I guess that you are trying to replace a standard class which ships with Java 5 with one in a library you have.
This is not permitted under the terms of the license agreement, however AFAIK it wasn't implemented until Java 5
Here's a solution that also works.
- First, Go to the Build Path settings in the project properties.
- Delete the JRE System Library
- Attach it back; Select "Add Library" and choose the JRE System Library. The default ran for me.
This runs because you have multiple classes in different jar files. Deleting and re-attaching the JRE lib will make the right classes be first. If you want a basic solution make sure you omit the jar files with the same classes.
I hold javax.xml.soap.SOAPPart in three different jars: axis-saaj-1.4.jar, saaj-api-1.3.jar, and the rt.jar