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：

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

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。