webwork的interceptor来实现ajax功能(buffalo)

已经很久没有来bolg了，现在有空，就把最近写的一个webwork的拦截器放上来给大家参考，如果有bug或有更好的实现办法，可以email给我。

下面是interceptor的实现代码：

 1  package  interceptor;
 2 
 3  import  java.io.IOException;
 4 
 5  import  org.apache.log4j.Logger;
 6 
 7  import  com.caucho.burlap.io.BurlapInput;
 8  import  com.caucho.burlap.io.BurlapOutput;
 9  import  com.caucho.burlap.server.BurlapSkeleton;
10  import  com.opensymphony.webwork.ServletActionContext;
11  import  com.opensymphony.xwork.ActionInvocation;
12  import  com.opensymphony.xwork.interceptor.Interceptor;
13 
14  public   class  BurlapInterceptor  implements  Interceptor {
15       private   static  Logger logger  =  Logger.getLogger(BurlapInterceptor. class );
16       public   void  destroy() {
17           //  TODO Auto-generated method stub
18 
19      }
20 
21       public   void  init() {
22           //  TODO Auto-generated method stub
23 
24      }
25 
26       public  String intercept(ActionInvocation invocation)  throws  Exception {
27          BurlapInput in  =   new  BurlapInput(ServletActionContext.getRequest()
28                  .getInputStream());
29 
30          BurlapOutput out  =   new  BurlapOutput(ServletActionContext.getResponse().getOutputStream()) {
31               public   void  startReply()  throws  IOException {
32                  print( " <?xml version=\ " 1.0 \ "  encoding=\ " utf - 8 \ " ?><burlap:reply xmlns:burlap=\ " http: // www.buffalo.net/burlap/\">");
33              }
34          };
35 
36          BurlapSkeleton _skeleton  =   new  BurlapSkeleton(invocation.getAction());
37 
38           try  {
39              _skeleton.invoke(in, out);
40          }
41           catch  (Throwable e) {
42              logger.error( " Could not invoke burlap " , e);
43          }
44           return   null ;
45      }
46 
47  }
48 

然后在xwork.xml中定义：

1           < interceptors >
2                 < interceptor  name ="burlap"  class ="interceptor.BurlapInterceptor" />         
3            </ interceptors >
4 

最好就可以使用这个拦截器定义自己的bean了，例如：

1      < action  name ="classtree"  class ="classTreeAction"  method ="getClassList" >
2          < interceptor-ref  name ="burlap"   />
3      </ action >

在页面上就可以用如下javascript代码去调用这个action：
   var bfl = new Buffalo("classtree.page");
   bfl.remoteCall("getClassList",[acadyear,semester],function(reply){...});

如果你不了解buffalo，可以去他的网站看看： http://www.amowa.net/buffalo/