mybatis+servlet实现用户注册与登录
环境准备
- 创建注册页面与登录页面
login.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>login</title>
</head>
<body>
<form action="/tomcat_war/loginServlet" method="post">
<h1 id="loginMsg">Login In</h1>
<p>username:<input id="username" name="username" type="text"></p>
<p>password:<input id="password" name="password" type="password"></p>
<input type="submit" class="button" value="login up">
<input type="reset" class="button" value="reset">
<a href="register.html">没有账号?点击注册</a>
</form>
</body>
</html>
register.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>register</title>
</head>
<body>
<form action="/tomcat_war/registerServlet" method="get">
<h1>Login In</h1>
<p>username:<input id="username" name="username" type="text"></p>
<p>password:<input id="password" name="password" type="password"></p>
<input type="submit" class="button" value="register">
<input type="reset" class="button" value="reset">
<a href="login.html">已有账号,跳转到登录</a>
</form>
</body>
</html>
- 在数据库中创建表与数据(数据库名为db)
create table tb_user (
id int primary key auto_increment,
username varchar(20) unique,
password varchar(32)
);
insert into tb_user(username, password) values('zhangsan', '123'), ('lisi', '234');
select * from tb_user;
- 创建POJO类User.java(在pojo目录下)
package org.example.pojo;
public class User {
private Integer id;
private String username;
private String 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 + '\'' +
'}';
}
}
- pom.xml导入MyBatis坐标和MySQL驱动坐标
<!-- https://mvnrepository.com/artifact/org.mybatis/mybatis -->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.5.10</version>
</dependency>
<!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.30</version>
</dependency>
- 创建mybatis-config.xml(resource目录下)
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<typeAliases>
<typeAlias type="org.example.pojo.User" alias="Brand"/>
</typeAliases>
<environments default="development">
<environment id="development">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="com.mysql.cj.jdbc.Driver"/>
<property name="url" value="jdbc:mysql:///db?useSSL=false&useServerPrepStmts=true"/>
<property name="username" value="root"/>
<property name="password" value="lbyuoe"/>
</dataSource>
</environment>
</environments>
<mappers>
<package name="org.example.mapper"/>
</mappers>
</configuration>
- 创建UserMapper.java接口(org.example.mapper目录下)
- 创建UserMapper.xml(resource.org.example.mapper目录下)
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="org.example.mapper.UserMapper">
</mapper>
用户登录
- UserMapper.java编写查询代码
/**
* 根据用户名和密码查找对象
* @param username
* @param password
* @return
*/
@Select("select * from tb_user where username = #{username} and password = #{password}")
User select(@Param("username")String username, @Param("password")String password);
- 创建LoginServlet.java(在org.example.web目录下)
package org.example.web;
import jakarta.servlet.*;
import jakarta.servlet.http.*;
import jakarta.servlet.annotation.*;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.example.mapper.UserMapper;
import org.example.pojo.User;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
@WebServlet("/loginServlet")
public class LoginServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// 接受用户名和密码
String username = request.getParameter("username");
String password = request.getParameter("password");
// 调用MyBatis完成查询
// 获取SqlSessionFactory对象
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
// 获取SqlSession对象
SqlSession sqlSession = sqlSessionFactory.openSession();
// 获取Mapper
UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
// 调用方法
User user = userMapper.select(username, password);
// 释放资源
sqlSession.close();
// 判断User查询结果
response.setContentType("text/html");
PrintWriter writer = response.getWriter();
if (user != null) {
// 登录成功
writer.write("登录成功");
} else {
// 登录失败
writer.write("登录失败");
}
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doGet(request, response);
}
}
# 用户注册 1. UserMapper.java添加用户名查找和添加用户名密码的代码 ```java /** * 根据用户名查找对象 * @param username * @return */ @Select("select * from tb_user where username = #{username}") User selectByUsername(@Param("username")String username);
/**
* 添加用户名和密码
* @param user
*/
@Insert("insert into tb_user (id, username, password) values (null, #{username}, #{password});")
void add(User user);
2. 编写LoginServlet代码(org.example.web目录下)
```java
package org.example.web;
import jakarta.servlet.*;
import jakarta.servlet.http.*;
import jakarta.servlet.annotation.*;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.example.mapper.UserMapper;
import org.example.pojo.User;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
@WebServlet("/registerServlet")
public class RegisterServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// 接收用户输入的数据
String username = request.getParameter("username");
String password = request.getParameter("password");
// 封装用户对象
User user = new User();
user.setUsername(username);
user.setPassword(password);
// 调用MyBatis完成查询
// 获取SqlSessionFactory对象
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
// 获取SqlSession对象
SqlSession sqlSession = sqlSessionFactory.openSession();
// 获取Mapper
UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
// 获取字节输出流
response.setContentType("text/html");
PrintWriter writer = response.getWriter();
// 查询用户名是否存在
if (userMapper.selectByUsername(username) != null) {
// 用户名已存在
writer.write("用户名已存在");
} else {
// 不用户名不存在,添加数据
userMapper.add(user);
// 提交事务
sqlSession.commit();
}
// 释放资源
sqlSession.close();
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doGet(request, response);
}
}
最后结果
github:https://github.com/ciyeye/mybatis_servlet_for_login_register
来源:https://www.bilibili.com/video/BV1Qf4y1T7Hx(P109、P110)