MybatisSqlSessionFactory类来得到Mybatis的session对象

/**
 * 
 */
package com.hotelmanagement.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 MybatisSqlSessionFactory {
	
	private static SqlSession session;
	private static SqlSessionFactory factory;
	/*静态块只进入一次 因为session的开销太大，session可以共享，所以进入一次即可*/
	static{
		InputStream is = null;
		try {
			is = Resources.getResourceAsStream("mybatis-config.xml");
			factory = new SqlSessionFactoryBuilder().build(is);
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally{
			if(is != null){
				try {
					is.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
		}
	}

	/**
	 * 
	 */
	public MybatisSqlSessionFactory() {
		// TODO Auto-generated constructor stub
	}
	
    //如果使用中session丢失重新获取
	public static void rebuildSqlSessionFactory(){
		InputStream is = null;
		try {
			is = Resources.getResourceAsStream("mybatis-config.xml");
			factory = new SqlSessionFactoryBuilder().build(is);
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally{
			if(is != null){
				try {
					is.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
		}
	}
	
	/**
	 * 获取SqlSession实例
	 * @return SqlSession
	 */
	public static SqlSession getSession(){
		if(factory == null){
			rebuildSqlSessionFactory();
		}
		session = factory.openSession();
		return session;
	}
	
	/**
	 * 释放资源
	 */
	public static void close(){
		if(session != null){
			session.close();
		}
	}

}