Struts2 custom interceptor Development

Struts2 custom interceptor Development
Introduction

In the previous article has talked about the basic concepts of interceptor (http://blog.csdn.net/xlgen157387/article/details/45951163), below we implement a custom interceptor together.

Interceptor Interface

public interface Interceptor extends Serializable {    /**     * Called to let an interceptor clean up any resources it has allocated.     */    void destroy();    /**     * Called after an interceptor is created, but before any requests are processed using     * {@link #intercept(com.opensymphony.xwork2.ActionInvocation) intercept} , giving     * the Interceptor a chance to initialize any needed resources.     */    void init();    /**     * Allows the Interceptor to do some processing on the request before and/or after the rest of the processing of the     * request by the {@link ActionInvocation} or to short-circuit the processing and just return a String return code.     *     * @param invocation the action invocation     * @return the return code, either returned from {@link ActionInvocation#invoke()}, or from the interceptor itself.     * @throws Exception any system-level error, as defined in {@link com.opensymphony.xwork2.Action#execute()}.     */    String intercept(ActionInvocation invocation) throws Exception;}

It can be seen that only three methods need to be implemented in the interface.

Implement the Interceptor Interface

Public class MyInterceptor implements Interceptor {public void destroy () {System. out. println ("destroy () ----");} public void init () {System. out. println ("init () ----");} public String intercept (ActionInvocation invocation) throws Exception {System. out. println ("before the Action is executed"); String result = invocation. invoke (); System. out. println ("after Result execution"); return result ;}}

We need to configure in the struts. xml file:

          
               
            
    
           
   test            
   
    /welcome.jsp
               
               
            
    
       
  

First declare a custom Interceptor:

Then reference in action:

The execution results can be imagined:

Before the Action is executed, account = test, password = test, submitFlag = login after the Result is executed