These are a couple of really useful Eclipse tools for Java development.
JAutodoc – Eclipse Plugin
JAutodoc is an Eclipse Plugin for automatically adding Javadoc and file headers to your source code. It optionally generates initial comments from element name by using Velocity templates for Javadoc and file headers.
EclEmma – Java Code Coverage for Eclipse
EclEmma is a free Java code coverage tool for Eclipse, available under the Eclipse Public License. EclEmma adds a so called launch mode to the Eclipse workbench. It is called Coverage mode and works exactly like the existing Run and Debug modes.