1.pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>org.example</groupId>
<artifactId>mybits-demo</artifactId>
<version>1.0-SNAPSHOT</version>
<dependencies>
<!-- mybatis 的依赖-->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.5.5</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.46</version>
</dependency>
<dependency>
<!-- 单元测试的-->
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.13.1</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>1.7.30</version>
</dependency>
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-classic</artifactId>
<version>1.2.3</version>
</dependency>
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-core</artifactId>
<version>1.2.3</version>
</dependency>
</dependencies>
</project>
2.
<?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">
<!-- 根标签里面有
namespace:名称空间
resultType:返回结果的类型,一般来说是我自己定义的类。
select 中的id 是唯一标识,不能够重复。
-->
<mapper namespace="test">
<select id="selectAll" resultType="com.itheima.pojo.User">
select * from tb_user;
</select>
</mapper>
3.
<?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>
<environments default="development">
<environment id="development">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<!--数据库的连接信息-->
<!-- <property name="driver" value="${driver}"/>-->
<!-- <property name="url" value="${url}"/>-->
<!-- <property name="username" value="${username}"/>-->
<!-- <property name="password" value="${password}"/>-->
<property name="driver" value="com.mysql.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://localhost:3306/mybatis"/>
<property name="username" value="root"/>
<property name="password" value="wgs"/>
</dataSource>
</environment>
</environments>
<mappers>
<!-- 这个是sql映射文件的路径的。也是需要更改的-->
<mapper resource="UserMapper.xml"/>
</mappers>
</configuration>
4.logback
<?xml version="1.0" encoding="UTF-8"?>
<configuration>
<!--
CONSOLE :表示当前的日志信息是可以输出到控制台的。
-->
<appender name="Console" class="ch.qos.logback.core.ConsoleAppender">
<encoder>
<pattern>[%level] %blue(%d{HH:mm:ss.SSS}) %cyan([%thread]) %boldGreen(%logger{15}) - %msg %n</pattern>
</encoder>
</appender>
<logger name="com.itheima" level="DEBUG" additivity="false">
<appender-ref ref="Console"/>
</logger>
<root level="DEBUG">
<appender-ref ref="Console"/>
</root>
</configuration>
5.
package com.itheima;
import com.itheima.pojo.User;
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;
import java.util.List;
/**
* mybatis 快速入门代码
*/
public class MybatisDemo {
public static void main(String[] args) throws IOException {
//1.加载Mybatis 的核心配置文件,获取 sqlSessionFactory,用来执行sql语句的。
String resource = "mybatis-config.xml";//配置文件的路径,就是加载url 用户名和密码之类的。
InputStream inputStream = Resources.getResourceAsStream(resource);
//通过mybatis 提供的一个资源加载的类 Resources类 ,将字符串输入的进来,得到一个字节输入流。
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//然后得到一个sqlSessionFactory 对象。
/**
* 2.获取sqlSession 对象 ,用来执行sql 语句
*/
SqlSession sqlSession = sqlSessionFactory.openSession();
/**
* 3.执行sql 语句
*
* test.selectAll :是 namespace.id
*/
List<User> users = sqlSession.selectList("test.selectAll");
System.out.println(users);
/**
* 4.释放资源
*/
sqlSession.close();
}
}