关于BeanUtil.copyProperties性能

BeanUtil.copyProperties 方法确实很方便，代码写出来非常优美，不会有很多的get set,但由于用到反射，可能存在潜在的性能问题。因此对spring 和 commons的BeanUtil.copyProperties进行了对照测试，代码大致如下：

@Test
	public void copyPropertiesTest() throws IllegalAccessException, InvocationTargetException {

		po = new PromotionPO();
		Timestamp now = new Timestamp(System.currentTimeMillis());
		model = RetailmodelFactory.eINSTANCE.createPromotion();
//get/set
		Long startTime = System.currentTimeMillis();
		for (int i = 0; i < LOOP_NUMBER; i++) {
			model.setCode("code");
			model.setDescription("haha");
			model.setDiscount(5.4);
			model.setEndTime(now);
			model.setID(39578395L);
			model.setPriority(1);
			model.setPromotionType(3);
			model.setStartTime(now);
			model.setSupplierID("123245L");
		}
		Long endTime = System.currentTimeMillis();
		traditionalCopyTIme = endTime - startTime;

//spring
		startTime = System.currentTimeMillis();
		for (int i = 0; i < LOOP_NUMBER; i++) {
			BeanUtils.copyProperties(model, po);
		}
		endTime = System.currentTimeMillis();
		springCopyPropertiesTime = endTime - startTime;

//commons		
		startTime = System.currentTimeMillis();
		for (int i = 0; i < LOOP_NUMBER; i++) {
			org.apache.commons.beanutils.BeanUtils.copyProperties(po,model);
		}
		endTime = System.currentTimeMillis();
		commonsCopyPropertiesTime = endTime - startTime;

		logger.info("normal copy Time: " +  traditionalCopyTIme + "ms.");
		logger.info("Spring BeanUtil copy Time: " +  springCopyPropertiesTime + "ms.");
		logger.info("Commons BeanUtil copy Time: " +  commonsCopyPropertiesTime + "ms.");
	}

当 LOOP_NUMBER = 50000时（即执行50000次copy），结果如下：
[table]
|编号|set/get|Spring BeanUtil|Commons BeanUtil|
|1|62ms|1703ms|63860ms|
|1|16ms|1359ms|62328ms|
|1|16ms|1359ms|63047ms|
|1|0ms|1390ms|63047ms|
|1|16ms|1375ms|62266ms|
[/table]

可看出Commons BeanUtil的copyProperties 性能最差，几乎不能忍受。spring的copyProperties有可能在接受范围内。直接set/get虽然丑陋，但是性能确实非常好，几乎可以忽略。
接下来对spring和commons两种不同实现进行分析。