Struts2框架实现简单的用户登入

Struts框架汲取了Struts的优点，以WebWork为核心，拦截器，可变和可重用的标签。

第一步：加载Struts2 类库：

第二步：配置web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" 
    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_2_5.xsd">
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
  
  <!-- 配置Struts2过滤器 :拦截请求 -->
  <filter>
      <filter-name>Struts2</filter-name>
      <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
  </filter>
  <filter-mapping>
      <filter-name>Struts2</filter-name>
      <url-pattern>/*</url-pattern><!--'/*' 过滤所有请求 -->
  </filter-mapping>
  
</web-app>

第三步：开发视图层页面（提交表单页）

<%@ 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>Struts2Demo</title>
    
  </head>
  
  <body>
    <h1>HelloWorld Struts2</h1>
    <hr>
    <form action="LonginAction" method="post">
        <p>用户名：<input type="text" name="username" /></p>
        <p>密   码：<input type="password" name="password" /></p>
        <p><input type="submit" /></p>
    </form>
  </body>
</html>
四：三层架构：
package dao;
/**
 * 用户操作接口
 * @author Administrator
 *
 */
public interface UserDao {
    
    public String login(String username,String password);

}
package biz;
/**
 * 用户业务接口
 * @author Administrator
 *
 */
public interface UserBiz {
    
    public String login(String username,String password);

}
package biz.impl;

import biz.UserBiz;
import dao.UserDao;
import dao.UserDaoImpl;

public class UserBizImpl implements UserBiz {
    
    //创建dao层对象
    UserDao userdao = new UserDaoImpl();
    
    /**
     * 调用dao层方法
     */
    
    public String login(String username, String password) {
        
        return userdao.login(username, password);
    }

}
package dao;

public class UserDaoImpl implements UserDao {

    public String login(String username, String password) {
        String str = "";
        if(username.equals("msit") && password.equals("123456")){
            str = "success";
        }else{
            str = "error";
        }
        
        // TODO Auto-generated method stub
        return str;
    }

}

第五步：开发控制层Action

package Action;

import java.util.Map;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.apache.struts2.ServletActionContext;

import biz.UserBiz;
import biz.impl.UserBizImpl;

import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;

/**
 * 登录控制器
 * @author Administrator
 *
 */
public class LoginAction extends ActionSupport{
    
    /*值栈：页面可以直接获取*/
    String username;//form表单name；进行封装
    String password;//form表单name；进行封装
    
    //创建Biz层对象
    UserBiz userbiz = new UserBizImpl();
    
    
    
    
    /* (non-Javadoc)
     * @see com.opensymphony.xwork2.ActionSupport#execute()
     */
    @Override
    public String execute() throws Exception {
        // TODO Auto-generated method stub
        System.out.println(username+"==="+password);
        
        /*解耦(降低依赖)方式;基于Map集合*/
        ActionContext ac = ActionContext.getContext();
        /*得到request*/
        Map request = (Map) ac.get("request");
        //request.put("username", username);
        /*得到session*/
        Map session = ac.getSession();
        /*得到application*/
        Map application = ac.getApplication();
        //===================================================
        /*耦合(依懒性)方式*/
        HttpServletRequest request2 = ServletActionContext.getRequest();
        HttpServletResponse response = ServletActionContext.getResponse();
        HttpSession session2 = request2.getSession();
        
        //request2.setAttribute("username", username);
        
        /**
         * struts默认提供了五个状态字符串
         */
        return userbiz.login(username, password);
    }
    
    
    /**
     * @return the username
     */
    public String getUsername() {
        return username;
    }

    /**
     * @param username the username to set
     */
    public void setUsername(String username) {
        this.username = username;
    }

    /**
     * @return the password
     */
    public String getPassword() {
        return password;
    }

    /**
     * @param password the password to set
     */
    public void setPassword(String password) {
        this.password = password;
    }
}

第六步：配置struts.xml(核心文件)；可以参照struts-default.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>
        <!-- 配置包信息 -->
        <package name="default" namespace="/" extends="struts-default">
            <!-- 配置Action：关联Action JavaBean -->
            <action name="LonginAction" class="Action.LoginAction">
                <!-- 指定返回的视图 ;默认使用转发-->
                <result name="success">success.jsp</result>
                <result name="error">error.jsp</result>
            </action>
        </package>
    </struts>

第七步：处理完逻辑之后返回相应的字符串success、error跳转到相应的页面

<%@ 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>My JSP 'success.jsp' starting page</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>
   ${username } 登陆成功！！！ <br>
  </body>
</html>
<%@ 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>My JSP 'error.jsp' starting page</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>
    登录失败 <br>
  </body>
</html>

注意：

配置struts2
    1、加入类库（jar包）—从应用实例当中拷贝
    2、在web.xml中配置过滤器
        <!-- 配置Struts2过滤器  -->
          <filter>
            <filter-name>Struts2</filter-name>
            <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
          </filter>
          <filter-mapping>
            <filter-name>Struts2</filter-name>
            <url-pattern>/*</url-pattern><!--'/*' 过滤所有请求 -->
          </filter-mapping>
    
    3、编写页面index.jsp
    4、配置控制器（action） LoginAction  继承 Actionsupper
        重写父类的excute()方法

    5、配置struts.xml(核心文件)；可以参照struts-default.xml    

    6、处理完逻辑之后返回相应的字符串success、error跳转到相应的页面
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原文地址：https://www.cnblogs.com/wlx520/p/4581877.html