基于java8函数式接口Function实现MyBatisUtils

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 java.io.IOException;
import java.io.Reader;
import java.util.function.Function;

public class MybatisUtils {
    //利用static属于类，不属于对象，且全局唯一
    private static SqlSessionFactory sqlSessionFactory=null;
    //利用静态块在初始化类时实例化sqlSessionFactory
    static {
        Reader reader=null;
        try{
            reader= Resources.getResourceAsReader("mybatis-config.xml");
            sqlSessionFactory =new SqlSessionFactoryBuilder().build(reader);
        }catch (IOException e){
            throw new ExceptionInInitializerError(e);
        }
    }

    
    public static Object executeQuery(Function func){
        SqlSession sqlSession = sqlSessionFactory.openSession();
        try {
            Object obj = func.apply(sqlSession);
            return obj;
        }finally {
            sqlSession.close();
        }
    }

    
    public static Object executeUpdate(Function func){
        SqlSession sqlSession = sqlSessionFactory.openSession(false);
        try {
            Object obj = func.apply(sqlSession);
            sqlSession.commit();
            return obj;
        }catch (RuntimeException e){
            sqlSession.rollback();
            throw e;
        }finally {
            sqlSession.close();
        }
    }

}