MyBatis核心配置文件及映射文件详解

<?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>

    <!--定义属性文件
        resource：从类路径下面读取外部文件
        url：从一个资源定位地址来读取配置文件
        提供参数使用: 可以使用 ${参数名} 进行参数引用
    -->
  <environments default="default">
        <!--环境变量-->
        <environment id="default">
            <!--事务管理器：由JDBC管理事务 -->
            <transactionManager type="JDBC"/>
            <!--数据源配置信息：POOLED 使用连接池 -->
            <dataSource type="POOLED">
                <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="2022"/>
            </dataSource>
        </environment>
    </environments>

    <!-- 加载其他的映射文件 -->
    <mappers>
        <mapper resource="org/mybatis/example/BlogMapper.xml"/>
    </mappers>
</configuration>

@Test
public void testMyBatis() throws IOException {
    //加载核心配置文件
    InputStream is = Resources.getResourceAsStream("mybatis-config.xml");
    //获取SqlSessionFactoryBuilder
    SqlSessionFactoryBuilder sqlSessionFactoryBuilder = new SqlSessionFactoryBuilder();
    //获取SqlSessionFactory
    SqlSessionFactory sqlSessionFactory = sqlSessionFactoryBuilder.build(is);
    //获取SqlSession
    SqlSession sqlSession = sqlSessionFactory.openSession();
    //获取mapper接口对象
    UserMapper mapper = sqlSession.getMapper(UserMapper.class);
    //测试功能
    int result = mapper.insertUser();
    //提交事务
    sqlSession.commit();
    System.out.println("result:"+result);
}

<!--log4j日志-->
<dependency>
    <groupId>log4j</groupId>
    <artifactId>log4j</artifactId>
    <version>1.2.17</version>
</dependency>

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">
<log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/">
    <appender name="STDOUT" class="org.apache.log4j.ConsoleAppender">
        <param name="Encoding" value="UTF-8"/>
        <layout class="org.apache.log4j.PatternLayout">
            <param name="ConversionPattern" value="%-5p %d{MM-dd HH:mm:ss,SSS}
%m (%F:%L) \n"/>
        </layout>
    </appender>
    <logger name="java.sql">
        <level value="debug"/>
    </logger>
    <logger name="org.apache.ibatis">
        <level value="info"/>
    </logger>
    <root>
        <level value="debug"/>
        <appender-ref ref="STDOUT"/>
    </root>
</log4j:configuration>