java 动态修改propertis文件

Properties props2 = new Properties();// 属性集合对象 
			fis =  new FileInputStream(path +  "/jeesite.properties");
			//必须要先获取properties，否则之前的properties内容将丢失
			props2.load(fis);
			
			
			if (fis != null) {
					fis.close();
		    } 
//fos 输出流必须要在 fis输入流关闭之后才能获取，否则将会把properties文件清空
			fos = new FileOutputStream(path +  "/jeesite.properties");
			Map<String ,String[]> map2 = request.getParameterMap();
    		for (Map.Entry<String, String[]> entry : map2.entrySet()) {  
    			 
    			//保存，并加入注释  
    			String key=entry.getKey();
    			if(key.equals("update")) continue;
    			props2.setProperty(key, entry.getValue()[0]);
    			props2.store(fos, "Update '" + key + "' value");  
    		  
    		}