扩展点-org.eclipse.ui.IStartup-优快云博客

本文详细解析了Eclipse中IStartup扩展点的工作原理及应用技巧，包括其执行顺序、如何正确配置和使用，以及带来的优势。通过具体示例展示了如何利用此特性进行插件的早期启动。

此文对帮助文档中IStartup的内容做注解和补充,详情请见Eclipse帮助文档.

*执行顺序

---start()-->earlyStartup()

Plugin.startup(),Plugin.start(BundleContext context),IStartup.earlyStartup().

从3.0开始start()取代startup(),startup()被废弃

---Workbench.runUI(){display.readAndDispatch()->开始激活bundle,startPlugins()->加载org.eclipse.ui.IStartup}

*如何使用这个特性?

---帮助文档如是描述,"Plugins that provide an extension to this extension point are listed in the workbench preferences and the user may disable any plugin from early startup"

举例,

在earlyStartup()中对插件的操作if(Platform.getBundle("cn.com.agree.abop.ide.editor.fd").getState();==Bundle.STARTING){
    try {
        Platform.getBundle("cn.com.agree.abop.ide.editor.fd").uninstall();
    } catch (BundleException e) {
        e.printStackTrace();
    }
}

*注意class - a fully qualified name of the class that implements org.eclipse.ui.IStartup. If not specified, the plug-in class is used. Do not specify the plug-in class as an explicit value, or it will be instantiated twice (once by regular plug-in activation, and once by this mechanism).

若不看源码或尝试执行,这里的注释可能会导致歧义.以下根据实践说明,

---"If not specified, the plug-in class is used"?

其实就是扩展点不起作用,即使Plugin实现IStartup,Plugin也不会被执行.

---"Do not specify the plug-in class as an explicit value"?

若Plugin被定义在IStartup扩展点中,这将意味着产生两个Plugin类实例,所以不推荐.

*使用IStartup的好处

---"the method earlyStartup() will be called from a separate thread"

这个扩展点的意义在于在激活bundle之外,以一个高的优先级完成一些预操作.

转载于:https://www.cnblogs.com/bronte/articles/1814104.html