I use Forte for java  Community Edition, which is based on NetBeans.
I believe that Forte is the predecessor of SUN ONE Studio.

In Forte you can change the "javac" to another "javac" in the Project
properties. for example, if I have a project compiled in JDK 1.4, I
can change the java compiler to the JDK 1.1.8 compiler by setting the
javac options to "C:\jdk1.1.8\bin\javac" (or where ever your JDK
1.1.8 compiler is located). Then when I build my project, it will use
the JDK 1.1.8 compiler instead of the JDK 1.4 compiler.

SUN ONE Studio community edition is free (I think) for downloading.

If you are evaluating Java IDE, you might want to consider Metrowerks
CodeWarrior. CodeWarrior for Windows makes it even easier to switch
java compiler versions.