Mybatis-使用代码建立连接

ゝ一纸荒年。 2022-03-01 06:58 159阅读 0赞

主类：MyBatisDemo

public class MyBatisDemo {
        public static void main(String[] args) {
            // 配置数据源
            PooledDataSource dataSource = new PooledDataSource();
            dataSource.setDriver("com.mysql.cj.jdbc.Driver");
            dataSource.setUrl("jdbc:mysql://127.0.0.1:3306/rogueq?serverTimezone=UTC");
            dataSource.setUsername("root");
            dataSource.setPassword("root");
    
            // 创建事务处理器
            TransactionFactory transactionFactory = new JdbcTransactionFactory();
    
            // 创建环境对象 并命名为 development
            Environment environment =
                    new Environment("development", transactionFactory, dataSource);
    
            // 构建Configuration对象
            Configuration configuration = new Configuration(environment);
    
            // 注册一个mybatis上下文别名
            configuration.getTypeAliasRegistry().registerAlias("user", User.class);
    
            // 加入一个映射器
            configuration.addMapper(UserMapper.class);
    
            // 使用SqlSessionFactoryBuilder构建SqlSessionFactory
            SqlSessionFactory sqlSessionFactory =
                    new SqlSessionFactoryBuilder().build(configuration);
    
            // 使用SqlSessionFactory创建会话
            SqlSession sqlSession = sqlSessionFactory.openSession();
    
            UserMapper mapper = sqlSession.getMapper(UserMapper.class);
    
            User user = mapper.selectById(10000L);
    
            System.out.println(user);
        }
    }

Mapper接口： UserMapper

import org.apache.ibatis.annotations.Param;
    
    public interface UserMapper {
    
        User selectById(@Param("id") Long id);
    
    }

映射文件： UserMapper.xml

<?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="cn.rogueq.mybatis.UserMapper">
        <select id="selectById" resultType="user">
            select * from user where id = #{id}
        </select>
    </mapper>

实体类：

package cn.rogueq.entity;
    
    import java.util.Date;
    
    public class User {
        private Long id;
        private String username;
        private String nickname;
        private String password;
        private String phone;
        private String email;
        private String identity;
        private Date createTime;
        private Date updateTime;
    
        public Long getId() {
            return id;
        }
    
        public void setId(Long id) {
            this.id = id;
        }
    
        public String getUsername() {
            return username;
        }
    
        public void setUsername(String username) {
            this.username = username;
        }
    
        public String getNickname() {
            return nickname;
        }
    
        public void setNickname(String nickname) {
            this.nickname = nickname;
        }
    
        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 getEmail() {
            return email;
        }
    
        public void setEmail(String email) {
            this.email = email;
        }
    
        public String getIdentity() {
            return identity;
        }
    
        public void setIdentity(String identity) {
            this.identity = identity;
        }
    
        public Date getCreateTime() {
            return createTime;
        }
    
        public void setCreateTime(Date createTime) {
            this.createTime = createTime;
        }
    
        public Date getUpdateTime() {
            return updateTime;
        }
    
        public void setUpdateTime(Date updateTime) {
            this.updateTime = updateTime;
        }
    
        @Override
        public String toString() {
            return "User{" +
                    "id=" + id +
                    ", username='" + username + '\'' +
                    ", phone='" + phone + '\'' +
                    '}';
        }
    }

执行结果：

User\{id=10000, username='admin', phone='null'\}