I’ll introduce the places where Java + Tomcat configurations need to be changed when switching Eclipse projects.

・[Window] → [Preferences] 　　・[Java] → [Installed JREs] → (Select the appropriate JRE)

　　・[Tomcat] 　　　　・Set [Tomcat Version] to the appropriate one 　　　　・Specify the home in [Tomcat Home] 　　　　(Example) C:Usersyour_usernameDocumentsdevelopmentpleiades-e3.7-ultimate-jretomcat6.0 etc. 　　　　・[JVM Settings] → Set [JRE] to the appropriate one

・Right-click on Project → [Properties] 　　・[Java Compiler] 　　　　・Check [Enable project specific settings]

That’s all from the Gemba.