Struts---访问servlet的API

小灰灰 2021-03-26 14:44 516阅读 0赞

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">
        
      </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"/>