資料庫專案案例之---登入註冊和增刪改查
阿新 • • 發佈：2019-07-30
登入註冊和增刪改查
（一）功能
1.使用了普通的jdbc和資料庫連線池c3p0兩種技術
2.使用了三層架構dao層（資料訪問層），service層（業務邏輯層）和servlet層（請求控制層）
3.實現了增刪改查和登入註冊技術
（二）頁面展示
1.登入頁面
2.註冊頁面
3.登入成功頁面
4.登入失敗頁面
5.修改頁面
6.修改成功頁面
7.刪除成功頁面
（三）程式碼展示
（1）entity
1.User.java
package entity;
public class User {
private int id;
private String username;
private String password;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
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;
}
@Override
public String toString() {
return "User{" +
"id=" + id +
", username='" + username + '\'' +
", password='" + password + '\'' +
'}';
}
}
（2）util
1.JDBCUtils.java 普通jdbc
package util;
import com.mchange.v2.c3p0.ComboPooledDataSource;
import java.io.IOException;
import java.io.InputStream;
import java.sql.*;
import java.util.Properties;
public class JDBCUtils {
private static final String driverClass;
private static final String url;
private static final String username;
private static final String password;
static{
driverClass ="com.mysql.jdbc.Driver";
url ="jdbc:mysql://localhost:3306/zml";
username ="root";
password = "root";
}
/**
* 註冊驅動的方法
* @throws ClassNotFoundException
*/
public static void loadDriver() throws ClassNotFoundException{
Class.forName(driverClass);
}
/**
* 獲得連線的方法:
* @throws SQLException
*/
public static Connection getConnection() throws Exception{
loadDriver();
Connection conn = DriverManager.getConnection(url, username, password);
return conn;
}
/**
* 資源釋放
*/
public static void release(Statement stmt,Connection conn){
if(stmt != null){
try {
stmt.close();
} catch (SQLException e) {
e.printStackTrace();
}
stmt = null;
}
if(conn != null){
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
conn = null;
}
}
public static void release(ResultSet rs,Statement stmt,Connection conn){
if(rs!= null){
try {
rs.close();
} catch (SQLException e) {
e.printStackTrace();
}
rs = null;
}
if(stmt != null){
try {
stmt.close();
} catch (SQLException e) {
e.printStackTrace();
}
stmt = null;
}
if(conn != null){
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
conn = null;
}
}
}
2.JDBCUtils2.java 資料連線池c3p0
package util;
import com.mchange.v2.c3p0.ComboPooledDataSource;
import javax.sql.DataSource;
import java.beans.PropertyVetoException;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
/**
* 資料連線池c3p0
*/
public class JDBCUtils2 {
private static final ComboPooledDataSource dataSource = new ComboPooledDataSource();
static{
try {
dataSource.setDriverClass("com.mysql.jdbc.Driver");
dataSource.setJdbcUrl("jdbc:mysql://localhost:3306/zml");
dataSource.setUser("root");
dataSource.setPassword("root");
} catch (PropertyVetoException e) {
e.printStackTrace();
}
}
/**
* 獲得連線的方法:
* @throws SQLException
*/
public static Connection getConnection() throws Exception{
Connection conn = dataSource.getConnection();
return conn;
}
/**
* 資源釋放
*/
public static void release(Statement stmt, Connection conn){
if(stmt != null){
try {
stmt.close();
} catch (SQLException e) {
e.printStackTrace();
}
stmt = null;
}
if(conn != null){
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
conn = null;
}
}
public static void release(ResultSet rs, Statement stmt, Connection conn){
if(rs!= null){
try {
rs.close();
} catch (SQLException e) {
e.printStackTrace();
}
rs = null;
}
if(stmt != null){
try {
stmt.close();
} catch (SQLException e) {
e.printStackTrace();
}
stmt = null;
}
if(conn != null){
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
conn = null;
}
}
}
（3）dao
1.LoginDao.java
package dao;
import util.JDBCUtils;
import util.JDBCUtils2;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
public class LoginDao {
public boolean getLogin(String username,String password){
Connection conn=null;
PreparedStatement pstmt=null;
ResultSet rs=null;
boolean flag=false;
try{
//獲得連線
conn = JDBCUtils2.getConnection();
//編寫sql
String sql="select password from user where username=? and password=?";
//預編譯sql
pstmt=conn.prepareCall(sql);
pstmt.setString(1,username);
pstmt.setString(2,password);
//設定引數
//執行sql
rs=pstmt.executeQuery();
if(rs.next()){
flag=true;
}else{
flag=false;
}
}catch (Exception e){
}finally {
JDBCUtils2.release(rs,pstmt,conn);
}
return flag;
}
}
package util;
import com.mchange.v2.c3p0.ComboPooledDataSource;
import javax.sql.DataSource;
import java.beans.PropertyVetoException;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
/**
* 資料連線池c3p0
*/
public class JDBCUtils2 {
private static final ComboPooledDataSource dataSource = new ComboPooledDataSource();
static{
try {
dataSource.setDriverClass("com.mysql.jdbc.Driver");
dataSource.setJdbcUrl("jdbc:mysql://localhost:3306/zml");
dataSource.setUser("root");
dataSource.setPassword("root");
} catch (PropertyVetoException e) {
e.printStackTrace();
}
}
/**
* 獲得連線的方法:
* @throws SQLException
*/
public static Connection getConnection() throws Exception{
Connection conn = dataSource.getConnection();
return conn;
}
/**
* 資源釋放
*/
public static void release(Statement stmt, Connection conn){
if(stmt != null){
try {
stmt.close();
} catch (SQLException e) {
e.printStackTrace();
}
stmt = null;
}
if(conn != null){
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
conn = null;
}
}
public static void release(ResultSet rs, Statement stmt, Connection conn){
if(rs!= null){
try {
rs.close();
} catch (SQLException e) {
e.printStackTrace();
}
rs = null;
}
if(stmt != null){
try {
stmt.close();
} catch (SQLException e) {
e.printStackTrace();
}
stmt = null;
}
if(conn != null){
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
conn = null;
}
}
}
2.RegisterDao.java
package dao;
import entity.User;
import util.JDBCUtils;
import util.JDBCUtils2;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;
public class RegisterDao {
public int getinsert(String username,String password){
Connection conn=null;
PreparedStatement pstmt=null;
int num=0;
try {
//獲得連線
conn = JDBCUtils2.getConnection();
//編寫sql
String sql="insert into user values(null,?,?)";
//預編譯sql
pstmt=conn.prepareCall(sql);
pstmt.setString(1,username);
pstmt.setString(2,password);
//設定引數
//執行sql
num=pstmt.executeUpdate();
} catch (Exception e) {
e.printStackTrace();
}finally {
JDBCUtils2.release(pstmt,conn);
}
return num;
}
}
3.UserDao.java
package dao;
import com.mchange.v2.c3p0.ComboPooledDataSource;
import entity.User;
import util.JDBCUtils;
import util.JDBCUtils2;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
public class UserDao {
public List<User> getSelect(){
Connection conn=null;
PreparedStatement pstmt=null;
ResultSet rs=null;
List<User> user=new ArrayList<User>();
User a=null;
try {
//獲得連線
conn = JDBCUtils2.getConnection();
//編寫sql
String sql="select * from user";
//預編譯sql
pstmt=conn.prepareCall(sql);
//設定引數
//執行sql
rs=pstmt.executeQuery();
while(rs.next()){
a=new User();
a.setId(rs.getInt(1));
a.setUsername(rs.getString(2));
a.setPassword(rs.getString(3));
user.add(a);
}
} catch (Exception e) {
e.printStackTrace();
}finally {
JDBCUtils.release(rs,pstmt,conn);
}
return user;
}
}
4.UpdateDao.java
package dao;
import entity.User;
import util.JDBCUtils2;
import java.sql.Connection;
import java.sql.PreparedStatement;
public class UpdateDao {
public int getUpdate(User user){
Connection conn=null;
PreparedStatement pstmt=null;
int num=0;
try {
//獲得連線
conn = JDBCUtils2.getConnection();
//編寫sql
String sql="update user set username=?,password=? where id=?";
//預編譯sql
pstmt=conn.prepareCall(sql);
pstmt.setString(1,user.getUsername());
pstmt.setString(2,user.getPassword());
pstmt.setInt(3,user.getId());
//設定引數
//執行sql
num=pstmt.executeUpdate();
} catch (Exception e) {
e.printStackTrace();
}finally {
JDBCUtils2.release(pstmt,conn);
}
return num;
}
}
5.DeleteDao.java
package dao;
import util.JDBCUtils2;
import java.sql.Connection;
import java.sql.PreparedStatement;
public class DeleteDao {
public int getDelete(int id){
Connection conn=null;
PreparedStatement pstmt=null;
int num=0;
try {
//獲得連線
conn = JDBCUtils2.getConnection();
//編寫sql
String sql="delete from user where id=?";
//預編譯sql
pstmt=conn.prepareCall(sql);
pstmt.setInt(1,id);
//設定引數
//執行sql
num=pstmt.executeUpdate();
} catch (Exception e) {
e.printStackTrace();
}finally {
JDBCUtils2.release(pstmt,conn);
}
return num;
}
}
（4）service
1.UserService.java
package service;
import dao.*;
import entity.User;
import java.util.List;
public class UserService {
public List<User> getServlet(){
return new UserDao().getSelect();
}
public boolean getLogin(String username,String password){
return new LoginDao().getLogin(username,password);
}
public int getinsert(String username,String password){
return new RegisterDao().getinsert(username,password);
}
public int getUpdate(User user){
return new UpdateDao().getUpdate(user);
}
public int getDelete(int id){
return new DeleteDao().getDelete(id);
}
}
（5）servlet
1.LoginServlet.java
package servlet;
import service.UserService;
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 java.io.IOException;
@WebServlet("/LoginServlet")
public class LoginServlet extends HttpServlet {
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
req.setCharacterEncoding("UTF-8");
String username=req.getParameter("username");
String password=req.getParameter("password");
UserService log=new UserService();
boolean pwd=log.getLogin(username,password);
System.out.println(password+" "+pwd);
if(pwd==true){
req.getRequestDispatcher("UserServlet").forward(req,resp);
}else{
req.getRequestDispatcher("error.jsp").forward(req,resp);
}
}
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
doPost(req, resp);
}
}
2.RegisterServlet.java
package servlet;
import service.UserService;
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 java.io.IOException;
@WebServlet("/RegisterServlet")
public class RegisterServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
doPost(req, resp);
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
req.setCharacterEncoding("UTF-8");
String username=req.getParameter("username");
String password=req.getParameter("password");
UserService u=new UserService();
int num=u.getinsert(username,password);
if(num>0){
req.getRequestDispatcher("index.jsp").forward(req,resp);
}else{
req.getRequestDispatcher("register.jsp").forward(req,resp);
}
}
}
3.UserServlet.java
package servlet;
import entity.User;
import service.UserService;
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 java.io.IOException;
import java.util.List;
@WebServlet("/UserServlet")
public class UserServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
doPost(req, resp);
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
UserService u=new UserService();
List<User> user=u.getServlet();
System.out.println("udrt"+user);
for(User uu:user){
System.out.println(uu.getId()+" "+uu.getUsername()+" "+uu.getPassword());
}
req.setAttribute("User",user);
req.getRequestDispatcher("success.jsp").forward(req,resp);
}
}
4.UpdateServlet.java
package servlet;
import dao.UserDao;
import entity.User;
import service.UserService;
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 java.io.IOException;
@WebServlet("/UpdateServlet")
public class UpdateServlet extends HttpServlet {
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
req.setCharacterEncoding("UTF-8");
int id=Integer.decode(req.getParameter("id"));
String username=req.getParameter("username");
String password=req.getParameter("password");
User user=new User();
user.setId(id);
user.setUsername(username);
user.setPassword(password);
UserService u=new UserService();
int num=u.getUpdate(user);
if(num>0){
req.getRequestDispatcher("LoginServlet").forward(req,resp);
}else{
req.getRequestDispatcher("update.jsp").forward(req,resp);
}
}
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
doPost(req, resp);
}
}
5.DeleteServlet.java
package servlet;
import service.UserService;
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 java.io.IOException;
@WebServlet("/DeleteServlet")
public class DeleteServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
doPost(req, resp);
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
int id=Integer.decode(req.getParameter("id"));
UserService u=new UserService();
int num=u.getDelete(id);
req.getRequestDispatcher("UserServlet").forward(req,resp);
}
}
（6）webapp
1.index.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<h2>登入</h2><a href="register.jsp">註冊</a>
<form action="LoginServlet" method="post">
使用者名稱：<input type="text" name="username">
密碼：<input type="text" name="password">
<input type="submit" value="確定"/>
</form>
</body>
</html>
2.register.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<h2>註冊</h2><a href="index.jsp"></a>
<form action="RegisterServlet" method="post">
使用者名稱：<input type="text" name="username">
密碼： <input type="text" name="password">
<input type="submit" >
</form>
</body>
</html>
3.success.jsp
<%@ page import="entity.User" %>
<%@ page import="java.util.List" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<table>
<tr>
<td>id</td>
<td>使用者名稱</td>
<td>密碼</td>
<td>修改</td>
<td>刪除</td>
</tr>
<%
List<User> us=(List<User>)request.getAttribute("User");
for(User u:us){%>
<tr>
<td><%=u.getId()%></td>
<td><%=u.getUsername()%></td>
<td><%=u.getPassword()%></td>
<td><a href="update.jsp?id=<%=u.getId()%>&&username=<%=u.getUsername()%>&&password=<%=u.getPassword()%>">修改</a></td>
<td><a href="DeleteServlet?id=<%=u.getId()%>">刪除</a> </td>
</tr>
<%}%>
</table>
</body>
</html>
4.error.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
賬戶名或密碼錯誤！
</body>
</html>
5.update.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<form action="UpdateServlet" method="post">
<table>
<tr>
<td>id</td>
<td><input type="text" name="id" value="<%=request.getParameter("id")%>"></td>
</tr>
<tr>
<td>使用者名稱</td>
<td><input type="text" name="username" value="<%=request.getParameter("username")%>"></td>
</tr>
<tr>
<td>密碼</td>
<td><input type="text" name="password" value="<%=request.getParameter("password")%>"></td>
</tr>
</table>
<input type="submit">
</form>
</body>
</html>
（7）pom.xml
<!-- https://mvnrepository.com/artifact/javax.servlet/javax.servlet-api --> <dependency> <groupId>javax.servlet</groupId> <artifactId>javax.servlet-api</artifactId> <version>3.1.0</version> <scope>provided</scope> </dependency> <!-- https://mvnrepository.com/artifact/org.springframework/spring-jdbc --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-jdbc</artifactId> <version>5.1.5.RELEASE</version> </dependency> <!-- https://mvnrepository.com/artifact/com.mchange/c3p0 --> <dependency> <groupId>com.mchange</groupId> <artifactId>c3p0</artifactId> <version>0.9.5.2</version> </dependency> <!-- https://mvnrepository.com/artifact/org.apache.tomcat/tomcat-jdbc --> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.25</version> </dependency>
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