dubbo-cluster/src/main/java/org/apache/dubbo/rpc/cluster/loadbalance/
ConsistentHashLoadBalance.java
![image](https://user-images.githubusercontent.com/30815149/55045041-740f4980-5077-11e9-8b6c-7a2b18b0d58e.png)
我看其他地方都是用Constants进行替换，这里是不是可以使用Constants类里的属性进行替换
}
        private Invoker<T> selectForKey(long hash) {
            Map.Entry<Long, Invoker<T>> entry = virtualInvokers.ceilingEntry(hash);
            if (entry == null) {
                entry = virtualInvokers.firstEntry();
            }
            return entry.getValue();
        }
        private long hash(byte[] digest, int number) {
            return (((long) (digest[3 + number * 4] & 0xFF) << 24)
                    | ((long) (digest[2 + number * 4] & 0xFF) << 16)
                    | ((long) (digest[1 + number * 4] & 0xFF) << 8)
                    | (digest[number * 4] & 0xFF))
                    & 0xFFFFFFFFL;
        }
        private byte[] md5(String value) {
            MessageDigest md5;
            try {
                md5 = MessageDigest.getInstance("MD5");
            } catch (NoSuchAlgorithmException e) {
                throw new IllegalStateException(e.getMessage(), e);
            }
            md5.reset();
            byte[] bytes = value.getBytes(StandardCharsets.UTF_8);
            md5.update(bytes);
            return md5.digest();
        }
    }
}