springmvc 梳理5--传参

再也不用 getParamter 了

1. 建一个User类

package com.xinzhi.entity;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import org.springframework.beans.factory.annotation.Autowired;

/**
 * @author sr
 * @date 2021/1/25
 */
@Data
@AllArgsConstructor
@NoArgsConstructor
public class User {
    private int id;
    private String username;
    private String password;
}

2. 修改FirstController.java

@RequestMapping(value = "/add",method = RequestMethod.POST)
    public String addUser(User user) throws Exception {
    //模型里封装数据
        System.out.println(user);
        return "hellomvc";
    }

要什么，加什么

    @RequestMapping(value = "/add",method = RequestMethod.POST)
    public String addUser(User user,HttpServletRequest request) throws Exception {
    //模型里封装数据
        request.setAttribute("user",user);
        System.out.println(user);
        return "add";
    }

或这样

public class FirstController {
    @RequestMapping(value = "/add")
    public String addUser(Integer id,String username,String password,HttpServletRequest request) throws Exception {
    //模型里封装数据
        request.setAttribute("user",new User(id,username,password));
        
        return "hellomvc";
    }

但如果这个参数名跟user类的私有变量不一样，就传不过去

 解决方法：

3. 在index.jsp里面做个表单

<form action="/user/add" method="post">
    <input name="id" >
    <input name="username">
    <input name="password">
    <input type="submit" value="提交">
</form>

4.测试

成功