在Struts 2中自定义拦截器的使用

struts2系统自带了很多拦截器，有时需要我们自己定义，一般有两种方式： 

一、实现Interceptor接口

public interface Interceptor extends Serializable{  
     public void init();  
     public void destroy();  
     public String intercept(ActionInvocation invocation)();  
}  

实现上述方法 

二、继承AbstractInterceptor类，重写intercept()方法即可 
  此方法更可行，其实AbstractInterceptor类也就是实现了Interceptor接口 
查看源码打印?

 invocation.invoke();表示该方法执行完后执行Action的execute()方法或者执行下一个拦截器    

 invocation.getAction(); 可以将该法强制转换为Action的类类型 

三、方法拦截器:继承MethodFilterInterceptor类,重写doIntercept()方法


MethodFilerInterceptor实现方法过滤中用到的两个参数

	execludeMethods：该参数指定拦截器拒绝拦截的方法列表，多个方法用“，”隔开，指定了这个参数，

拦截器不会拦截指定列表中的方法，就是所谓的黑名单 
	includeMethods：该参数指定拦截器需要拦截的方法列表，如果指定了参数，则指定的Action在执行前会被拦截，

即白名单。 

定义好自定义拦截器后，就要使用自定义拦截器，在struts.xml文档中

一、包内定义拦截器 
查看源码打印?
 <package....>    

      <interceptors>    
		<!-- 自定义拦截器 start -->
           	<interceptor name="myinterceptor01" class="....01"/> 

		<interceptor name="myinterceptor02" class="....02"/>   
		<!-- 自定义拦截器 end -->

		<!-- 拦截器栈 start -->  
            	<interceptor-stack name="sysModuleStack">  
                	<interceptor-ref name="authority" />  
                	<interceptor-ref name="defaultStack" />  
            	</interceptor-stack> 
            	<interceptor-stack name="toOnLineExamStack">  
                	<interceptor-ref name="toOnLineExamInterceptor" />  
                	<interceptor-ref name="sysModuleStack" />  
            	</interceptor-stack>       

		<!-- 拦截器栈 end -->        

      </interceptors>    

 </package> 
二、action内使用拦截器 
查看源码打印?
<action .....>    
	<result.....></result>    
	<!-- 自定义拦截器使用 start -->

      	<interceptor-ref name="defaultStack" />
      	<interceptor-ref name="myinterceptor01" />
</action> 
主要:可以看出使用了自定义拦截器的action要配置默认拦截器的引用，因为默认拦截器包含了参数的读取、session的管理等功能一下是例子:

myIntersetor01.java

public class MyMethodInterceptor extends MethodFilterInterceptor{  
    protected String doIntercept(ActionInvocation invocation) throws Exception {  
        // TODO Auto-generated method stub  
        System.out.println("进入MyMethodInterceptor方法拦截器!!!!!!!!!!!!!");  
        Map session = invocation.getInvocationContext().getSession();  
        String name = (String) session.get("uname");  
        if (name != null) {  
            return invocation.invoke();  
        }  
        return "input";  
    }  
}  

myIntersetor02.java

package com.eems.exam.intercepter;

import java.util.Map;

import com.bean.Examinee;
import com.eems.exam.testmanage.OnlineExam.action.OnlineExaminneAction;
import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.interceptor.AbstractInterceptor;

public class ToOnLineExamInterceptor extends AbstractInterceptor {
	@Override
	public String intercept(ActionInvocation invocation) throws Exception {
		ActionContext ctx=invocation.getInvocationContext();
		Map session=ctx.getSession();
		Examinee exam = (Examinee) session.get("examinee");
		if(exam == null){
			ctx.put("tip","您还没有登录，请登陆系统");
	        return "HOMELOGIN";
        }
		OnlineExaminneAction action = (OnlineExaminneAction)invocation.getAction();
		String testStuate = action.checkTestStuate(exam);
		if("0".equals(testStuate)){
			ctx.put("tip","您已考试通过，请勿重复考试。");
	        return "examinneRule";
		}
        return invocation.invoke();
	}

}

strtus.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
    "http://struts.apache.org/dtds/struts-2.0.dtd">

<struts>

<!-- 权限控制 -->
 <package name="authority" extends="struts-default">  
       
       <!-- 定义一个拦截器 -->  
        <interceptors>  
            <interceptor name="authority"  
                class="com.eems.exam.intercepter.AuthorityInterceptor">  
            </interceptor>
            <interceptor name="toOnLineExamInterceptor"  
                class="com.eems.exam.intercepter.ToOnLineExamInterceptor">  
            </interceptor>  
             
            <!-- 拦截器栈 -->  
            <interceptor-stack name="sysModuleStack">  
                <interceptor-ref name="authority" />  
                <interceptor-ref name="defaultStack" />  
            </interceptor-stack>
            
            <interceptor-stack name="toOnLineExamStack">  
                <interceptor-ref name="toOnLineExamInterceptor" />  
                <interceptor-ref name="sysModuleStack" />  
            </interceptor-stack>    
        </interceptors>

	<!-- 考生信息 -->
  	<action name="stuInfo" class="StuInfoAction"
   		method="toStuInfo">
   		<result name="success">/webapp/myregister/stuInfo.jsp</result>
   		<!-- 使用此拦截器 -->  
        	<interceptor-ref name="sysModuleStack" />  
  	</action>

	<!-- 初始考试界面 -->
      <action name="toOnlineExaminne" class="OnlineExam" method="toMockExaminne">
         <result name="onlineExameView">/onlineexame/onlineexame.jsp</result>  <!--初始考试界面  -->
         <result name="examinneRule">/onlineexame/result/pass.jsp</result>
             <!-- 使用此拦截器 -->  
            <interceptor-ref name="toOnLineExamStack" />  
        </action> 
       <!-- 上一页或下一页考试界面 -->
        <action name="toNextOnlineExaminne" class="OnlineExam" method="toNextMockExaminne">
         <result name="nextOlineExameView">/onlineexame/onlineexame.jsp</result> 
            <result name="examinneRule">/onlineexame/result/pass.jsp</result>
             <!-- 使用此拦截器 -->  
            <interceptor-ref name="toOnLineExamStack" />   
        </action>
        <!-- 得分界面 -->
        <action name="toOverOlineExame" class="OnlineExam" method="getOverExam">
         <result name="overOnlineExaminneView">/onlineexame/result/onlineresult.jsp</result>
             <result name="examinneRule">/onlineexame/result/pass.jsp</result>
             <!-- 使用此拦截器 -->  
            <interceptor-ref name="toOnLineExamStack" />  
        </action>

  </package>   
   

    
</struts>