Struts07---访问servlet的API

01.创建登录界面

<%@ 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 'index.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>
  <form action="user/login" method="post">
       <table>
            <tr>
               <td>用户名：</td>
               <td><input  type="text" name="name"/></td>
            </tr>
            <tr>
               <td>密码：</td>
               <td><input  type="password" name="password"/></td>
            </tr>
            <tr>
               <td></td>
               <td><input  type="submit" value="登录"/></td>
            </tr>
       </table>
   </form>

  </body>
</html>

02.配置struts.xml文件

<?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"/>
 
    <package name="default"  namespace="/user" extends="struts-default">
       <action name="login" class="cn.bdqn.action.UserAction" method="login">
           <result>/success.jsp</result>
      </action>
    </package>
</struts>

03.创建对应的UserAction

package cn.bdqn.action;


import java.util.Map;

import javax.servlet.ServletContext;

import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;
/**
 *  用户登录的action
 *  jsp九大内置对象
 *  
 *  out
 *  page
 *  pageContext
 *  request
 *  response
 *  session
 *  application
 *  config
 *  exception
 */
public class UserAction extends ActionSupport{


/**
    public  String  login(){
          获取前台的值
          01.耦合方式  不推荐使用
        String name = ServletActionContext.getRequest().getParameter("name");
        String password = ServletActionContext.getRequest().getParameter("password");
        System.out.println(name);
        System.out.println(password);
        //放入作用域
        ServletActionContext.getRequest().setAttribute("name",name);
        ServletActionContext.getRequest().setAttribute("password",password);
        return  SUCCESS;
    }*/
    
    /**
     * 登录的方法
     02. 解耦两种方法  
            001. 使用ActionContext!
       sturts2在底层把我们的request,session,application用Map集合保存起来了！
     */
    private  String  name;
    private  String  password;
    
    public  String  login(){
    Map<String, Object> request=(Map<String, Object>) ActionContext.getContext().get("request");
    //让success.jsp获取数据
    request.put("name",name);//  等同于setAttribute("name",name); 
    request.put("password",password);
        return  SUCCESS;
    }

    
    
    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getPassword() {
        return password;
    }

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

    
}

04.使用第二种解耦的方式，就是实现对应的Aware接口

import org.apache.struts2.interceptor.RequestAware;
import com.opensymphony.xwork2.ActionSupport;
/**
 *  实现对应的Aware接口
 */
public class UserAction2 extends ActionSupport implements RequestAware{

    private  String  name;
    private  String  password;
    private Map<String, Object> request;  //并不用写 set和get
    
    //登录的方法
    public  String  login(){
    request.put("name",name); 
    request.put("password",password);
        return  SUCCESS;
    }

    //重写方法   给请求request赋值
    @Override
    public void setRequest(Map<String, Object> request) {
        this.request=request;
        
    }
    
    
    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getPassword() {
        return password;
    }

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



    
    

    
}

05.success.jsp

===============el表达式获取数据=============<br/>
  ${name}
  ${password} <br/>
   ===============struts2标签获取数据=============<br/>
   <s:property value="password"/> <%--值栈中获取的    --%>
   <s:property value="#request.password"/>  <%--栈的上下文中获取的    --%>
   <s:property value="#attr.password"/>