第十篇——Struts2的拦截器栈

时间：2022-12-18 12:00:19

拦截器栈：

从结构上看：拦截器栈相当于多个拦截器的组合；

从功能上看：拦截器栈也是拦截器。

默认拦截器栈：

在struts-core.jar包中的struts-default.xml中自定义了一个default拦截器栈，并且将其指定为默认拦截器栈；

只要定义包的过程中继承了struts-default包，那么默认defaultStack将是默认的拦截器

当包中的某个action显示指定某个拦截器，那么默认的拦截器将不会生效

拦截器栈中的各个拦截器的顺序很重要（一般将默认拦截器器栈放在前面）

项目实例：

1、项目结构

2、pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.ray</groupId>
  <artifactId>struts2Test</artifactId>
  <packaging>war</packaging>
  <version>1.0-SNAPSHOT</version>
  <name>struts2Test Maven Webapp</name>
  <url>http://maven.apache.org</url>

  <dependencies>

    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.apache.struts/struts2-core -->
    <dependency>
      <groupId>org.apache.struts</groupId>
      <artifactId>struts2-core</artifactId>
      <version>2.5.16</version>
    </dependency>

  </dependencies>

  <build>
    <finalName>struts2Test</finalName>
  </build>

</project>

3、web.xml

<web-app xmlns="http://java.sun.com/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
                      http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
         version="3.0" metadata-complete="true">
  <display-name>Archetype Created Web Application</display-name>

  <!-- 过滤所有请求交给Struts2处理 -->
  <filter>
    <filter-name>struts2</filter-name>
    <filter-class>
      org.apache.struts2.dispatcher.filter.StrutsPrepareAndExecuteFilter
    </filter-class>

     <!--action后缀（方法二）-->
    <!--<init-param>-->
      <!--<param-name>struts.action.extension</param-name>-->
      <!--<param-value>ray</param-value>-->
    <!--</init-param>-->
  </filter>

  <filter-mapping>
    <filter-name>struts2</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>

</web-app>

4、login4.jsp

<%@ taglib prefix="s" uri="/struts-tags" %>
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8" %>
<%
    String path = request.getContextPath();
    String basePath = request.getScheme() + "://" + request.getServerName() + ":" + request.getServerPort() + path + "/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
    <base href="<%=basePath%>">

    <title>用户登录</title>

    <meta http-equiv="pragma" content="no-cache">
    <meta http-equiv="cache-control" content="no-cache">
    <meta http-equiv="expires" content="0">
    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    <meta http-equiv="description" content="This is my page">
    <!--
	<link rel="stylesheet" type="text/css" href="styles.css">
	-->

</head>

<body>
    <s:form action="login4" method="POST">
        <font color="red">${loginError}</font><br>
        用户名：<input type="text" name="username"><br>
        密  码：<input type="password" name="password"><br>
        <input type="submit" value="登录">
        <input type="reset" value="重置">
    </s:form>
</body>
</html>

5、manager.jsp

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8" %>
<%
    String path = request.getContextPath();
    String basePath = request.getScheme() + "://" + request.getServerName() + ":" + request.getServerPort() + path + "/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
    <base href="<%=basePath%>">

    <title>管理界面</title>

    <meta http-equiv="pragma" content="no-cache">
    <meta http-equiv="cache-control" content="no-cache">
    <meta http-equiv="expires" content="0">
    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    <meta http-equiv="description" content="This is my page">
    <!--
	<link rel="stylesheet" type="text/css" href="styles.css">
	-->

</head>

<body>
    欢迎进入管理页面，该页面只有登录用户才能访问！
</body>
</html>

6、LoginAction4.java

package com.ray.action;

import com.opensymphony.xwork2.ActionSupport;
import org.apache.struts2.interceptor.SessionAware;

import java.util.Map;

/**
 * Created by Ray on 2018/3/26 0026.
 **/
public class LoginAction4 extends ActionSupport implements SessionAware {

    private String username;
    private String password;
    private Map<String,Object> session;

    @Override
    public String execute() throws Exception {

        if("admin".equals(username) && "123".equals(password)){
            session.put("userInfo",username);
            session.remove("loginError");
            return SUCCESS;
        }else{
            session.put("loginError","用户名或密码错误");
            session.remove("userInfo");
            return "login";
        }
    }

    public void setSession(Map<String, Object> session) {
        this.session = session;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public Map<String, Object> getSession() {
        return session;
    }
}

7、AuthInterceptor.java

package com.ray.interceptor;

import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.interceptor.AbstractInterceptor;

import java.util.Map;

/**
 * Created by Ray on 2018/3/26 0026.
 **/
public class AuthInterceptor extends AbstractInterceptor {

    public String intercept(ActionInvocation invocation) throws Exception {

        //获取session
        ActionContext context = ActionContext.getContext();
        Map<String,Object> session = context.getSession();
        if(session.get("userInfo") != null){
            //已登录
            String result = invocation.invoke();
            return result;
        }else{
            //未登录
            session.put("loginError","请先登录");
            return "login";
        }
    }
}

8、tenth-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="default" extends="struts-default" namespace="/">

        <!-- 注册拦截器 -->
        <interceptors>
            <interceptor name="auth" class="com.ray.interceptor.AuthInterceptor"/>
            <interceptor-stack name="authStack">
                <interceptor-ref name="defaultStack"/>
                <interceptor-ref name="auth"/>
            </interceptor-stack>
        </interceptors>

        <!-- 通过此Action访问后台管理页面 -->
        <action name="auth">
            <result>/manager.jsp</result>
            <result name="login">/login4.jsp</result>
            <interceptor-ref name="authStack"/>
        </action>

        <action name="login4" class="com.ray.action.LoginAction4">
            <result>/manager.jsp</result>
            <result name="login">/login4.jsp</result>
        </action>
    </package>
</struts>

9、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>

    <!-- action后缀（方法一） -->
    <!--<constant name="struts.action.extension" value="ra"/>-->

    <package name="default" namespace="/" extends="struts-default">
        <!-- 默认action -->
        <default-action-ref name="404"/>
        <action name="404">
            <result>/404.jsp</result>
        </action>

        <action name="helloWorld" class="com.ray.action.HelloWorldAction">
            <result name="success">/success.jsp</result>
        </action>

    </package>

    <!--<include file="second-struts.xml"/>-->
    <!--<include file="third-struts.xml"/>-->
    <!--<include file="fourth-struts.xml"/>-->
    <!--<include file="seventh-struts.xml"/>-->
    <!--<include file="eighth-struts.xml"/>-->
    <!--<include file="ninth-struts.xml"/>-->
    <include file="tenth-struts.xml"/>
</struts>

10、页面效果

10.1 未登录直接访问

第十篇——Struts2的拦截器栈

10.2 登录成功

第十篇——Struts2的拦截器栈

10.3 登录成功后访问

第十篇——Struts2的拦截器栈

ok！

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