A small example of the implementation of the STRUTS2 analog interceptor

1. Interceptor interface

 Public Interface Interceptor {    void  Interceptor (actioninvocation invocation);}

2. Make 3 implementations of the interface

 Public classFirstinterceptorImplementsInterceptor { Public voidInterceptor (Actioninvocation invocation) {System.out.println (1);        Invocation.invoke (); System.out.println (-1); }} Public classSecondinterceptorImplementsinterceptor{ Public voidInterceptor (Actioninvocation invocation) {System.out.println (2);        Invocation.invoke (); System.out.println (-2); }} Public classThirdinterceptorImplementsinterceptor{ Public voidInterceptor (Actioninvocation invocation) {System.out.println (3);        Invocation.invoke (); System.out.println (-3); }}

3. An Action object

 Public class Action {    publicvoid  execute () {        System.out.println ("Execute executed!!! ");    }}

4.ActionInvocation initializes the implementation of 3 interceptors to the list, simulating the interceptor stack

1  Public classactioninvocation {2List<interceptor> interceptors =NewArraylist<interceptor>();3     intindex =-1;4Action A =NewAction ();5     6      Publicactioninvocation () {7          This. Interceptors.add (Newfirstinterceptor ());8          This. Interceptors.add (Newsecondinterceptor ());9          This. Interceptors.add (Newthirdinterceptor ());Ten     } One      Public voidInvoke () { Aindex++; -          -         if(Index >= This. Interceptors.size ()) { the A.execute (); -}Else { -              This. Interceptors.get (Index). Interceptor ( This); -         } +     } -}

5. Running

 Public class Main {    publicstaticvoid  main (string[] args) {        new actioninvocation (). Invoke ();    }}

6. Results

1
2
3
Execute executed!!!
-3
-2
-1

A small example of the implementation of the STRUTS2 analog interceptor