Struts2学习-拦截器

1.新建项目user4,建立好和user3一样的目录，与之相比只是添加几个类，主要是struts.xml和action类的改变，其结果没有太大的变化

 struts,xml

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE struts PUBLIC
        "-//Apache Software Foundation//DTD Struts Configuration 2.5//EN"
        "http://struts.apache.org/dtds/struts-2.5.dtd">

<struts>
    <package name="myPack" extends="struts-default" namespace="/">
        <!--定义一个拦截器-->
        <interceptors>
            <interceptor name="loginInterceptor" class="com.nf.action.LoginInterceptor"></interceptor>
        </interceptors>

        <global-results>
            <result name="login" type="redirectAction">userAction_loginView</result>
        </global-results>


        <action name="userAction_*" class="com.nf.action.UserAction" method="{1}">
            <result name="loginViewSuccess">/WEB-INF/jsp/loginView.jsp</result>
            <result name="success">/WEB-INF/jsp/index.jsp</result>
            <result name="error">/WEB-INF/jsp/error.jsp</result>
            <!--使用通配符后，新版本需要加上allowed-methods-->
            <allowed-methods>login,loginView</allowed-methods>
        </action>

        <action name="testAction" class="com.nf.action.TestAction">
            <!-- name="success"是result的默认值-->
            <result>/WEB-INF/jsp/test.jsp</result>
            <!--引用拦截器-->
            <interceptor-ref name="loginInterceptor"></interceptor-ref>
            <!--系统自带的拦截器也要运行，因为还有其他赋值、转换、校验、国际化等功能-->
            <interceptor-ref name="defaultStack"></interceptor-ref>
        </action>

        <action name="newTestAction" class="com.nf.action.NewTestAction">
            <result>/WEB-INF/jsp/new.jsp</result>
            <!--引用拦截器-->
            <interceptor-ref name="loginInterceptor"></interceptor-ref>
            <!--系统自带的拦截器也要运行，因为还有其他赋值、转换、校验、国际化等功能-->
            <interceptor-ref name="defaultStack"></interceptor-ref>
        </action>
    </package>
</struts>

action类UserAction不变，新增

package com.nf.action;


import com.nf.entity.User;
import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.interceptor.Interceptor;

import java.util.Map;

/*
定义拦截器有2种办法：
1.实现Interceptor接口
2.集成AbstractInterceptor抽象类
 */
public class LoginInterceptor implements Interceptor {

    public void destroy() {
        System.out.println("最后销毁");
    }

    public void init() {
        System.out.println("初始化");
    }

    public String intercept(ActionInvocation actionInvocation) throws Exception {
        System.out.println("有请求到了");
        System.out.println("进行校验，判断session是否为null");
        ActionContext context = ActionContext.getContext();
        Map<String, Object> session = context.getSession();
        User user = (User) session.get("user");
        if (user!=null){
            System.out.println("我是保安，检查过，此客户已经登录过");
            return actionInvocation.invoke();
        }else {
            System.out.println("我是保安，此客户没有登录过");
            return "login";
        }


    }
}

package com.nf.action;

import com.nf.entity.User;
import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;

import java.util.Map;

public class TestAction extends ActionSupport {
    @Override
    public String execute() throws Exception {
        System.out.println("保安说，已经检查过，直接进入test.jsp");
        return "success";

    }
}

package com.nf.action;

import com.opensymphony.xwork2.ActionSupport;

public class NewTestAction extends ActionSupport {
    @Override
    public String execute() throws Exception {

        return "success";
    }
}

地址：https://gitee.com/MuNianShi/user4.git