Hi Shawn
The 1.5.0_28 that is shown in your trace above refers to the JRE version of your PI system.
JDK and JRE are different (you can search on the web on what is the difference) and so are the versions.
The highest version of JDK 1.5 released by Sun/Oracle is 22, AFAIK, you won't be able to find a version 28 anywhere.
You should be able to use that version in your NWDS to develop for PI7.11.
Rgds
Eng Swee