一次更换BeanUtils引发的惨案

原由是这样的，原先代码里copyProperties用的是 org.apache.commons.beanutils.BeanUtils，奈何这位老哥不太给力，source里的Date类型如果为空的话会报错。于是给改用了org.springframework.beans.BeanUtils; 结果线上发生了一个匪夷所思的问题。看下面代码：

 Subject subject = SecurityUtils.getSubject();                
Object principal =  subject.getPrincipal();
            log.info("principals is {}",JsonUtil.toJSONString(subject.getPrincipals().asSet().toArray()));
            if(principal != null) {
                ShopguideUser user=(ShopguideUser)principal;
                log.info("user = {}", JsonUtil.toJSONString(user));
                BeanUtils.copyProperties(userInfo，user);
                ShopguideUserAccount account = accountService.getUserAccount(user.getId());
                BeanUtils.copyProperties(account,userInfo );
                return userInfo;    

我这里因为想统一通过dubbo的filter传一些参数：

@Activate(group = {Constants.CONSUMER},order = -10000)
@Slf4j
public class ConsumerFilter implements Filter {
    @Override
    public Result invoke(Invoker<?> invoker, Invocation invocation) throws RpcException {
        try {
//            RpcInvocation invocation1 = (RpcInvocation) invocation;
            Subject subject = SecurityUtils.getSubject();
            ShopguideUser user = null;

            Object principal =  subject.getPrincipal();
            if(!subject.isAuthenticated()) {
                log.info("not authenticated principal = {}",principal);
            }else{
                log.info("authenticated principal = {}",principal);
            }

            if(principal != null) {
                log.info("principal = {}", JsonUtil.toJSONString(principal));
                log.info("principals is {}",JsonUtil.toJSONString(subject.getPrincipals().asSet().toArray()));
                user=(ShopguideUser)principal;
                RpcContext.getContext().setAttachment( Constant.AUTH_USER, user.getId().toString());
            }

但这上面的principal明明有值，到了ConsumerFilter的principal就是个空对象{}了？ 因为运行这两段程序绝对是在一个线程里发生的。怎么principal平白无故被改了？原来坑爹的是spring的BeanUtils的参数和apache的是相反的，user对象被覆盖了，变成了空对象！血的教训。