struts2_方法拦截器

使用方法拦截器的步骤:

1. 继承MethodFilterInterceptor抽象类，实现自己的方法拦截器类(重写doIntercept()方法)
2. 在struts.xml中声明拦截器
3. 在struts.xml中使用拦截器

MethodInterceptor.java:(自定义方法拦截器)

package com.sunflower.interceptor;

import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.interceptor.MethodFilterInterceptor;

public class MethodInterceptor extends MethodFilterInterceptor {

    protected String doIntercept(ActionInvocation arg0) throws Exception {
        System.out.println("method interceptor before invoke--------");

        String result = arg0.invoke();

        System.out.println("method interceptor after invoke---------");

        return result;
    }

}

struts.xml:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"
    "http://struts.apache.org/dtds/struts-2.3.dtd">

<struts>
    <constant name="struts.devMode" value="true"></constant>

    <package name="struts" extends="struts-default">

        <!-- 声明拦截器 -->
        <interceptors>
            <interceptor name="test"
                class="com.sunflower.interceptor.MyInterceptor">
            </interceptor>
            <interceptor name="domethod"
                class="com.sunflower.interceptor.MethodInterceptor">
            </interceptor>
        </interceptors>

        <action name="token" class="com.sunflower.action.Action">

            <result name="success">/welcome.jsp</result>
            <result name="invalid.token">/alert.jsp</result>

            <!-- 使用拦截器 -->
            <interceptor-ref name="test"></interceptor-ref>
            <interceptor-ref name="token"></interceptor-ref>
            <interceptor-ref name="defaultStack"></interceptor-ref>

        </action>

        <action name="myaction" class="com.sunflower.action.MyAction" method="myExecute">
            <result name="success">/welcome.jsp</result>
            
            <interceptor-ref name="domethod">
                <param name="excludeMethods">myExecute</param>
            </interceptor-ref>
        </action>
    </package>
</struts>    

关键点：

注意：

默认情况下(不指明excludeMethods和不指明includeMethods)会默认的将方法作为includeMethods参数.
使用自定义拦截器后面一定要加上默认拦截器栈(defaultStack)，否则程序部分功能会失效