package mybatis.test;

import java.io.IOException;
import java.io.Reader;

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

/** 通过单例模式管理SqlSessionFactory对象 */
public class SqlSessionFactoryUtil {
	private SqlSessionFactoryUtil() {
	}

	/* 恶汉式 */
	private static SqlSessionFactory sqlSessionFactory;
	static {
		Reader reader;
		try {
			reader = Resources.getResourceAsReader("mybatisConfig.xml");
			SqlSessionFactoryBuilder builder = new SqlSessionFactoryBuilder();
			sqlSessionFactory = builder.build(reader);
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
	public static SqlSessionFactory getSqlSessionFactoryInstance() {
			return sqlSessionFactory;
	}
	/*
	 * 懒汉式： 
	 * private static SqlSessionFactory sqlSessionFactory = null;
	 * //synchronized 防并发 
	 * public synchronized static SqlSessionFactory getSqlSessionFactoryInstance() { 
	 * 		if (sqlSessionFactory != null) { 
	 * 			return sqlSessionFactory; 
	 * } else { 
		   Reader reader; 
		   try { 
		   reader = Resources.getResourceAsReader("mybatisConfig.xml"); 
		   SqlSessionFactoryBuilder
		   builder = new SqlSessionFactoryBuilder(); 
		   sqlSessionFactory = builder.build(reader); 
		   } catch (IOException e) { 
		   		e.printStackTrace(); }
		    	return sqlSessionFactory; 
		 * } 
	 * }
	 */
}