JavaWeb 第三章 Servlet+JDBC实现登录注册
Servlet+jdbc实现登录注册
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- 一、步骤
- 二、封装连接数据库的工具类
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- JDBCUtils
- config.properties
- 引入数据库的工具类
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- 三、注册
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- register.jsp
- User
- BaseDao 接口
- UserDao.java
- RegisterServlet.java
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- 四、登录
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- login.jsp
- LoginServlet.java
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一、步骤
- 准备数据库 javaweb2305或者javaweb2306
- 创建数据库表 student
- 创建三层架构模块
二、封装连接数据库的工具类
JDBCUtils
package cn.tedu.utils;
import java.io.IOException;
import java.io.InputStream;
import java.sql.*;
import java.util.Properties;
public class JDBCUtils {
public JDBCUtils(){}
private static String driverClass;
private static String url;
private static String username;
private static String passward;
private static Connection con;
static {
try {
InputStream is = JDBCUtils.class.getClassLoader().getResourceAsStream("config.properties");
Properties prop = new Properties();
prop.load(is);
driverClass = prop.getProperty("driverClass");
url = prop.getProperty("url");
username = prop.getProperty("username");
passward = prop.getProperty("password");
Class.forName(driverClass);
} catch (IOException e) {
e.printStackTrace();
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
}
public static Connection getConnection(){
try {
con = DriverManager.getConnection(url,username,passward);
} catch (SQLException e) {
e.printStackTrace();
}
return con;
}
public static void close(Connection con, Statement sta, ResultSet rs){
if (con != null){
try {
con.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if (sta != null){
try {
sta.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if (rs != null){
try {
rs.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
public static void close(Connection con, Statement sta){
if (con != null){
try {
con.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if (sta != null){
try {
sta.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
}
config.properties
driverClass = com.mysql.cj.jdbc.Driver
url = jdbc:mysql://localhost:3306/javaweb
username = root
password = root
引入数据库的工具类
三、注册
register.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>注册页面</title>
</head>
<body>
<div style="text-align: center">
<form action="RegisterServlet" method="post" id="registerform">
账号：<input type="text" placeholder="手机号或邮箱" name="username"/><br>
密码：<input type="password" placeholder="密码" name="password"/><br>
<input type="submit" class="inputButton" value="注册" />
</form>
</div>
</body>
</html>
User
package cn.tedu.bean;
public class User {
private Integer id;
private String username;
private String password;
public User(Integer o, String username, String password) {
this.id=o;
this.username=username;
this.password=password;
}
public Integer getId() {
return id;
}
public void setId(Integer 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 + '\'' +
'}';
}
}
BaseDao 接口
package cn.tedu.dao;
import java.util.List;
public interface BaseDao<E> {
public boolean add(E e);
public void delete(E e);
public void update(E e);
public boolean findbone(String username, String passward);
public List<E> findall();
}
UserDao.java
package cn.tedu.dao;
import cn.tedu.bean.User;
import cn.tedu.utils.JDBCUtils;
import java.sql.*;
import java.util.ArrayList;
import java.util.List;
public class UserDao implements BaseDao<User>{
JDBCUtils jdb = new JDBCUtils();
@Override
public boolean add(User user) {
Connection con = null;
PreparedStatement stat = null;
int i = 0;
try{
con = JDBCUtils.getConnection();
stat = con.prepareStatement("INSERT INTO student VALUES(?,?,?)");
System.out.println(user.getUsername());
System.out.println(user.getPassword());
stat.setString(1,null);
stat.setString(2, user.getUsername());
stat.setString(3, user.getPassword());
i = stat.executeUpdate();
System.out.println(i);
}catch (Exception e){
e.printStackTrace();
}finally {
JDBCUtils.close(con, stat);
}
if(i>0){
return true;
}else {
return false;
}
}
@Override
public void delete(User user) {
Connection con = null;
Statement stat = null;
try{
con = JDBCUtils.getConnection();
stat = con.createStatement();
String sql = "DELETE FROM user WHERE id='"+user.getId()+"'";
stat.executeUpdate(sql);
}catch (Exception e){
e.printStackTrace();
}finally {
JDBCUtils.close(con, stat);
}
}
@Override
public void update(User o) {
}
@Override
public boolean findbone(String username, String password) {
Connection con = null;
PreparedStatement stat = null;
ResultSet rs = null;
boolean result = false;
try {
con = JDBCUtils.getConnection();
stat = con.prepareStatement("SELECT *FROM student WHERE username = ? and password = ?");
stat.setString(1, username);
stat.setString(2, password);
rs = stat.executeQuery();
if (rs.next()) {
result = true;
} else {
result = false;
}
} catch (Exception e) {
e.printStackTrace();
} finally {
JDBCUtils.close(con, stat, rs);
}
return result;
}
@Override
public List findall() {
Connection con = null;
Statement stat = null;
ResultSet rs = null;
ArrayList<User> list = new ArrayList<User>();
try{
con = JDBCUtils.getConnection();
stat = con.createStatement();
String sql = "SELECT *FROM student";
rs = stat.executeQuery(sql);
while(rs.next()){
int id = rs.getInt("id");
String name = rs.getString("name");
User user = new User(id, name,null);
list.add(user);
}
}catch (Exception e){
e.printStackTrace();
}finally {
JDBCUtils.close(con, stat, rs);
}
return list;
}
}
RegisterServlet.java
package cn.tedu.servlet;
import cn.tedu.bean.User;
import cn.tedu.dao.UserDao;
import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
import java.io.IOException;
@WebServlet(name = "RegisterServlet", value = "/RegisterServlet")
public class RegisterServlet extends HttpServlet {
UserDao userDao = new UserDao();
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doPost(request,response);
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String username = request.getParameter("username");
String password = request.getParameter("password");
System.out.println(username);
System.out.println(password);
User user = new User(null,username,password);
System.out.println(user);
System.out.println(user.getUsername());
System.out.println(user.getPassword());
if(userDao.add(user)){
response.sendRedirect(request.getContextPath()+"/success.jsp");
System.out.println("用户注册成功");
}else{
response.sendRedirect(request.getContextPath()+"/error.jsp");
System.out.println("用户注册失败");
}
}
}
四、登录
login.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>登录</title>
</head>
<body>
<%--<link rel="stylesheet" type="text/css" href="./homepage.css">--%>
<div style="text-align: center">
<form action="LoginServlet" method="post" id="loginform">
账号：<input type="text" placeholder="手机号或邮箱" name="username"/><br>
密码：<input type="password" placeholder="密码" name="password"/><br>
<input type="submit" class="inputButton" value="登录" />
<a href="register.jsp">没有账号，点击注册</a>
</form>
</div>
</body>
</html>
LoginServlet.java
package cn.tedu.servlet;
import cn.tedu.dao.UserDao;
import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
import java.io.IOException;
@WebServlet(name = "LoginServlet", value = "/LoginServlet")
public class LoginServlet extends HttpServlet {
UserDao userDao = new UserDao();
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doPost(request,response);
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String username = request.getParameter("username");
String password = request.getParameter("password");
System.out.println(password);
System.out.println(username);
if(userDao.findbone(username,password)){
response.sendRedirect(request.getContextPath()+"/success.jsp");
}else{
response.sendRedirect(request.getContextPath()+"/error.jsp");
}
}
}