如何在Struts 2中使用DispatcherListener

Struts2中有一个接口DispatcherListener 。 文档说

“用于标记那些想要在init上执行代码并destroy Dispatcher的接口的接口。”

但是如何使用这个界面。 如果我创建一个实现此接口的类,我应该如何配置它到Struts2?

实例化Dispatcher ,它可以在初始化或销毁时向监听器发送通知。 参考和代码示例来自此处 。

简单的用法是通过bean标签通过容器实例化bean,并在init方法中添加它们,并在销毁时将其自身移除,就像ClasspathConfigurationProvider

代码是原始的,只是为了向您展示这个想法

struts.xml

  

MyBean.java

 public class MyBean implements ConfigurationProvider, DispatcherListener { public MyBean() { System.out.println("!!! MyBean !!!"); } @Override public void dispatcherInitialized(Dispatcher du) { System.out.println("!!! dispatcherInitialized !!!"); } @Override public void dispatcherDestroyed(Dispatcher du) { System.out.println("!!! dispatcherDestroyed !!!"); } @Override public void destroy() { System.out.println("!!! destroy !!!"); Dispatcher.removeDispatcherListener(this); } @Override public void init(Configuration configuration) throws ConfigurationException { System.out.println("!!! init !!!"); Dispatcher.addDispatcherListener(this); } @Override public boolean needsReload() { return false; } @Override public void loadPackages() throws ConfigurationException { } @Override public void register(ContainerBuilder builder, LocatableProperties props) throws ConfigurationException { } } 

输出:

 15:27:50 INFO (org.apache.struts2.spring.StrutsSpringObjectFactory:42) - ... initialized Struts-Spring integration successfully !!! MyBean !!! !!! init !!! jul 18, 2013 3:27:51 PM org.apache.catalina.startup.HostConfig deployDirectory !!! dispatcherInitialized !!! [2013-07-18 06:28:11,102] Artifact jspbean:war exploded: Artifact is deployed successfully INFO: A valid shutdown command was received via the shutdown port. Stopping the Server instance. INFO: Stopping service Catalina !!! dispatcherDestroyed !!! 

如果您使用的是Spring,则可以创建监听器的bean,并在构造函数中将其添加到dispatcherListeners列表中。

 public YourDispatcherListener () { Dispatcher.addDispatcherListener(this); } 

另一个解决方案是创建ServletContextListener ,它创建您的调度程序侦听器并将其添加到列表中。