import org.eclipse.compare.IEditableContent; //导入依赖的package包/类
@Override
protected IStructureComparator createStructureComparator(Object input,
		IDocument document, ISharedDocumentAdapter sharedDocumentAdapter,
		IProgressMonitor monitor) throws CoreException {

	final boolean isEditable;
	if (input instanceof IEditableContent)
		isEditable= ((IEditableContent) input).isEditable();
	else
		isEditable= false;

	DocumentRangeNode root= new StructureRootNode(document, input, this, sharedDocumentAdapter) {
		@Override
		public boolean isEditable() {
			return isEditable;
		}
	};

	try {
		monitor = beginWork(monitor);
		parsePropertyFile(root, document, monitor);
	} finally {
		monitor.done();
	}

	return root;
}
 

import org.eclipse.compare.IEditableContent; //导入依赖的package包/类
private IStructureComparator createStructureComparator(final Object input, char[] buffer, IDocument doc, ISharedDocumentAdapter adapter, IProgressMonitor monitor) {
	String contents;
	Map<String, String> compilerOptions= null;

	if (input instanceof IResourceProvider) {
		IResource resource= ((IResourceProvider) input).getResource();
		if (resource != null) {
			IJavaElement element= JavaCore.create(resource);
			if (element != null) {
				IJavaProject javaProject= element.getJavaProject();
				if (javaProject != null)
					compilerOptions= javaProject.getOptions(true);
			}
		}
	}
	if (compilerOptions == null)
		compilerOptions= fDefaultCompilerOptions;

	if (doc != null) {
		boolean isEditable= false;
		if (input instanceof IEditableContent)
			isEditable= ((IEditableContent) input).isEditable();

		// we hook into the root node to intercept all node changes
		JavaNode root= new RootJavaNode(doc, isEditable, input, adapter);

		if (buffer == null) {
			contents= doc.get();
			int n= contents.length();
			buffer= new char[n];
			contents.getChars(0, n, buffer, 0);
		}

		ASTParser parser= ASTParser.newParser(ASTProvider.SHARED_AST_LEVEL);
		if (compilerOptions != null)
			parser.setCompilerOptions(compilerOptions);
		parser.setSource(buffer);
		parser.setFocalPosition(0);
		CompilationUnit cu= (CompilationUnit) parser.createAST(monitor);
		cu.accept(new JavaParseTreeBuilder(root, buffer, true));

		return root;
	}
	return null;
}