实际上就是对eclipse actionSets扩展点的应用

<extension point="org.eclipse.ui.actionSets">
<actionSet
        id="my.actionSet"
        label="Sample Action Set"
        visible="true">
        <menu
                  id="sampleMenu"
                  label="Sample &amp;Menu">
                  <separator
                           name="sampleGroup">
                  </separator>
       </menu>
       <action
                 class="My.SampleAction"
                 icon="icons/sample.gif"
                 id="My.SampleActionID"
                 label="&amp;Sample Action"
                 menubarPath="sampleMenu/sampleGroup"
                 toolbarPath="sampleGroup"
                 tooltip="Hello, Eclipse world">
        </action>
</actionSet>
</extension>

只需要实现My.SampleAction类就好了，这个类必须实现IWorkbenchWindowActionDelegate或者IWorkbenchWindowPulldownDelegate接口。具体应用参考eclipse help中关于org.eclipse.ui.actionSets扩展点的说明。