Mybatis入门

<packaging>jar</packaging>

    <dependencies>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.4.5</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.6</version>
        </dependency>
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.12</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.10</version>
        </dependency>
    </dependencies>

<?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">
<!--mybatis的主配置文件-->
<configuration>
    <!--配置环境-->
    <environments default="mysql">
        <!--配置Mysql的环境，id和default必须相同-->
        <environment id="mysql">
            <!--配置事务类型-->
            <transactionManager type="JDBC"></transactionManager>
            <!--配置数据源（也叫连接池）-->
            <dataSource type="POOLED">
                <!--配置连接数据库的4个基本信息-->
                <property name="driver" value="com.mysql.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/mybatis_study?characterEncoding=UTF-8"/>
                <property name="username" value="root"/>
                <property name="password" value="2013.71123"/>
            </dataSource>
        </environment>

    </environments>
    <!--配置映射文件目录：xml方式-->
    <mappers>
        <mapper resource="com/itheima/dao/IUserMapper.xml"></mapper>
    </mappers>
    <!--配置映射文件目录：注解方式  全限定类名
        使用注解方式就不需要IUserMapper.xml配置文件了
    -->
    <!--<mappers>-->
        <!--<mapper class="com.itheima.dao.IUserDao"></mapper>-->
    <!--</mappers>-->
</configuration>

<?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">
<!-- namespace必须定义，代表此Mapper是哪个接口的映射文件 -->
<mapper namespace="com.itheima.dao.IUserDao">
    <!--id为接口中的方法名-->
    <select id="findAll" resultType="com.itheima.domain.User">
        select * from user;
    </select>   
</mapper>

@Test
public void TestFindAll() throws IOException {
    //1.读取配置文件
    InputStream in = Resources.getResourceAsStream("SqlMapConfig.xml");
    
    //2.创建SqlSessionFactory
    SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(in);
    
    //3.使用工厂创建SqlSession对象
    SqlSession session = sessionFactory.openSession();
    
    //4.使用SqlSession对象创建Dao接口的代理对象
    IUserDao userDao = session.getMapper(IUserDao.class);
    
    //5.使用代理对象执行方法
    List<User> all = userDao.findAll();
    for (User user:all) {
        System.out.println(user);
    }
    
    //6.释放资源
    in.close();
    session.close();
}

### direct log messages to stdout ###
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target=System.out
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{ABSOLUTE} %5p %c{1}:%L - %m%n

### direct messages to file mylog.log ###
log4j.appender.file=org.apache.log4j.FileAppender
log4j.appender.file.File=c\:mylog.log
log4j.appender.file.layout=org.apache.log4j.PatternLayout
log4j.appender.file.layout.ConversionPattern=%d{ABSOLUTE} %5p %c{1}:%L - %m%n

### set log levels - for more verbose logging change ‘info‘ to ‘debug‘ ###
# error warn info debug trace
log4j.rootLogger= debug,stdout