Struts2+Mybatis+Freemarker+Tiles架构灵活的开发框架(五)

推荐的文件分层结构如下
com.XXX.lib.action   主要放置Action，控制前台跳转
com.XXX.lib.cservice 主要放置Service,实现业务逻辑
com.XXX.lib.dao      主要放置dao,实现数据库操作
com.XXX.lib.emodel   主要放置Model,实现模型操作
com.XXX.lib.fintface 主要放置interface,定义接口
com.XXX.lib.global   主要放置全局共享类和管理者
com.XXX.lib.global.constant 主要放置全局变量
com.XXX.lib.global.proxy    主要放置全局代理
com.XXX.lib.mybatis         主要放置Mybatis对象

接着上面的，完成mybatis链接
globalManager如下

package com.XXX.lib.global;

import org.apache.ibatis.session.SqlSessionFactory;

public class GlobalManager {
	private static GlobalManager instance = null;
	public static void setInstance(GlobalManager instance) {
		GlobalManager.instance = instance;
	}
	public static GlobalManager getInstance() {//synchronized防止多线程错误  synchronized 
		if(instance == null){//第一次调用被实例化，以后再也不会被实例化了
			instance = new GlobalManager();
			instance.init();
		}
		return instance;
	}
	public SqlSessionFactory sqlSessionFactory;//全局sqlSessionFactory
	public void init(){
		sqlSessionFactory = (new SqlSesFacBuilder()).GetFactory();//获得一个SqlSessionFactory,对全局可见	
	}
}

SqlSesFacBuilder代码如下

package com.XXX.lib.global;

import java.io.Reader;

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

import com.XXX.lib.global.constant.MybatisConstant;

public class SqlSesFacBuilder {
	public SqlSessionFactory GetFactory(){
		SqlSessionFactory sqlSessionFactory=null;
		try{
			//配置路径
			String resource = MybatisConstant.MybatisResource;
			//加载配置文件
			Reader reader = Resources.getResourceAsReader(resource);
			//生成一个SqlSessionFactory
			sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
		}catch(Exception e){
			e.printStackTrace();
		}
		return sqlSessionFactory;
	}
}

MybatisConstant如下

package com.XXX.lib.global.constant;

public class MybatisConstant {
	public final static String MybatisResource = "com/XXX/lib/mybatis/Configuration.xml";
}

SqlSessionProxy如下

package com.XXX.lib.global.proxy;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;

import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;

import com.XXX.lib.global.GlobalManager;

public class SqlSessionProxy implements InvocationHandler{
	private Object proxyobj;
	public SqlSessionProxy(Object obj){
		proxyobj = obj;
	}
	/**
	 * @param obj
	 * @return
	 * 静态工厂方法
	 */
	public static Object factory(Object obj){
		Object result = null;
		Class<?> cls = obj.getClass();
		result =  Proxy.newProxyInstance(cls.getClassLoader(), cls.getInterfaces(), new SqlSessionProxy(obj));
		return result;
	}
	/**
	 * Java反射方法
	 */
	public Object invoke(Object proxy, Method method, Object[] args)throws Throwable {
		Object result;
		try{
			SqlSessionFactory sqlSessionFactory= GlobalManager.getInstance().sqlSessionFactory;     
            SqlSession sqlSession = sqlSessionFactory.openSession(true);//打开一个SqlSession,true代表自动提交
            args[0] = sqlSession;//改变第一个参数的值
            result = method.invoke(proxyobj, args);
            sqlSession.close();//关闭一个SqlSession
        }catch(InvocationTargetException e){
        	e.printStackTrace();
            throw e.getTargetException();
        }catch(Exception e){
        	e.printStackTrace();
            throw new RuntimeException("unexpected invocation exception: " + e.getMessage());
        }
        return result;
	}
}

一个mybatis配置实例如下

<?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">
<mapper namespace="com.XXX.lib.fintface.common.CommonIntface">
	<select id="lodgCateList" parameterType="HashMap" resultType="HashMap">
               SELECT * FROM EMP
	</select>
</mapper>