MyBatis入门详解——附代码

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "mybatis-3-mapper.dtd" >
<mapper namespace="cn.smbms.dao.user.UserMapper">
	<!-- 映射器 -->
	<!-- 查询用户表总条数 -->
	<select id="count" resultType="int">
		select count(1) as count from
		smbms_user
	</select>


	<!-- 向smbms_user中插入数据 -->
	<insert id="add" parameterType="User">
		insert into smbms_user(userCode,userName,userPassword) values(#{userCode},#{userName},#{userPassword})
	</insert>

	<!-- 更新数据库 smbms_user中的用户名 -->
	<!-- <update id="update"> -->
	<!-- update smbms_user set userPassword=#{pwd} where -->
	<!-- id=#{id} -->
	<!-- </update> -->

	<!-- 根据用户的id 类跟新用户名称 prefix前缀，suffix后缀 -->
	<update id="update">
		update smbms_user
		<trim prefix="set" suffixOverrides="," suffix="where id=#{id}">
			<if test="userCode!=null and userCode!=‘‘">
				userCode=#{userCode},
			</if>
			<if test="userName!=null and userName!=‘‘">
				userName=#{userName}
			</if>
		</trim>
	</update>


	<!-- 删除smbms_user，用id查询删除 -->
	<delete id="delete">
		delete from smbms_user where id=#{id}
	</delete>

	
	
	
</mapper>

package cn.smbms.dao.user;

import java.io.IOException;
import java.io.InputStream;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

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 org.apache.log4j.Logger;
import org.junit.Before;
import org.junit.Test;

import cn.smbms.pojo.User;
import cn.smbms.utils.MyBatisUtil;

public class UserMapperTest {
	private Logger logger = Logger.getLogger(UserMapperTest.class);

	@Before
	// 加注释
	public void setUp() throws Exception {
	}

	
//向数据库中插入数据
@Test
	public void testadd() {
		SqlSession sqlSession = null;
		int count = 0;
		try {
			sqlSession = MyBatisUtil.createSqlSession();
			User user = new User();
			user.setUserCode("001");
			user.setUserName("张三");
			user.setUserPassword("123451245566");
			count = sqlSession.getMapper(UserMapper.class).add(user);
			sqlSession.commit();
		} catch (Exception e) {
			// TODO: handle exception
			e.printStackTrace();
			sqlSession.rollback();
		} finally {
			MyBatisUtil.closeSqlSession(sqlSession);
		}
		logger.debug("UserMapperTest count--->" + count);
	}

	// 更新数据第一种方法
//	public void testupdate() {
//		SqlSession sqlSession = null;
//		int count = 0;
//		try {
//			sqlSession = MyBatisUtil.createSqlSession();
//			count = sqlSession.getMapper(UserMapper.class).update(22, "123");
//			sqlSession.commit();
//		} catch (Exception e) {
//			// TODO: handle exception
//			e.printStackTrace();
//			sqlSession.rollback();
//		} finally {
//			MyBatisUtil.closeSqlSession(sqlSession);
//		}
//		logger.debug("UserMapperTest count--->" + count);
//	}

	// 第二种方法
	public void update() {
		SqlSession sqlSession = null;
		int count = 0;
		try {
			sqlSession = MyBatisUtil.createSqlSession();
			count = sqlSession.getMapper(UserMapper.class).update(" liuweigang ", "刘伟刚", 1);
			sqlSession.commit();
		} catch (Exception e) {
			// TODO: handle exception
			e.printStackTrace();
			sqlSession.rollback();
		} finally {
			MyBatisUtil.closeSqlSession(sqlSession);
		}
		logger.debug("UserMapperTest count--->" + count);
	}

	// 删除数据
	public void delete() {
		SqlSession sqlSession = null;
		int count = 0;
		try {
			sqlSession = MyBatisUtil.createSqlSession();
			count = sqlSession.getMapper(UserMapper.class).delete(22);
			sqlSession.commit();
		} catch (Exception e) {
			// TODO: handle exception
			e.printStackTrace();
			sqlSession.rollback();
		} finally {
			MyBatisUtil.closeSqlSession(sqlSession);
		}
		logger.debug("UserMapperTest count--->" + count);
	}

}

package cn.smbms.utils;

import java.io.IOException;
import java.io.InputStream;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

public class MyBatisUtil {
	private static SqlSessionFactory factory;
	static {// 静态状态下，factory只会创建一次
		try {
			InputStream is = Resources.getResourceAsStream("mybatis-config.xml");
			factory = new SqlSessionFactoryBuilder().build(is);
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

	public static SqlSession createSqlSession() {
		return factory.openSession(false);// false关闭自动提交
	}

	public static void closeSqlSession(SqlSession sqlSession) {
		sqlSession.close();
	}

}

log4j.rootLogger=debug, stdout, R

log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout

log4j.appender.stdout.layout.ConversionPattern=%5p - %m%n

log4j.appender.R=org.apache.log4j.RollingFileAppender
log4j.appender.R.File=firestorm.log

log4j.appender.R.MaxFileSize=100KB
log4j.appender.R.MaxBackupIndex=1

log4j.appender.R.layout=org.apache.log4j.PatternLayout
log4j.appender.R.layout.ConversionPattern=%p %t %c - %m%n

log4j.logger.com.codefutures=DEBUGr.stdout.layout.ConversionPattern=%5p [%t] - %m%n