一个通用工厂模式的优雅实现。。。= =

package com.itheima.utils;

import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;

public class DaoFactory {
	
	Properties pro =  new Properties();
	private static DaoFactory instance = new DaoFactory();
	private DaoFactory(){
		InputStream is = DaoFactory.class.getClassLoader().getResourceAsStream("dao.properties");
		try {
			pro.load(is);
		} catch (IOException e) {
			throw new ExceptionInInitializerError(e);
		}
		
	}
	
	public static DaoFactory getInstance() {
		return instance;
	}
	
	public <T> T createDao(Class<T> clazz){
		String name = pro.getProperty(clazz.getSimpleName());
		if(name==null) {
			throw new RuntimeException("找不到与" + name +"匹配的类");
		}
		try {
			return (T)Class.forName(name).newInstance();
		} catch (Exception e) {
			throw new RuntimeException(e);
		}
			
	}
	
}

CustomerDao=com.itheima.dao.impl.CustomerDaoImpl
CustomerStatusDao=com.itheima.dao.impl.CustomerStatusDaoImpl
InfoSourceDao=com.itheima.dao.impl.InfoSourceDaoImpl