Setting JDK in Eclipse

Question

I have two JDKs, for Java 6 and 7.

I want to build my project using both. Initially we only built against 1.6. I see in my project setting I can select 1.5, 1.6 1.7

Answer 1

You manage the list of available compilers in the Window -> Preferences -> Java -> Installed JRE's tab.

In the project build path configuration dialog, under the libraries tab, you can delete the entry for JRE System Library, click on Add Library and choose the installed JRE to compile with. Some compilers can be configured to compile at a back-level compiler version. I think that's why you're seeing the addition version options.