IResourceChangeListener being called twice with one change

问题

I'm using the IResourceChangeListener to listen for workspace/project changes. It's implemented as proposed by the Eclipse example:

IWorkspace workspace = ResourcesPlugin.getWorkspace();
IResourceChangeListener resourceChangeListener = new IResourceChangeListener() {
    public void resourceChanged(IResourceChangeEvent event) {
        System.out.println("Something changed!");
    }
};
workspace.addResourceChangeListener(resourceChangeListener, IResourceChangeEvent.POST_BUILD);

// some time later on ...
workspace.removeResourceChangeListener(resourceChangeListener);

I implemented this code in a relatively new plugin project, but whenever changes are made in the workspace "Something changed!" is thrown twice?

If helpful: The class implements org.eclipse.ui.IStartup. IResourceChangeListener and resourceChanged() are created and inside of earlyStartup().

来源：https://stackoverflow.com/questions/23875766/iresourcechangelistener-being-called-twice-with-one-change