import org.eclipse.ui.internal.registry.FileEditorMapping; //导入依赖的package包/类
private void updateDefaultEditorMappingIfAbsent() {
	final EditorRegistry registry = (EditorRegistry) WorkbenchPlugin.getDefault().getEditorRegistry();
	for (final IFileEditorMapping editorMapping : registry.getFileEditorMappings()) {
		final IEditorDescriptor defaultEditor = editorMapping.getDefaultEditor();
		if (null == defaultEditor) {

			final String extension = editorMapping.getExtension();
			LOGGER.info("No default editor is associated with files with extension: '." + extension + "'.");
			final IEditorDescriptor defaultTextEditor = registry.findEditor(DEFAULT_TEXT_EDITOR_ID);
			if (null != defaultTextEditor) {
				((FileEditorMapping) editorMapping).setDefaultEditor(defaultTextEditor);
				String editorName = defaultTextEditor.getLabel();
				if (null == editorName) {
					editorName = defaultTextEditor.getId();
				}
				if (null != editorName) {
					LOGGER.info("Associated files with extension " + extension + " with '" + editorName + "'.");
				}
			}
		}
	}
	registry.saveAssociations();
	PrefUtil.savePrefs();
}
 

import org.eclipse.ui.internal.registry.FileEditorMapping; //导入依赖的package包/类
@Override
public void earlyStartup() {
	EditorRegistry editorReg = (EditorRegistry)PlatformUI.getWorkbench().getEditorRegistry();
	EditorDescriptor editor = (EditorDescriptor)editorReg.findEditor("org.eclipse.ui.DefaultTextEditor");
	FileEditorMapping mapping = new FileEditorMapping("inf");
    mapping.addEditor(editor);
    mapping.setDefaultEditor(editor);
    
    IFileEditorMapping[] mappings = editorReg.getFileEditorMappings();
    FileEditorMapping[] newMappings = new FileEditorMapping[mappings.length+1];
    for (int i = 0; i < mappings.length; i++) {
        newMappings[i] = (FileEditorMapping) mappings[i];
    }
    newMappings[mappings.length] = mapping;
    
    Display.getDefault().asyncExec(new Runnable() {
		@Override
		public void run() {
			editorReg.setFileEditorMappings(newMappings);
		}
	});
    
	//reg.setDefaultEditor("inf", "org.eclipse.ui.DefaultTextEditor");
}
 

import org.eclipse.ui.internal.registry.FileEditorMapping; //导入依赖的package包/类
public static void resetDefaultEditor(String extension) {
  EditorRegistry editorRegistry = (EditorRegistry) PlatformUI.getWorkbench().getEditorRegistry();
  IFileEditorMapping[] editorMappings = editorRegistry.getFileEditorMappings();

  // Search the file=>editor mappings for the specified extension
  for (IFileEditorMapping editorMapping : editorMappings) {
    if (extension.equals(editorMapping.getExtension())) {
      FileEditorMapping internalMapping = (FileEditorMapping) editorMapping;
      // Only need to do anything if there's an explicit default set
      if (internalMapping.getDeclaredDefaultEditors().length > 0) {
        // Clear any default editor associations for this extension

        List<IEditorDescriptor> list = new ArrayList<IEditorDescriptor>();
        internalMapping.setDefaultEditors(list);

        // Save the updated editor registry to disk
        editorRegistry.saveAssociations();

        // TODO: remove
        GWTPluginLog.logInfo("Reset default editor for extension: "
            + extension);
      }
      break;
    }
  }
}
 

import org.eclipse.ui.internal.registry.FileEditorMapping; //导入依赖的package包/类
private void setAnATLyzerDefaultEditor() {
	String extension = "atl";
    String editorId = "org.eclipse.m2m.atl.adt.editor.AtlEditor";

    EditorRegistry editorReg = (EditorRegistry)PlatformUI.getWorkbench().getEditorRegistry();
    //EditorDescriptor editor = (EditorDescriptor) editorReg.findEditor(editorId);
    //editor.
    IFileEditorMapping[] mappings = editorReg.getFileEditorMappings();
    for (IFileEditorMapping mapping : mappings) {
    	if ( "atl".equals(mapping.getExtension()) ) {
    	   	IEditorDescriptor[] descriptors = mapping.getEditors();
    	   	IEditorDescriptor anatlyzerEditor = null;
    	   	for (IEditorDescriptor editorDesc : descriptors) {
				if ( "anatlyzer.atl.editor.AtlEditorExt".equals( ((EditorDescriptor) editorDesc).getClassName()) ) {
					anatlyzerEditor = editorDesc;
					break;
				}
			}
    	   	
    	   	if ( anatlyzerEditor != null ) {
    	   		((FileEditorMapping) mapping).setDefaultEditor((EditorDescriptor) anatlyzerEditor);
    	   		break;
    	   	}
    	}
	}
}
 

import org.eclipse.ui.internal.registry.FileEditorMapping; //导入依赖的package包/类
@Override
public void register(IVizService service) {
	if (service != null) {
		String name = service.getName();

		// Put the service in service map so it can be retrieved later
		serviceMap.put(name, service);

		// Register the plot editor as default editor for all file
		// extensions handled by the new viz service
		for (String ext : service.getSupportedExtensions()) {
			EditorRegistry editorReg = (EditorRegistry) PlatformUI
					.getWorkbench().getEditorRegistry();
			EditorDescriptor editor = (EditorDescriptor) editorReg
					.findEditor("org.eclipse.eavp.viz.service.PlotEditor");
			FileEditorMapping mapping = new FileEditorMapping(ext);
			mapping.addEditor(editor);
			mapping.setDefaultEditor(editor);

			IFileEditorMapping[] mappings = editorReg
					.getFileEditorMappings();
			FileEditorMapping[] newMappings = new FileEditorMapping[mappings.length
					+ 1];
			for (int i = 0; i < mappings.length; i++) {
				newMappings[i] = (FileEditorMapping) mappings[i];
			}
			newMappings[mappings.length] = mapping;
			editorReg.setFileEditorMappings(newMappings);
		}

		logger.info("VizServiceFactory message: " + "Viz service \"" + name
				+ "\" registered.");
	}

	return;
}
 

import org.eclipse.ui.internal.registry.FileEditorMapping; //导入依赖的package包/类
public void run()
{
	EditorRegistry registry = (EditorRegistry)
		WorkbenchPlugin.getDefault().getEditorRegistry();
	
	IFileEditorMapping[] mappings = registry.getFileEditorMappings();
	IFileEditorMapping c = null;
	IFileEditorMapping cws = null;
	
	// Search Class file editor mappings
	for (IFileEditorMapping mapping : mappings) 
	{
		if (mapping.getExtension().equals("class")) 
		{
			// ... Helios 3.6, Indigo 3.7, Juno 4.2, Kepler 4.3, ...
			c = mapping;
		}
		else if (mapping.getExtension().equals("class without source")) 
		{
			// Juno 4.2, Kepler 4.3, ...
			cws = mapping;
		}
	}

	if ((c != null) && (cws != null))
	{
		// Search JD editor descriptor on "class" extension
		for (IEditorDescriptor descriptor : c.getEditors())
		{		
			if (descriptor.getId().equals(EDITOR_ID))
			{
				// Remove JD editor on "class" extension
				//((FileEditorMapping)c).removeEditor((EditorDescriptor)descriptor);

				// Set JD as default editor on "class without source" extension
				registry.setDefaultEditor(
					"." + cws.getExtension(), descriptor.getId());
				break;
			}
		}
		
		// Restore the default editor for "class" extension
		IEditorDescriptor defaultClassFileEditor = 
			registry.findEditor(JavaUI.ID_CF_EDITOR);	
		if (defaultClassFileEditor != null)
		{
			registry.setDefaultEditor(
				"." + c.getExtension(), JavaUI.ID_CF_EDITOR);
		}				
		
		registry.setFileEditorMappings((FileEditorMapping[]) mappings);
		registry.saveAssociations();			
	}
}