Eclipse 3.5.1 Compiler Error :The type OutputFormat is not accessible due to restriction on required library ../rt.jar

Question

This error is weird and i cannot make much sense of it. I've installed EclipseRCP 3.5.1, Java SE 1.6 update 16 and switched to SWT 3.5. I've created a new project, set up the dependencies and tried to compile. When trying to import, use the following:

import com.sun.org.apache.xml.internal.serialize.OutputFormat;
import com.sun.org.apache.xml.internal.serialize.XMLSerializer;

i get the error :

Access restriction: The type XMLSerializer is not accessible due to restriction on required library C:\Program Files\Java\jre6\lib\rt.jar.

I've already google it, read some responses here..and the problem is still there. The funny thing is that if i use the previous EclipseRCP (Version: 3.4.2), this problem never occurs. The 3.4.2 version uses the same JRE version, and i've just tested the SWT version. Works fine. I guess the problem relies in some plugin of the new IDE. Any ideas?

P.S. I have found this article. But i don't like or want to change the code if i don't have to. What is the source of the problem first, and the solution will follow..

Answer 1

The default configuration of the Eclipse compiler is too restrictive. You can loosen it up by opening the preferences for Java -> Compiler -> Errors/Warnings and under "Deprecated and restricted API" change the setting of "Forbidden reference (access rules)" from error to warning or ignore.

A question however is if you really want to use the classes in the com.sun.-package, since you are not guaranteed that these will be available in a VM from a different vendor or a newer VM from Sun.