beanfactory.java

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package com.briup.util;

import java.io.IOException;
import java.lang.reflect.Constructor;
import java.util.Properties;

import com.briup.dao.IDao;
import com.briup.service.IService;
import com.briup.transaction.Transaction;
/**
 * 
 * 通过工厂方式获取实例对象
 * @author Administrator
 *
 */
public class BeanFactory {
	private static IDao dao;

	private static IService service;
	
	private static Transaction tran;
	/*
	 * @return dao的实例
	 */
	public static IDao getDao() throws Exception {
		Properties props = getProperties();
		String className = props.getProperty("DaoImpl");
		if (dao == null)
			dao = (IDao) Class.forName(className).newInstance();
		return dao;
	}
	/*
	 * @return service的实例
	 */
	/**
	 * @return Iservire
	 * @throws Exception
	 */
	public static IService getService() throws Exception {
		Properties props = getProperties();
		String classNameImpl = props.getProperty("ServiceImpl");
		String classNameProxy = props.getProperty("ServiceProxy");
		IService iService = null;
		if (service == null) {
			iService = (IService) Class.forName(classNameImpl).newInstance();
			Constructor constructor = Class.forName(classNameProxy)
					.getConstructor(IService.class);
			service = (IService) constructor
					.newInstance(new Object[] { iService });
		}
		return service;
	}
	/**
	 * @return Transaction
	 * @throws Exception
	 */
	/*
	 * @return 事务类实例
	 */
	public static Transaction getTransaction()throws Exception{
		Properties props = getProperties();
		String className = props.getProperty("TransactionImpl");
			tran = (Transaction) Class.forName(className).newInstance();
		return tran;
	}
	/*
	 * 从woss.txt文件中加载以等号分割的信息为键值对
	 * @return Properties封装的键值对
	 */
	private static Properties getProperties() {
		Properties props = new Properties();
		try {
			props.load(BeanFactory.class.getResourceAsStream("../woss.txt"));
		} catch (IOException e) {
			e.printStackTrace();
		}
		return props;
	}

	public static void main(String[] args) {
		try {
			System.out.println(getDao());
			System.out.println(getService());
			System.out.println(getTransaction());
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}