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求帮助!新增不能新增,变成了修改登录的用户的信息。找不到原因

-1
[已解决问题] 解决于 2017-04-23 19:40
package UserServlet;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import dao.impl.UserDAOImpl;
import domain.User;

//登录功能
@WebServlet("/login")
public class LoginServlet extends HttpServlet{
    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        req.setCharacterEncoding("utf-8");
        resp.setContentType("text/html;charset=utf-8");
        String name = req.getParameter("name");
        String password = req.getParameter("pwd");
        UserDAOImpl udi = new UserDAOImpl();
        //调用登录方法
        User user = udi.login(name, password);
        //判断密码错误还是账号问题
        if (user == null) {
            req.setAttribute("error", "没有此用户,请检查用户名!");
            req.getRequestDispatcher("/Login.jsp").forward(req, resp);
        } else if (name.equals(user.getUsername()) && password.equals(user.getPassword())) {
            req.getSession().setAttribute("user", user);
            //req.getRequestDispatcher("/user?cmd=list").forward(req, resp);
            resp.sendRedirect("/user?cmd=list");
        } else {
            req.setAttribute("passworderror", "您的密码有误,请检查!");
            req.getRequestDispatcher("/Login.jsp").forward(req, resp);
        }
        
        
    }
}

 

流程是,先从Login.jsp进去,然后登陆。登录成功转到UserList.jsp-->这个表里可以做增加用户,删除用户,和修改用户 以及注销账户的操作。之前没做登录和注销功能的时候,添加一直可以正常添加。但是做了之后,一点添加的连接就变成了修改登录的用户。不能添加了。。。我找了好久,试了改变路径也不对,我猜测是因为新增和修改是做了一个判断(在save的Servlet里),然后里面的判断不起作用了。登陆的时候传进来的User跑到新增里面了。所以一点击就是修改登陆的用户的信息,而不是新增?但是不报错。,实在不知道该改哪里了?求大佬们帮我看看

这个是增删改查的Servlet

 1 package UserServlet;
 2 
 3 import java.io.IOException;
 4 import java.util.List;
 5 
 6 import javax.servlet.ServletException;
 7 import javax.servlet.annotation.WebServlet;
 8 import javax.servlet.http.HttpServlet;
 9 import javax.servlet.http.HttpServletRequest;
10 import javax.servlet.http.HttpServletResponse;
11 
12 import dao.impl.UserDAOImpl;
13 import domain.User;
14 
15 //合并
16 @WebServlet("/user")
17 public class UserServlet extends HttpServlet{
18     @Override
19     protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
20         req.setCharacterEncoding("utf-8");
21         resp.setContentType("text/html;utf-8");
22         //权限控制,如若取到的用户为空,则返回登录页面.
23         User user = (User)req.getSession().getAttribute("user");
24         if (user == null) {
25             resp.sendRedirect("/Login.jsp");
26             return;
27         }
28         String cmd = req.getParameter("cmd");
29         if ("list".equals(cmd)) {
30             this.list(req, resp);
31         }else if ("edit".equals(cmd)) {
32             this.edit(req, resp);
33         }else if ("save".equals(cmd)) {
34             this.save(req, resp);
35         }else {
36             this.delete(req, resp);
37         }
38     }
39     //新增
40     protected void save(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
41         req.setCharacterEncoding("utf-8");
42         resp.setContentType("text/html;utf-8");
43         String id = req.getParameter("id");
44         String name = req.getParameter("name");
45         String pwd = req.getParameter("pwd");
46         Integer age = Integer.valueOf(req.getParameter("age"));
47         UserDAOImpl udi = new UserDAOImpl();
48         User user = new User();
49         user.setUsername(name);
50         user.setPassword(pwd);
51         user.setAge(age);
52         if (id != null && !id.equals("")) {
53             //这个条件证明有id,所以是修改这条数据
54             user.setId(Integer.valueOf(id));
55             udi.update(user);
56         } else {
57             //不满足就是没id,就属于新增的数据
58             udi.save(user);
59         }
60         req.getRequestDispatcher("/user?cmd=list").forward(req, resp);;
61     }
62     //查询一条,修改
63     protected void edit(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
64         String id = req.getParameter("id");
65         UserDAOImpl udi = new UserDAOImpl();
66         User user = udi.queryOne(Integer.valueOf(id));
67         req.setAttribute("user", user);
68         req.getRequestDispatcher("/Add.jsp").forward(req, resp);
69     }
70     //删除
71     protected void delete(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
72         req.setCharacterEncoding("utf-8");
73         resp.setContentType("text/html;utf-8");
74         int id = Integer.parseInt(req.getParameter("id"));
75         UserDAOImpl udi = new UserDAOImpl();
76         udi.delete(id);
77         resp.sendRedirect("/user?cmd=list");
78     }
79     //查询全部数据
80     protected void list(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
81         req.setCharacterEncoding("utf-8");
82         resp.setContentType("text/html;charset=utf-8");
83         UserDAOImpl dao = new UserDAOImpl();
84         List<User> userlist = dao.queryAll();
85         req.setAttribute("userlist", userlist);
86         req.getRequestDispatcher("/UserList.jsp").forward(req, resp);
87         
88     }
89 }
package dao.impl;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;


import dao.IUserDAO;
import domain.User;

public class UserDAOImpl implements IUserDAO{
    //增删改方法抽取
    public void change(String sql, Object...params){
        Connection conn = null;
        PreparedStatement ps = null;
        try {
            JDBCTools jt = JDBCTools.getInstance();
            conn = jt.getConnection();
            ps = conn.prepareStatement(sql);
            for (int i = 1; i <= params.length; i++) {
                ps.setObject(i, params[i-1]);
            }
            ps.executeUpdate();
            
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            JDBCTools.getInstance().close(null, ps, conn);
        }
    }
    //增加
    @Override
    public void save(User user) {
        Connection conn = null;
        PreparedStatement ps = null;
        try {
            conn = JDBCTools.getInstance().getConnection();
            ps = conn.prepareStatement("insert into user (username, password, age) values(?, ?, ?)");
            //ps.setInt(1, user.getId());
            ps.setString(1, user.getUsername());
            ps.setString(2, user.getPassword());
            ps.setInt(3, user.getAge());
            ps.executeUpdate();
            
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            JDBCTools.getInstance().close(null, ps, conn);
        }
    }
    //修改
    @Override
    public void update(User user) {
        Connection conn = null;
        PreparedStatement ps = null;
        try {
            conn = JDBCTools.getInstance().getConnection();
            ps = conn.prepareStatement("update user set username=?, password=?, age=? where id=?");
            ps.setString(1, user.getUsername());
            ps.setString(2, user.getPassword());
            ps.setInt(3, user.getAge());
            ps.setInt(4, user.getId());
            ps.executeUpdate();
            
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            JDBCTools.getInstance().close(null, ps, conn);
        }
    }
    //删除
    @Override
    public void delete(int id) {
        Connection conn = null;
        PreparedStatement ps = null;
        try {
            conn = JDBCTools.getInstance().getConnection();
            ps = conn.prepareStatement("delete from user where id= ?");
            ps.setInt(1, id);
            ps.executeUpdate();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            JDBCTools.getInstance().close(null, ps, conn);
        }
    }
    //查询一个
    @Override
    public User queryOne(int id) {
        Connection conn = null;
        PreparedStatement ps = null;
        ResultSet rs = null;
        User user = null;
        try {
            conn = JDBCTools.getInstance().getConnection();
            ps = conn.prepareStatement("select * from user where id= ?");
            ps.setInt(1, id);
            rs = ps.executeQuery();
            while(rs.next()) {
                user = new User();
                user.setUsername(rs.getString("username"));
                user.setPassword(rs.getString("password"));
                user.setAge(rs.getInt("age"));
                user.setId(rs.getInt("id"));
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            JDBCTools.getInstance().close(null, ps, conn);
        }
        return user;
    }
    //查询全部
    @Override
    public List<User> queryAll() {
        Connection conn = null;
        PreparedStatement ps = null;
        ResultSet rs = null;
        User user = null;
        List<User> list = new ArrayList<User>();
        try {
            conn = JDBCTools.getInstance().getConnection();
            ps = conn.prepareStatement("select * from user");
            rs = ps.executeQuery();
            while(rs.next()) {
                user = new User();
                user.setUsername(rs.getString("username"));
                user.setPassword(rs.getString("password"));
                user.setAge(rs.getInt("age"));
                user.setId(rs.getInt("id"));
                list.add(user);
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            JDBCTools.getInstance().close(null, ps, conn);
        }
        return list;
    }
    //登录方法
    @Override
    public User login(String username, String password) {
        Connection conn = null;
        PreparedStatement ps = null;
        ResultSet rs = null;
        User user = null;
        try {
            conn = JDBCTools.getInstance().getConnection();
            ps = conn.prepareStatement("select * from user where username= ?");
            //用传入的用户名和数据库里的对比,如果有则返回一个用户,没有返回空
            ps.setString(1, username);
            rs = ps.executeQuery();
            if (rs != null) {
                while(rs.next()) {
                    user = new User();
                    user.setUsername(rs.getString("username"));
                    user.setPassword(rs.getString("password"));
                    user.setAge(rs.getInt("age"));
                    user.setId(rs.getInt("id"));
                }
                return user;
            } 
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            JDBCTools.getInstance().close(null, ps, conn);
        }
        return user;
    }

}
<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>登录页面</title>
</head>
<body>
<form action="/login" method="post">
用户名<input type="text" name="name"/><br/>
密码<input type="password" name="pwd"/><br/>
<input type="submit" value="登入" /><br/>
</form>
${error}
${passworderror}
</body>
</html>
<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
<style type="text/css">
    table,tr,th,td{
    border: 1px solid black;
    border-collapse: collapse;
    margin-top: auto;
    }
</style>
</head>
<body>
恭喜${user.username}登陆成功!<a href="/logout">注销</a><br/>
<a href="/Add.jsp">添加数据</a><br/>
<table>
  <tr>
    <th>id</th>
    <th>用户名</th>
    <th>密码</th>
    <th>年龄</th>
    <th>操作</th>
  </tr>

 <c:forEach items="${userlist}" var="user">
  <tr>
       <td>${user.id}</td>
       <td>${user.username}</td>
    <td>${user.password}</td>
    <td>${user.age}</td>
    <td><a href="/user?cmd=delete&id=${user.id}">删除</a>/<a href="/user?cmd=edit&id=${user.id}">修改</a></td>
  </tr>
 </c:forEach>
</table>

</body>
</html>
复制代码
<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>修改页面</title>
</head>
<body>
<form action="/user?cmd=save" method="post">
<input type="hidden" type="text" name="id" value="${user.id}">
用户名<input type="text" name="name" value="${user.username}"/><br>
密码<input type="password" name="pwd" value="${user.password}"/><br>
年龄<input type="text" name="age" value="${user.age}"/><br>
<input type="submit" name="sub" value="提交"/>
</form>
</body>
</html>
复制代码
问题补充:

我把登录和权限控制那里注释了就又可以添加了,我猜想是因为,我在判断登录的方法的时候,如果成功了就返回一个对象,然后把这个对象放在session里,是不是由于这个USER对象存在,所以在判断是否修改的那里,由于有ID,所以就判定为是修改。。然后jsp里value里的值读取的也是登录用户的信息。。

InewBee的主页 InewBee | 初学一级 | 园豆:191
提问于:2017-04-22 20:30
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最佳答案
0

登录对应的Servlet怎么没看到啊,应该就是登录就应的Servlet写得有问题导致的

奖励园豆:5
狼爷 | 小虾三级 |园豆:1204 | 2017-04-23 10:17

上传了。感觉没问题啊,因为是从list开始添加数据的

InewBee | 园豆:191 (初学一级) | 2017-04-23 18:28

解决了,就是因为判断修改的那里把登录用户的id穿进去了,所以判定为修改。谢谢

InewBee | 园豆:191 (初学一级) | 2017-04-23 19:38
其他回答(1)
0

1,先打印出变量cmd的值,看看是否符合新增的条件。,2,调试一下,看看在哪里调用的

代码飞了 | 园豆:470 (菜鸟二级) | 2017-04-23 11:12

我试下

支持(0) 反对(0) InewBee | 园豆:191 (初学一级) | 2017-04-23 18:29

解决了,就是因为判断修改的那里把登录用户的id穿进去了,所以判定为修改。谢谢

支持(0) 反对(0) InewBee | 园豆:191 (初学一级) | 2017-04-23 19:38
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