What I usually do is, in Eclipse preferences, I define an Installed JRE called "JDK X.Y.Z" and include tools.jar as part of it libraries. Then I change the project preferences to use that JRE "JDK X.Y.Z".
InstaSearch is an Eclipse plug-in for doing fast text search in the workspace. The search is performed instantly as-you-type and resulting files are displayed in an Eclipse view. It is a lightweight plug-in based on Apache Lucene search engine. Each file then can be previewed using few most matching and relevant lines. A double-click on the match leads to the matching line in the file. Main Features Instantly shows search results Shows suggestions using auto-completion
Help -> Install New Software
Choose "Helios - http://download.eclipse.org/releases/helios" site
Expand "Web, XML, and Java EE Development"
Check JST Server Adapters (version 3.2.2)
G. Schmidt, и I. Novakovic. Proceedings of the Poster and Demonstration Session at the 7th International Semantic Web Conference (ISWC 2008), Karlsruhe, Germany, (2008)