1、mybatis学习——mybatis入门程序

一、原始方式：

　　1.创建employee表

　　

　　2.项目中创建相对应的bean

　　3.导入基本jar包

 　　4.将日志文件配置导入

# Global logging configuration
#在开发环境下日志级别要设置成DEBUG，生产环境设置成ERROR或者INFO
log4j.rootLogger=DEBUG, stdout
# MyBatis logging configuration...
log4j.logger.org.mybatis.example.BlogMapper=TRACE
# Console output...
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%5p [%t] - %m%n

　　5.创建数据源文件

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/mybatisstudy
jdbc.username=root
jdbc.password=123

　　6.创建mybatis全局配置文件

<?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>
		<!-- resource:引入类路径下的资源
			url:引入网络路径或者磁盘路径下的资源 -->
	  <properties resource="dbconfig.properties"></properties>
	
	 <environments default="development">
		 <environment id="development">
			 <transactionManager type="JDBC"/>
				 <dataSource type="POOLED">
					 <property name="driver" value="${jdbc.driver}"/>
					 <property name="url" value="${jdbc.url}"/>
					 <property name="username" value="${jdbc.username}"/>
					 <property name="password" value="${jdbc.password}"/>
			 	 </dataSource>
		 </environment>
	 </environments>
	 
　　　　</configuration>

　　7.创建employee的sql映射文件

<?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="com.pxxy.bean.mapper.EmployeeMapper">
	<select id="selectEmpById" resultType="com.pxxy.bean.Employee">
		select * from employee where id = #{id}
	</select>
</mapper>

　　8.在mybatis的全局配置文件中添加映射

 　　9.创建测试类

public class MybatisTest1 {
	
	/**
	 * 1.根据xml配置文件（全局配置文件）创建一个SqlSessionFactory对象
	 * @throws IOException
	 */
	@Test
	public void test1() throws IOException {
		String source = "mybatis-config.xml";
		InputStream inputStream = Resources.getResourceAsStream(source);
		SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
		
		//获取sqlSession实例，能直接执行映射的sql语句
		SqlSession sqlSession = sqlSessionFactory.openSession();
		
		Employee employee = sqlSession.selectOne("com.pxxy.bean.mapper.EmployeeMapper.selectEmpById", 1);
		System.out.println(employee);
		
		sqlSession.close();
	}
}

　　10.运行test1()

二、接口式编程

　　以上操作可不变动

　　1.创建EmployeeMapper接口

 

 　　2.此时注意employee的sqlmapper中的命名空间是否是EmployeeMapper接口的全路径类名

　　3.在测试类中添加方法2

　　　　　@Test
	public void test2() throws IOException {
		String source = "mybatis-config.xml";
		InputStream inputStream = Resources.getResourceAsStream(source);
		SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
		
		//获取sqlSession实例，能直接执行映射的sql语句
		SqlSession sqlSession = sqlSessionFactory.openSession();
		
		EmployeeMapper employeeMapper = sqlSession.getMapper(EmployeeMapper.class);
		System.out.println(employeeMapper.selectEmpById(1));
		
		sqlSession.close();
	}

　　4.运行结果