Bug 82231 [build path] Hard to find type restriction compiler problem preferences
I20050104-1600 There compiler preference page contains a Warning/Error node with many sub-entries . I tried to find where I could change the 'warning' for the access of internal types to 'error'. No luck until I realized that the Build node also contains Warning/Error settings.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/wizards/buildpaths/BuildPathsBlock.java
IFolder folder= fWorkspaceRoot.getFolder(folderOutput);
					CoreUtility.createFolder(folder, true, true, null);
				}
			}
			
			classpath[i]= entry.getClasspathEntry();
		}	
		
		if (monitor.isCanceled()) {
			throw new OperationCanceledException();
		}
		monitor.worked(1);
				
		fCurrJProject.setRawClasspath(classpath, outputLocation, new SubProgressMonitor(monitor, 7));
		initializeTimeStamps();
	}
	
	public static boolean hasClassfiles(IResource resource) throws CoreException {
		if (resource.isDerived()) { 
			return true;
		}		
		if (resource instanceof IContainer) {
			IResource[] members= ((IContainer) resource).members();
			for (int i= 0; i < members.length; i++) {
				if (hasClassfiles(members[i])) {
					return true;
				}
			}
		}
		return false;