mybatis中autoCommit自动提交事务

今天学习了下mybatis，

对其中的autoCommit自动提交事务比较好奇，

研究了下，把配置和代码都放上

mapper.xml如下：

<?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隔离sql -->
<mapper namespace="User">
    <!-- id:statement的标识 -->
    <!-- 
      #{}表示占位符(转为?)，可以防止SQL注入；如果输入参数类型是简单类型，输入参数名称可以是value或者其它任意名称 
     -->
    <select id="getUserById" parameterType="int" resultType="org.pine.mybatis.po.User">
        select * from user t where t.id = #{id}
    </select>

    <!-- resultType：单条记录的类型 -->
    <select id="listUserByUserame1" parameterType="java.lang.String" resultType="org.pine.mybatis.po.User">
        select * from user t where t.username like #{username}
    </select>

    <!-- 
      ${}表示拼接SQL(拼接参数),不能防止SQL注入；如果输入参数类型是简单类型，输入参数名称只能是value 
     -->
    <select id="listUserByUsername2" parameterType="java.lang.String" resultType="org.pine.mybatis.po.User">
        select * from user t where t.username like '%${value}%'   
    </select>
    
    <!-- 
             输入参数类型为User类型，是一个pojo
     #{}表示占位符，输入参数名称为username，是pojo里面的一个属性
     -->
    <insert id="insertUser0" parameterType="org.pine.mybatis.po.User">
        INSERT INTO USER(username,birthday,sex,address) VALUES(#{username},#{birthday},#{sex},#{address})
    </insert>

    <insert id="insertUser1" parameterType="org.pine.mybatis.po.User">
        INSERT INTO USER(id,username,birthday,sex,address) VALUES(default,#{username},#{birthday},#{sex},#{address})    
    </insert>
    
    <insert id="insertUser2" parameterType="org.pine.mybatis.po.User">
        INSERT INTO USER(id,username,birthday,sex,address) VALUES(null,#{username},#{birthday},#{sex},#{address});
    </insert>
</mapper>

MybatisFirst3.java如下：

package org.pine.mybatis.first;

import java.io.InputStream;
import java.sql.Date;
import java.text.SimpleDateFormat;

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.junit.Test;
import org.pine.mybatis.po.User;

public class MybatisFirst3 {
    @Test
    public void testInsert0() throws Exception{
      String fileName ="SqlMapConfig.xml";
      InputStream inputStream = Resources.getResourceAsStream(fileName); 
      SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
      SqlSession sqlSession = sqlSessionFactory.openSession();//通过这种方式打开的SqlSession，autoCommit默认为false，需要手动提交事务
      
      User user = new User();
      user.setUsername("孙坤鹏");
      user.setBirthday(new Date(new SimpleDateFormat("yyyy-MM-dd").parse("1991-09-13").getTime()));
      user.setSex("男");
      user.setAddress("河南新乡");
      
      sqlSession.insert("User.insertUser2", user);
      sqlSession.commit();
      
      sqlSession.close();
      inputStream.close();
    } 
    
    @Test
    public void testInsert1() throws Exception{
        String fileName ="SqlMapConfig.xml";
        InputStream inputStream = Resources.getResourceAsStream(fileName); 
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        SqlSession sqlSession = sqlSessionFactory.openSession(true);//通过这种方式打开的SqlSession，autoCommit为true，会自动提交事务
        
        User user = new User();
        user.setUsername("王起鹏");
        user.setBirthday(new Date(new SimpleDateFormat("yyyy-MM-dd").parse("1992-07-20").getTime()));
        user.setSex("男");
        user.setAddress("河南驻马店");
        
        sqlSession.insert("User.insertUser2", user);
        
        sqlSession.close();
        inputStream.close();
    }
    
    @Test
    public void testInsert2() throws Exception{

        String fileName ="SqlMapConfig.xml";
        InputStream inputStream = Resources.getResourceAsStream(fileName); 
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        SqlSession sqlSession = sqlSessionFactory.openSession(false);//通过这种方式打开的SqlSession，autoCommit为false，需要手动提交事务
        
        User user = new User();
        user.setUsername("杨豆豆");
        user.setBirthday(new Date(new SimpleDateFormat("yyyy-MM-dd").parse("1989-06-19").getTime()));
        user.setSex("男");
        user.setAddress("河南驻马店");
        
        sqlSession.insert("User.insertUser2", user);
        sqlSession.commit();
        
        sqlSession.close();
        inputStream.close();
            
    }
}