controller
package com.bh.controller;
import com.bh.po.User;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;
import java.util.HashMap;
@Controller
public class ShowController {
/*
* 方式1:原始方式
* */
/* @RequestMapping("/show1.do")
public String show1(HttpServletRequest request, HttpServletResponse response){
String username="tom";
String password="123";
request.setAttribute("userName",username);
request.setAttribute("pwd",password);
return "/result1.jsp";
}*/
/*
* 方式2： 使用ModelMap
*
* */
/* @RequestMapping("/show2.do")
public String show2(ModelMap mod){
mod.put("userName","tom1");
mod.put("pwd","4444");
return "result1.jsp";
}*/
/*
* 方式3：使用ModelAndView
* */
/*@RequestMapping("/show3.do")
public ModelAndView show3(){
HashMap<String,String> rstMap = new HashMap<>();
rstMap.put("userName","jerry");
rstMap.put("pwd","45612");
ModelAndView mv = new ModelAndView("result1.jsp", rstMap);
return mv;
}*/
/*
*
* 方式4： 使用@ModelAttribute
注意： 只要有@ModelAttribute注解的话，
那么这个Contgroller里面所有的url的方法都会先执行
这个加了注解的方法
* */
@RequestMapping("/show4.do")
public String show4(){
System.out.println("start========");
System.out.println("end=============");
return "/result1.jsp";
}
@ModelAttribute(value = "u1")
public User getUser(){
User u1 = new User();
u1.setUsername("tom");
u1.setPassword("123456a?");
return u1;
}
}
User
package com.bh.po;
public class User {
private String username;
private String password;
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;
}
}
result1.jsp
<%@ page import="com.bh.po.User" %><%--
Created by IntelliJ IDEA.
User: liangkuan
Date: 2023/6/5
Time: 19:43
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
username:<%=request.getAttribute("userName")%><br>
password:<%=request.getAttribute("pwd")%><br>
<%--方式四--%>
<p><%=((User)request.getAttribute("u1")).getUsername()%></p>
<p><%=((User)request.getAttribute("u1")).getPassword()%></p>
</body>
</html>