java build path problems [duplicate]

Answer 1

Here's a good discussion on this:

• How to use JDK 1.6 in 1.5 compliance mode

Basically you should

1. Download and install the 1.5 JDK. (download link)
2. In Eclipse, Go to Window → Preferences → Java → Installed JREs.
3. Add the 1.5 JDK to the list.
4. Select 1.5 as Compiler Compliance Level.