第一个Mybatis项目

1.mybatis-config.xml 配置及pom文件

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "https://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/mybatis?useSSL=false&amp;useUnicode=true&amp;characterEncoding=utf8&amp;zeroDateTimeBehavior=convertToNull&amp;serverTimezone=GMT%2B8"/>
                <property name="username" value="root"/>
                <property name="password" value="123456"/>
            </dataSource>
        </environment>
    </environments>
    <mappers>
     <mapper resource="com/kuang/mapper/UserMapper.xml"/>
    </mappers>
</configuration>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.47</version>
        </dependency>
        
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.13</version>
        </dependency>

2. dao

public interface UserDao {
​
    List<User> getUserList();
}

3. mapper

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "https://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.kuang.dao.UserDao">
    <select id="getUserList" resultType="com.kuang.pojo.User">
        select * from mybatis.user
    </select>
</mapper>
​

4.pojo类

package com.kuang.pojo;
​
import java.io.Serializable;
import java.util.Date;
​
/**
 * @Author 77
 * @Description
 * @Date
 **/
public class User implements Serializable {
​
    private int id;
    private String username;
    private String pwd;
    private Date birthday;
​
    public User() {
    }
​
    public User(int id, String username, String pwd, Date birthday) {
        this.id = id;
        this.username = username;
        this.pwd = pwd;
        this.birthday = birthday;
    }
​
    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 getPwd() {
        return pwd;
    }
​
    public void setPwd(String pwd) {
        this.pwd = pwd;
    }
​
    public Date getBirthday() {
        return birthday;
    }
​
    public void setBirthday(Date birthday) {
        this.birthday = birthday;
    }
​
    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", username='" + username + '\'' +
                ", pwd='" + pwd + '\'' +
                ", birthday=" + birthday +
                '}';
    }
}
​

5. 创建公共类 获取SqlSession

package com.kuang.utils;
​
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 java.io.IOException;
import java.io.InputStream;
public class MybatisUtils {
​
    private static SqlSessionFactory sqlSessionFactory;
​
   static {
       try {
           String resource = "mybatis-config.xml";
           InputStream inputStream = Resources.getResourceAsStream(resource);
           sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
       } catch (IOException e) {
           e.printStackTrace();
       }
   }
​
   public static SqlSession getSqlSession(){
        return sqlSessionFactory.openSession();
   }
​
}
​

6. 测试类及测试结果

package com.kuang;
​
import com.kuang.dao.UserDao;
import com.kuang.pojo.User;
import com.kuang.utils.MybatisUtils;
import org.apache.ibatis.session.SqlSession;
import org.junit.Test;
​
import java.util.List;
​
public class UserDaoTest {
​
    @Test
    public void test(){
        //获取sqlSession 对象
        SqlSession sqlSession = MybatisUtils.getSqlSession();
​
        UserDao userDao = sqlSession.getMapper(UserDao.class);
        List<User> userList = userDao.getUserList();
​
        for (User user : userList) {
            System.out.println(user);
        }
        sqlSession.close();
    }
}

User{id=1, username='狂神', pwd='e10adc3949ba59abbe56e057f20f883e', birthday=Sun Oct 08 00:00:00 CST 2023}
User{id=2, username='烈儿', pwd='e10adc3949ba59abbe56e057f20f883e', birthday=Sat Oct 07 00:00:00 CST 2023}
User{id=3, username='孙霸', pwd='e10adc3949ba59abbe56e057f20f883e', birthday=Fri Oct 06 00:00:00 CST 2023}
​
Process finished with exit code 0