer view.
If you've spent any time doing Java programming with Eclipse it must have occurred to you that support for viewing and editing Jar files is a little limited. Having used Eclipse for over eighteen months, and since I hadn't yet built an Eclipse plugin, I decided to dive right in and build a viewer/editor that would let me stop using File Explorer or WinZip(1) for manipulating the Jar files in my projects. Hopefully forever.
Five days later here it is: JarPlug, the Java ARchive PLUGin for Eclipse (sorry... :). And what days: going up the learning curve of Eclipse plugin internals and trying to figure out a workflow paradigm for editing Jar files that made sense inside the Eclipse IDE. More on that later.