从独立的Java文件中为Eclipse插件获取ICompilationUnit / ITypeRoot

Question

I am hacking an Eclipse Plugin that is working perfectly for Java files in Java projects. I want to make it work for Java files in any kind of project.

This plugin processes each Java file as a ICompilationUnit . However, in my approach I can only get an instance of IFile .

How can I create a ICompilationUnit from this IFile object?

As alternative a ITypeRoot might also work. I've seen this being created directly from the editor using the following:

IJavaElement input= JavaUI.getEditorInputJavaElement(editorInput);
        if (input instanceof ITypeRoot) {
            return (ITypeRoot) input;
        }

This approach works even with non Java projects (java files from generic projects/directories that are opened in the editor), which makes me believe that something similar can be achieved for files directly.

Answer 1

JavaCore.create(IFile) will return an ICompilationUnit if that is appropriate for the file:

IFile file = ...

IJavaElement element = JavaCore.create(file); 

if (element instanceof ICompilationUnit) {
  ICompilationUnit compUnit = (ICompilationUnit)element;

  ...
}

Other objects may be returned, for example IClassFile for a .class file.