mybatis connection factory classes implement java

EDITORIAL

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As used herein, the thing

1. mybatis
2. java

1. text

package com.etc.util;

import java.io.InputStream;
import java.sql.Connection;
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.lf5.util.Resource;

//实现获取、释放mybatis数据库连接的工具类
public class MyBatisSessionFactory {
	//定义常量
	private static String CONFIG_FILE_LOCATION="mybatis-config.xml";
	
	//考虑到该工具类允许被多线程执行。因为封装1个线程池，让每个线程从线程池中获取1个连接。让1个线程对应
	//1条数据库连接,这样更安全
	//ThreadLocal的作用：让"线程"绑定"资源",这样就不会出现多个线程同享资源的情况。更安全。牺牲内存，换取”安全“
	private static ThreadLocal<SqlSession> threadLocal = new ThreadLocal<SqlSession>();
	//Map<ThreadId,SqlSession> sessions;
	private static InputStream is; //用于读取配置文件的流对象
	
	private static SqlSessionFactory fac;//用于管理多个连接的工厂。一个工厂对应1个数据库。
	
	//在该类的静态段中加载配置文件，这样可以确保只执行1次。
	static
	{
		try {
			is = Resources.getResourceAsStream(CONFIG_FILE_LOCATION);//读取配置文件
			fac = new SqlSessionFactoryBuilder().build(is);//通过配置文件创建1个连接工厂
		} catch (Exception e) 
		{
			e.printStackTrace();
		}
		
	}
	//获取1条连接
	public static SqlSession getSession()
	{
		SqlSession s  = threadLocal.get(); //找线程池要1条连接
		if(s==null) //第1次时，拿不到，则由工厂获取1条连接并放入线程池
		{
			s = fac.openSession();//由工厂获取1条连接并放入线程池
			threadLocal.set(s);//放入线程池
		}
		return s;
	}
	//关闭连接
	public static void closeSession()
	{
		SqlSession s  = threadLocal.get();//找线程池要本线程对应的连接
		threadLocal.set(null);//将该连接从线程池中清除
		if(s!=null)
			s.close();//物理关闭连接
	}
}

		//如何获取连接？
		SqlSession session = MyBatisSessionFactory.getSession();
		//如何获取dao的实现类？
		UserinfoDao dao = session.getMapper(UserinfoDao.class);
		//按接口dao类的格式进行查询
		List<Userinfo> list = dao.findAll();
		//如果修改了数据库，要提交修改
		session.commit();
		//关闭连接
		MyBatisSessionFactory.closeSession();		

2. summary

A long time ago to write notes in the proper way cloud notes, ready to give it up, migrate notes to be here. There are ambiguities Comments welcome, I would see the reply. This article is over, what are deficiencies please feel free to correct me.