CRUD

由于重新安装ecplise，不小心将我之前写过的程序都弄丢了，现在重新写了一个增删改查简单版，效果如下；

数据库：

主页面：

增加：

删除：

修改：

查询：

目录如下：

代码如下：

Dao.java

  1 package dao;
  2 
  3 import java.sql.Connection;
  4 import java.sql.PreparedStatement;
  5 import java.sql.ResultSet;
  6 import java.util.ArrayList;
  7 import java.util.List;
  8 
  9 import database.Database;
 10 import util.User;
 11 
 12 public class Dao {
 13     //增加
 14     public boolean add(User user) {
 15         Connection conn=null;
 16         PreparedStatement pstm=null;
 17         boolean judge=false;
 18         try {
 19             conn=Database.getConnection();
 20             String sql="insert into crud(name,password,sex,phone) values(?,?,?,?)";
 21             pstm=conn.prepareStatement(sql);
 22             pstm.setString(1, user.getName());
 23             pstm.setString(2, user.getPassword());
 24             pstm.setString(3, user.getSex());
 25             pstm.setString(4,user.getPhone());
 26             //执行插入操作
 27             int num=pstm.executeUpdate();
 28             if(num>0) {
 29                 System.out.println("插入成功");
 30                 judge=true;
 31             }else {
 32                 System.out.println("插入失败");
 33                 judge=false;
 34             }
 35         }catch(Exception e) {
 36             e.printStackTrace();
 37         }finally {
 38             //SQL执行完成后释放相关资源
 39             Database.close(conn,pstm);
 40         }
 41         return judge;
 42     }
 43     //查询
 44     public List<User> find(){
 45         List<User> list=new ArrayList<>();
 46         Connection conn=null;
 47         ResultSet rs=null;
 48         PreparedStatement pstm=null;
 49         User user=null;
 50         try {
 51             conn=Database.getConnection();
 52             String sql="select * from crud";
 53             pstm=conn.prepareStatement(sql);
 54             rs=pstm.executeQuery();
 55             while(rs.next()) {
 56                 String name=rs.getString("name");
 57                 String password=rs.getString("password");
 58                 String sex=rs.getString("sex");
 59                 String phone=rs.getString("phone");
 60                 user=new User(name,password,sex,phone);
 61                 list.add(user);
 62                 
 63                 System.out.println("name:"+name);
 64                 System.out.println("password:"+password);
 65                 System.out.println("sex:"+sex);
 66                 System.out.println("phone:"+phone);
 67             }
 68         }catch(Exception e) {
 69             e.printStackTrace();
 70         }finally {
 71             Database.close(conn, pstm, rs);
 72         }
 73         return list;
 74     }
 75     //删除
 76     public boolean delete(String name) {
 77         Connection conn=null;
 78         PreparedStatement pstm=null;
 79         ResultSet rs=null;
 80         boolean judge=false;
 81         try {
 82             conn=Database.getConnection();
 83             String sql="delete from crud where name=?";
 84             pstm=conn.prepareStatement(sql);
 85             pstm.setString(1, name);
 86             int num=pstm.executeUpdate();
 87             if(num>0) {
 88                 System.out.println("删除成功");
 89                 judge=true;
 90             }else {
 91                 System.out.println("删除失败");
 92                 judge=false;
 93             }
 94         }catch(Exception e) {
 95             e.printStackTrace();
 96         }finally {
 97             //SQL执行完成后释放相关资源
 98             Database.close(conn,pstm,rs);
 99         }
100         return judge;
101     }
102     //修改
103     public List<User> alter(String name){
104         List<User> list=new ArrayList<>();
105         Connection conn=null;
106         ResultSet rs=null;
107         PreparedStatement pstm=null;
108         User user=null;
109         try {
110             conn=Database.getConnection();
111             String sql="select * from crud where name=?";
112             pstm=conn.prepareStatement(sql);
113             pstm.setString(1,name);
114             rs=pstm.executeQuery();
115             while(rs.next()) {
116                 String namee=rs.getString("name");
117                 String password=rs.getString("password");
118                 String sex=rs.getString("sex");
119                 String phone=rs.getString("phone");
120                 user=new User(namee,password,sex,phone);
121                 list.add(user);
122                 
123                 System.out.println("name:"+namee);
124                 System.out.println("password:"+password);
125                 System.out.println("sex:"+sex);
126                 System.out.println("phone:"+phone);
127             }
128         }catch(Exception e) {
129             e.printStackTrace();
130         }finally {
131             Database.close(conn, pstm, rs);
132         }
133         return list;
134     }
135     //修改——更新
136     public boolean update(User user,String judgename) {
137         Connection conn=null;
138         PreparedStatement pstm=null;
139         boolean judge=false;
140         try {
141             conn=Database.getConnection();
142             String sql="update crud set name=?,password=?,sex=?,phone=? where name=?";
143             pstm=conn.prepareStatement(sql);
144             pstm.setString(1, user.getName());
145             pstm.setString(2, user.getPassword());
146             pstm.setString(3, user.getSex());
147             pstm.setString(4,user.getPhone());
148             pstm.setString(5, judgename);
149             //执行插入操作
150             int num=pstm.executeUpdate();
151             if(num>0) {
152                 System.out.println("修改成功");
153                 judge=true;
154             }else {
155                 System.out.println("修改失败");
156                 judge=false;
157             }
158         }catch(Exception e) {
159             e.printStackTrace();
160         }finally {
161             //SQL执行完成后释放相关资源
162             Database.close(conn,pstm);
163         }
164         return judge;
165     }
166 }

Dao.java

Database.java

 1 package database;
 2 
 3 import java.sql.Connection;
 4 import java.sql.DriverManager;
 5 import java.sql.PreparedStatement;
 6 import java.sql.ResultSet;
 7 import java.sql.SQLException;
 8 
 9 public class Database {
10     public static final String url="jdbc:mysql://localhost:3306/crud";//URL
11     public static final String user="填写自己的用户名";//用户名
12     public static final String password="填写自己的密码";//密码
13     
14     /**
15      * 连接数据库
16      * @return
17      */
18     public static Connection getConnection(){
19         Connection conn=null;
20         try {
21             Class.forName("com.mysql.jdbc.Driver");//加载数据库驱动
22             conn=DriverManager.getConnection(url, user, password);
23             System.out.println("数据库连接成功！");
24         }catch(Exception e) {
25             e.printStackTrace();
26         }
27         return conn;
28     }
29     
30     /**
31      * 关闭数据库
32      */
33     public static void close(Connection conn,PreparedStatement pstm) {
34         
35         System.out.println("关闭SQL(conn,pstm)");
36         if(pstm!=null) {
37             try {
38                 pstm.close();
39             }catch(SQLException e) {
40                 e.printStackTrace();
41             }
42         }
43         
44         if(conn!=null) {
45             try {
46                 conn.close();
47             }catch(SQLException e) {
48                 e.printStackTrace();
49             }
50         }
51         
52     }
53     
54     public static void close(Connection conn,PreparedStatement pstm,ResultSet rs) {
55         
56         System.out.println("关闭SQL(conn,pstm,rs)");
57         if(pstm!=null) {
58             try {
59                 pstm.close();
60             }catch(SQLException e) {
61                 e.printStackTrace();
62             }
63         }
64         
65         if(conn!=null) {
66             try {
67                 conn.close();
68             }catch(SQLException e) {
69                 e.printStackTrace();
70             }
71         }
72         
73         if(rs!=null) {
74             try {
75                 rs.close();
76             }catch(SQLException e) {
77                 e.printStackTrace();
78             }
79         }
80         
81     }
82 }

Database.java

Servlet.java

  1 package servlet;
  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.Dao;
 13 import util.User;
 14 
 15 /**
 16  * Servlet implementation class Servlet
 17  */
 18 @WebServlet("/Servlet")
 19 public class Servlet extends HttpServlet {
 20     private static final long serialVersionUID = 1L;
 21        
 22     /**
 23      * @see HttpServlet#HttpServlet()
 24      */
 25     public Servlet() {
 26         super();
 27         // TODO Auto-generated constructor stub
 28     }
 29 
 30     Dao dao=new Dao();
 31     
 32     public void add(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
 33         response.setCharacterEncoding("UTF-8");
 34         request.setCharacterEncoding("UTF-8");
 35         
 36         String name=request.getParameter("name");
 37         String password=request.getParameter("password");
 38         String sex=request.getParameter("sex");
 39         String phone=request.getParameter("phone");
 40         
 41         System.out.println("name:"+name);
 42         System.out.println("password:"+password);
 43         System.out.println("sex:"+sex);
 44         System.out.println("phone:"+phone);
 45         
 46         User user=new User(name,password,sex,phone);
 47         
 48         if(dao.add(user)){
 49             System.out.println("添加成功");
 50             request.getRequestDispatcher("main.jsp").forward(request,response);
 51         }else {
 52             System.out.println("添加失败");
 53             request.getRequestDispatcher("add.jsp").forward(request,response);
 54         }
 55         
 56     }
 57     public void find(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
 58         response.setCharacterEncoding("UTF-8");
 59         request.setCharacterEncoding("UTF-8");
 60 
 61         List<User> list=dao.find();
 62         request.setAttribute("list", list);
 63         
 64         System.out.println("查询成功");
 65         request.getRequestDispatcher("find.jsp").forward(request,response);
 66         
 67     }
 68     public void delete(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
 69         response.setCharacterEncoding("UTF-8");
 70         request.setCharacterEncoding("UTF-8");
 71         
 72         List<User> list=dao.find();
 73         request.setAttribute("list", list);
 74         request.getRequestDispatcher("delete.jsp").forward(request,response);
 75         
 76     }
 77     public void delete_show(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
 78         response.setCharacterEncoding("UTF-8");
 79         request.setCharacterEncoding("UTF-8");
 80         
 81         String name=request.getParameter("name");
 82         System.out.println("name:"+name);
 83         
 84         if(dao.delete(name)){
 85             System.out.println("删除成功");
 86             request.getRequestDispatcher("main.jsp").forward(request,response);
 87         }else {
 88             System.out.println("删除失败");
 89             request.getRequestDispatcher("fail.jsp").forward(request,response);
 90         }
 91         
 92     }
 93     public void alter(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
 94         response.setCharacterEncoding("UTF-8");
 95         request.setCharacterEncoding("UTF-8");
 96         
 97         List<User> list=dao.find();
 98         request.setAttribute("list", list);
 99         request.getRequestDispatcher("alter.jsp").forward(request,response);
100         
101     }
102     public void alter_show(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
103         response.setCharacterEncoding("UTF-8");
104         request.setCharacterEncoding("UTF-8");
105         
106         String name=request.getParameter("name");
107         System.out.println("name:"+name);
108         List<User> list=dao.alter(name);
109         request.setAttribute("list", list);
110         System.out.println("进入修改界面成功");
111         request.getRequestDispatcher("update.jsp").forward(request,response);
112         
113     }
114     public void update(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
115         response.setCharacterEncoding("UTF-8");
116         request.setCharacterEncoding("UTF-8");
117         
118         String name=request.getParameter("name");
119         String judge=request.getParameter("judge");
120         String password=request.getParameter("password");
121         String sex=request.getParameter("sex");
122         String phone=request.getParameter("phone");
123         
124         System.out.println("name:"+name);
125         System.out.println("judge:"+judge);
126         System.out.println("password:"+password);
127         System.out.println("sex:"+sex);
128         System.out.println("phone:"+phone);
129         
130         User user=new User(name,password,sex,phone);
131         
132         if(dao.update(user,judge)){
133             System.out.println("修改成功");
134             request.getRequestDispatcher("main.jsp").forward(request,response);
135         }else {
136             System.out.println("修改失败");
137             request.getRequestDispatcher("fail.jsp").forward(request,response);
138         }
139         
140     }
141     
142     
143     /**
144      * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
145      */
146     protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
147         // TODO Auto-generated method stub
148         response.setCharacterEncoding("UTF-8");
149         request.setCharacterEncoding("UTF-8");
150         System.out.println("进入Servlet");
151         String method = request.getParameter("method");
152           System.out.println(method);
153           if("add".equals(method)) {
154               add(request,response);
155           }else if("find".equals(method)) {
156               find(request,response);
157           }else if("delete".equals(method)) {
158               delete(request,response);
159           }else if("delete_show".equals(method)) {
160               delete_show(request,response);
161           }else if("alter".equals(method)) {
162               alter(request,response);
163           }else if("alter_show".equals(method)) {
164               alter_show(request,response);
165           }else if("update".equals(method)) {
166               update(request,response);
167           }
168     }
169 
170     /**
171      * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
172      */
173     protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
174         // TODO Auto-generated method stub
175         doGet(request, response);
176     }
177 
178 }

Servlet.java

User.java

 1 package util;
 2 
 3 public class User {
 4     private String name;//用户名
 5     private String password;//密码
 6     private String sex;//性别
 7     private String phone;//电话
 8     
 9     public String getName() {
10         return name;
11     }
12     public void setName(String name) {
13         this.name = name;
14     }
15     public String getPassword() {
16         return password;
17     }
18     public void setPassword(String password) {
19         this.password = password;
20     }
21     public String getSex() {
22         return sex;
23     }
24     public void setSex(String sex) {
25         this.sex = sex;
26     }
27     public String getPhone() {
28         return phone;
29     }
30     public void setPhone(String phone) {
31         this.phone = phone;
32     }
33     
34     public User() {super();}
35     public User(String name,String password,String sex,String phone) {
36         super();
37         this.name=name;
38         this.password=password;
39         this.sex=sex;
40         this.phone=phone;
41     }
42     
43     @Override
44     public String toString() {
45         return "User{" +
46                 "name=" + name +
47                 ", password='" + password + '\'' +
48                 ", sex=" + sex +
49                 ", phone='" + phone + '\'' +
50                 '}';
51     }
52 
53 }

User.java

add.jsp

 1 <%@ page language="java" contentType="text/html; charset=UTF-8"
 2     pageEncoding="UTF-8"%>
 3 <!DOCTYPE html>
 4 <html>
 5 <head>
 6 <meta charset="UTF-8">
 7 <title>增加页面</title>
 8 </head>
 9 <body>
10 <form action="Servlet?method=add" method="post" >
11     <table align="center">
12         <tr>
13             <td>姓名：</td>
14             <td>
15                 <input type="text" id="name" name="name" placeholder="请输入姓名" >
16             </td>
17         </tr>
18         <tr>
19             <td>密码：</td>
20             <td>
21                 <input type="password" id="password" name="password" placeholder="请输入密码">
22             </td>
23         </tr>
24         <tr>
25             <td>性别：</td>
26             <td>
27                 <input type="radio" id="sex" name="sex" checked="checked" value="男">男
28                 <input type="radio" id="sex" name="sex" value="女">女
29             </td>
30         </tr>
31         <tr>
32             <td>电话：</td>
33             <td>
34                 <input type="text" id="phone" name="phone" placeholder="请输入电话">
35             </td>
36         </tr>
37     </table>
38     <table align="center">
39         <tr style="text-align: center">
40             <td><input type="submit" value="增加"></td>
41             <td><input type="reset" value="重置"></td>
42             <td><input type="button" value="返回" onclick="window.location.href='main.jsp'"></td>
43         </tr>
44     </table>
45 </form>
46 </body>
47 </html>

add.jsp

alter.jsp

 1 <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
 2 <%@ page language="java" contentType="text/html; charset=UTF-8"
 3     pageEncoding="UTF-8"%>
 4 <!DOCTYPE html>
 5 <html>
 6 <head>
 7 <meta charset="UTF-8">
 8 <title>修改界面</title>
 9 </head>
10 <body>
11 <form action="Servlet?method=alter" method="post" >
12     <table align="center">
13         <tr>
14             <th>姓名</th>
15             <th>密码</th>
16             <th>性别</th>
17             <th>电话</th>
18         </tr>
19         <c:forEach items="${list}" var="user">
20             <tr>
21                 <td>${user.name}</td>
22                 <td>${user.password}</td>
23                 <td>${user.sex}</td>
24                 <td>${user.phone}</td>
25                 <td><a href="Servlet?method=alter_show&name=${user.name}">修改</a></td>
26             </tr>
27         </c:forEach>
28     </table>
29 </form>
30 </body>
31 </html>

alter.jsp

delete.jsp

 1 <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
 2 <%@ page language="java" contentType="text/html; charset=UTF-8"
 3     pageEncoding="UTF-8"%>
 4 <!DOCTYPE html>
 5 <html>
 6 <head>
 7 <meta charset="UTF-8">
 8 <title>删除界面</title>
 9 </head>
10 <body>
11 <form action="Servlet?method=delete" method="post" >
12     <table align="center">
13         <tr>
14             <th>姓名</th>
15             <th>密码</th>
16             <th>性别</th>
17             <th>电话</th>
18         </tr>
19         <c:forEach items="${list}" var="user">
20             <tr>
21                 <td>${user.name}</td>
22                 <td>${user.password}</td>
23                 <td>${user.sex}</td>
24                 <td>${user.phone}</td>
25                 <td><a href="Servlet?method=delete_show&name=${user.name}">删除</a></td>
26             </tr>
27         </c:forEach>
28     </table>
29 </form>
30 </body>
31 </html>

delete.jsp

fail.jsp

 1 <%@ page language="java" contentType="text/html; charset=UTF-8"
 2     pageEncoding="UTF-8"%>
 3 <!DOCTYPE html>
 4 <html>
 5 <head>
 6 <meta charset="UTF-8">
 7 <title>失败</title>
 8 </head>
 9 <body>
10 失败
11 </body>
12 </html>

fail.jsp

find.jsp

 1 <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
 2 <%@ page language="java" contentType="text/html; charset=UTF-8"
 3     pageEncoding="UTF-8"%>
 4 <!DOCTYPE html>
 5 <html>
 6 <head>
 7 <meta charset="UTF-8">
 8 <title>查询界面</title>
 9 </head>
10 <body>
11 <form action="Servlet?method=find" method="post" >
12     <table align="center">
13         <tr>
14             <th>姓名</th>
15             <th>密码</th>
16             <th>性别</th>
17             <th>电话</th>
18         </tr>
19         <c:forEach items="${list}" var="user">
20             <tr>
21                 <td>${user.name}</td>
22                 <td>${user.password}</td>
23                 <td>${user.sex}</td>
24                 <td>${user.phone}</td>
25             </tr>
26         </c:forEach>
27     </table>
28 </form>
29 </body>
30 </html>

find.jsp

main.jsp

 1 <%@ page language="java" contentType="text/html; charset=UTF-8"
 2     pageEncoding="UTF-8"%>
 3 <!DOCTYPE html>
 4 <html>
 5 <head>
 6 <meta charset="UTF-8">
 7 <title>CRUD</title>
 8 </head>
 9 <body>
10 <table align="center">
11     <tr style="text-align: center">
12         <td><input type="button" value="增加" onclick="window.location.href='add.jsp'"></td>
13     </tr>
14     <tr style="text-align: center">
15         <td><button onclick="window.location.href='Servlet?method=delete'">删除</button></td>
16     </tr>
17     <tr style="text-align: center">
18         <td><button onclick="window.location.href='Servlet?method=alter'">修改</button></td>
19     </tr>
20     <tr style="text-align: center">
21         <td><button onclick="window.location.href='Servlet?method=find'">查询</button></td>
22     </tr>
23 </table>
24 
25 </body>
26 </html>

main.jsp

update.jsp

 1 <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
 2 <%@ page language="java" contentType="text/html; charset=UTF-8"
 3     pageEncoding="UTF-8"%>
 4 <!DOCTYPE html>
 5 <html>
 6 <head>
 7 <meta charset="UTF-8">
 8 <title>修改页面</title>
 9 </head>
10 <body>
11 <form action="Servlet?method=update" method="post" >
12     <c:forEach items="${list}" var="user">
13     <table align="center">
14         <tr>
15             <td>姓名：</td>
16             <td>
17                 <input type="text" id="name" name="name" value="${user.name}">
18                 <input type="hidden" id="judge" name="judge" value="${user.name}">
19             </td>
20         </tr>
21         <tr>
22             <td>密码：</td>
23             <td>
24                 <input type="text" id="password" name="password" value="${user.password}">
25             </td>
26         </tr>
27         <tr>
28             <td>性别：</td>
29             <td>
30                 <input type="text" id="sex" name="sex" value="${user.sex}">
31             </td>
32         </tr>
33         <tr>
34             <td>电话：</td>
35             <td>
36                 <input type="text" id="phone" name="phone" value="${user.phone}">
37             </td>
38         </tr>
39     </table>
40     <table align="center">
41         <tr style="text-align: center">
42             <td><input type="submit" value="修改"></td>
43         </tr>
44     </table>
45 </c:forEach>
46 </form>
47 </body>
48 </html>

update.jsp

posted on 2021-02-25 23:27 一缕半夏微光阅读(147) 评论(0) 编辑收藏举报

会员力量，点亮园子希望

刷新页面返回顶部

一缕半夏微光

导航

公告

CRUD