一，完成数据库编写
DROP DATABASE if EXISTS mydb;
CREATE DATABASE mydb;
use mydb;
CREATE TABLE ta_user
(
uid int primary key auto_increment,
username varchar(32),
password varchar(32),
phone varchar(32),
address varchar(32)
);
INSERT INTO ta_user(username,password,phone,address)VALUES('张三','123','12323231','北京');
INSERT INTO ta_user(username,password,phone,address)VALUES('李四','456','35343434','上海');
INSERT INTO ta_user(username,password,phone,address)VALUES('王五','789','33234324','河南');
SELECT * from ta_user;
二，网页前端显示部分（HTML部分）
注：注意文件创建地方
分层思想：创建一些包将一大堆代码分散到各个包中，可以使代码简洁，容易后期维护
<%--
Created by IntelliJ IDEA.
User: ThinkPad
Date: 2023/2/18
Time: 8:35
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>首页</title>
</head>
<body>
<a href="login.jsp">去登陆</a>
</body>
</html>
登录页面<%--
Created by IntelliJ IDEA.
User: ThinkPad
Date: 2023/2/18
Time: 8:37
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>登录页面</title>
</head>
<body>
<%--有jsp不经过数据，没有jsp经过--%>
<form action="login" method="post">
账号：<input type="text" name="username"><br>
密码：<input type="password" name="password"><br>
<input type="submit" value="登录"><br>
<a href="register.jsp">没有账号？前往注册</a>
<a href="index.jsp">返回首页</a>
</form>
</body>
</html>
注册页面<%--
Created by IntelliJ IDEA.
User: ThinkPad
Date: 2023/2/18
Time: 12:27
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>注册</title>
</head>
<body>
<form action="register" method="post">
账号：<input type="text" name="username"><br>
密码：<input type="password" name="password"><br>
号码：<input type="password" name="phone"><br>
地址：<input type="password" name="address"><br>
<input type="submit" value="注册"><br>
<a href="login.jsp">有账号？前往登录</a>
<a href="index.jsp">返回首页</a>
</form>
</body>
</html>
错误页面<%--
Created by IntelliJ IDEA.
User: ThinkPad
Date: 2023/2/18
Time: 9:50
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<a>错误</a>
<a href="index.jsp">返回登录页面</a>
</body>
</html>
登陆成功后跳转页面<%--
Created by IntelliJ IDEA.
User: ThinkPad
Date: 2023/2/18
Time: 9:30
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>商品</title>
</head>
<body>
<form>
<tr>
<td>苹果</td>
<td>2</td>
</tr>
<tr>
<td>橘子</td>
<td>6</td>
</tr>
<tr>
<td>香蕉</td>
<td>5</td>
</tr>
</form>
</body>
</html>
三，后端控制部分（Java部分）
bean包用来放属性的构造方法
package com.smrsar.bean;
public class User {
private Integer uid;
private String username;
private String password;
private String phone;
private String address;
public User() {
}
@Override
public String toString() {
return "User{" +
"uid=" + uid +
", username='" + username + ''' +
", password='" + password + ''' +
", phone='" + phone + ''' +
", address='" + address + ''' +
'}';
}
public Integer getUid() {
return uid;
}
public void setUid(Integer uid) {
this.uid = uid;
}
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;
}
public String getPhone() {
return phone;
}
public void setPhone(String phone) {
this.phone = phone;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
public User(Integer uid, String username, String password, String phone, String address) {
this.uid = uid;
this.username = username;
this.password = password;
this.phone = phone;
this.address = address;
}
}
package com.smrsar.bean;
public class Userz {
private Integer uid;
private String username;
private String password;
public Userz() {
}
@Override
public String toString() {
return "Userz{" +
"uid=" + uid +
", username='" + username + ''' +
", password='" + password + ''' +
'}';
}
public Integer getUid() {
return uid;
}
public void setUid(Integer uid) {
this.uid = uid;
}
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;
}
public Userz(Integer uid, String username, String password) {
this.uid = uid;
this.username = username;
this.password = password;
}
}
dao包用来放Java代码（注册部分的JDBC代码，分层方法：构建成一个方法，在Servlet中直接调用）
package com.smrsar.dao;
import com.smrsar.bean.User;
import com.smrsar.util.JDBCUtil;
import java.sql.Connection;
import java.sql.PreparedStatement;
public class UserDaoImpl {
public int register (User user){
Connection con = null;
PreparedStatement pstm = null;
int row = 0;
try {
con=JDBCUtil.GetCon();
String sql = "insert into ta_user(username,password,phone,address)values (?,?,?,?)";
pstm = con.prepareStatement(sql);
pstm.setObject(1, user.getUsername());
pstm.setObject(2, user.getPassword());
pstm.setObject(3, user.getPhone());
pstm.setObject(4, user.getAddress());
row = pstm.executeUpdate();
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
if (pstm != null) {
pstm.close();
}
if (con != null) {
con.close();
}
} catch (Exception e) {
e.printStackTrace();
}
}
return row;
}
}
JDBC工具类构造方法用来调用
package com.smrsar.util;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
public class JDBCUtil {
private static String driver = "com.mysql.cj.jdbc.Driver";
private static String url = "jdbc:mysql://localhost:3306/mydb?useSSL=false&serverTimezone=UTC";
private static String username = "root";
private static String password = "root";
public static Connection con = null;
public static Connection GetCon() {
try {
Class.forName(driver);
con = DriverManager.getConnection(url, username, password);
} catch (Exception e) {
e.printStackTrace();
}
return con;
}
public static void Close(ResultSet rs, PreparedStatement pstm, Connection con) {
try {
if (rs != null) {
rs.close();
}
if (pstm != null) {
pstm.close();
}
if (con != null) {
con.close();
}
} catch (Exception e) {
e.printStackTrace();
}
}
}
登录和注册servlet部分代码
package com.smrsar.servlet;
import com.smrsar.bean.Userz;
import com.smrsar.util.JDBCUtil;
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.sql.*;
@WebServlet("/login")
public class Login 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");
resp.setCharacterEncoding("utf-8");
resp.setContentType("ext/html;charset=UTF-8");
String username = req.getParameter("username");
String password = req.getParameter("password");
Connection con = null;
PreparedStatement pstm = null;
ResultSet rs = null;
Userz login = null;
try {
con = JDBCUtil.GetCon();
String sql = "select * from ta_user where username=? and password=?";
pstm = con.prepareStatement(sql);
pstm.setObject(1, username);
pstm.setObject(2, password);
rs = pstm.executeQuery();
if (rs.next()) {
login = new Userz();
login.setUid(rs.getInt("uid"));
login.setUsername(rs.getString("username"));
login.setPassword(rs.getString("password"));
}
} catch (Exception e) {
e.printStackTrace();
} finally {
JDBCUtil.Close(rs, pstm, con);
}
if (login != null) {
resp.sendRedirect("goods.jsp");
} else {
resp.sendRedirect("error.jsp");
}
}
}
package com.smrsar.servlet;
import com.smrsar.bean.User;
import com.smrsar.dao.UserDaoImpl;
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("/register")
public class Register 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");
resp.setCharacterEncoding("utf-8");
resp.setContentType("ext/html;charset=UTF-8");
String username = req.getParameter("username");
String password = req.getParameter("password");
String phone = req.getParameter("phone");
String address = req.getParameter("address");
User user = new User();
user.setUsername(username);
user.setPassword(password);
user.setPhone(phone);
user.setAddress(address);
System.out.println(user);
UserDaoImpl userDao=new UserDaoImpl();
int row=userDao.register(user);
if (row > 0) {
resp.sendRedirect("login.jsp");
} else {
resp.sendRedirect("register.jsp");
}
}
}
