在eclipse中，java-ee curd程序更新不起作用。

Question

我现在正在对eclipse java-ee进行编码，在curd mvc程序中，我已经生成了四种方法，除了更新方法之外，编译时我可以读取数据，但是当我更新时，我得到了错误400，我给出了我的控制器和道类。

我的控制器

----------

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.``ModelAttribute;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.servlet.ModelAndView;
import java.util.List;
import dao.UserDaoImpl;
import model.User;



@Controller
public class Firstcontroller  {

    @Autowired
    UserDaoImpl userDao;

    @RequestMapping(value="/add")
    public ModelAndView redirectUser()
    {
        ModelAndView m=new ModelAndView("add");
        return m;
    }


    @RequestMapping(value="/table")
    public ModelAndView viewUser()
    {
        List<User> list=userDao.viewUsers();
        return new ModelAndView("All_User","list",list);

    }

    @RequestMapping(value="/register",method=RequestMethod.POST)
    public ModelAndView processSaveUser(@ModelAttribute User user)
    {
        if(userDao.saveUser(user))
        {
            ModelAndView m=new ModelAndView("login","response","Successfully Registered");
            return m;
        }

        ModelAndView m1=new ModelAndView("signup","response","Failed Registeration");
        return m1;

    }

    @RequestMapping(value="deleteuser/{id}" ,method = RequestMethod.GET)
    public ModelAndView deleteuser(@PathVariable int id)
    {
        userDao.delete(id);
        return new ModelAndView("redirect:/table");  
    }

    @RequestMapping(value="/edituser/{id}")  
    public ModelAndView edit(@PathVariable int id){  

       User user=userDao.getUserById(id);
        return new ModelAndView("edituser","command",user);  
    }  

    @RequestMapping(value="/save",method = RequestMethod.POST)  
    public ModelAndView edituser(@PathVariable String id){  
        System.out.println("Got In");
        //userDao.update(user);  
        return new ModelAndView("redirect:/table");  
}
}

我的刀是

    package dao;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List;

import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;

import handler.UserRowMapper;
import model.User;

public class UserDaoImpl implements UserDao {

    private JdbcTemplate jdbcTemp;

    public void setJdbcTemp(JdbcTemplate jdbcTemp) {
        this.jdbcTemp = jdbcTemp;
    }



    public boolean saveUser(User user) {
        String sql_query="INSERT INTO userdata (username,password) VALUES (?,?)";
        int x=jdbcTemp.update(sql_query,user.getLunm(),user.getLpwd());
        if(x>0)
        {
            return true;
        }
        return false;
    }

    public List<User>viewUsers()
    {
        return jdbcTemp.query("select * from userdata",new RowMapper<User>()
                {
                  public User mapRow(ResultSet rs,int row)throws SQLException
                  {
                      User u=new User();
                      u.setId(rs.getInt(1));
                      u.setLunm(rs.getString(2));
                      u.setLpwd(rs.getString(3));
                      return u;
                  }
                }
                ); 
    }

    public User getUserById(int id)
    {
        String sql="select * from userdata where id=?";
        return (User)jdbcTemp.queryForObject(sql,new Object[]{id},new UserRowMapper());
    }


    public int delete(int id)
    {
        String sql="delete from userdata where id=?";
        int x=jdbcTemp.update(sql,id);
        if(x>0)
        {
            return(x);
        }
        return (0);
    }

    public int update(User user)
    {
        String sql="update userdetails set username=? and password=? where id=?";
        return jdbcTemp.update(sql,user.getLunm(),user.getLpwd(),user.getId());
    }
}

EditUser.jsp

<%@ taglib uri="http://www.springframework.org/tags/form" prefix="form"%>  
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>  
<%@ page isELIgnored="false" %>
        <h1>Edit User</h1>
        <h1>${command.id }</h1>
       <form:form method="POST" action="save?id=${command.id }">  
        <table >  
        <tr>
        <td></td>  
         <td><form:hidden  path="id" /></td>
         </tr> 
         <tr>  
          <td>Username : </td> 
          <td><form:input path="lunm"  /></td>
         </tr>  
         <tr>  
          <td>password :</td>  
          <td><form:input path="lpwd" /></td>


         <tr>  
          <td> </td>  
          <td><input type="submit" value="Edit" /></td>  
         </tr>  
        </table>  
       </form:form> [ this is my error msg][1]

从表中获取值

Answer 1

 @RequestMapping(value="/save",method = RequestMethod.POST)  
 public ModelAndView edituser(@PathVariable String id){  
    System.out.println("Got In");
    //userDao.update(user);  
    return new ModelAndView("redirect:/table");  
 }

如果上面的代码用于商店，更新后的用户名和密码意味着将@PathVariable更改为@ModelAttribute用户，例如：

 @RequestMapping(value="edituser/save",method = RequestMethod.POST)  
   //@RequestMapping(value="/save",method=RequestMethod.PUT)
 public ModelAndView edituser(@ModelAttribute User user){  
    System.out.println("Got In");
    userDao.update(user);  
    return new ModelAndView("redirect:/table");  
 }

有不同的表名

public int delete(int id)
    {
    String sql="delete from userdata where id=?";
    int x=jdbcTemp.update(sql,id);
    if(x>0)
    {
        return(x);
    }
    return (0);
}


public int update(User user)
{
    String sql="update userdata set username=?,password=? where id=?";
    return jdbcTemp.update(sql,user.getLunm(),user.getLpwd(),user.getId());
}