一致性哈希算法 JAVA 版简单验证

public class ConsistentHash {
    //模拟 10个物理物理节点 ip
    private Set<String> realIPNodes = new TreeSet<String>() {{
            add("192.168.1.1");
            add("192.168.1.2");
            add("192.168.1.3");
            add("192.168.1.4");
            add("192.168.1.5");
            add("192.168.1.6");
            add("192.168.1.7");
            add("192.168.1.8");
            add("192.168.1.9");
            add("192.168.1.10");
        }
    };
    private final int copies = 100000; // 复制倍数
    private TreeMap<Long, String> virtualNodes = new TreeMap<>(); // 哈希值 －＞ 物理节点
    private static Long FNVHash(String key) {
        final int p = 16777619;
        Long hash = 2166136261L;
        for (int idx = 0, num = key.length(); idx < num; ++idx) {
            hash = (hash ^ key.charAt(idx)) * p;
        }
        hash += hash << 13;
        hash ^= hash >> 7;
        hash += hash << 3;
        hash ^= hash >> 17;
        hash += hash << 5;
        if (hash < 0) {
            hash = Math.abs(hash);
        }
        return hash;
    }
    // 根据物理节点，构建虚拟节点映射关系
    public ConsistentHash() {
        for (String nodeIp : realIPNodes) {
            addPhysicalNode(nodeIp);
        }
    }
    // 添加物理节点
    public void addPhysicalNode(String nodeIp) {
        for (int idx = 0; idx < copies; ++idx) {
            long hash = FNVHash(nodeIp + "#" + idx);
            virtualNodes.put(hash, nodeIp);
        }
    }
    // 查找对象映射的节点
    public String getObjectNode(String object) {
        long hash = FNVHash(object);
        SortedMap<Long, String> tailMap = virtualNodes.tailMap(hash); // 所有大于 hash 的节点
        Long key = tailMap.isEmpty() ? virtualNodes.firstKey() : tailMap.firstKey();
        return virtualNodes.get(key);
    }
    // 统计对象与节点的映射关系
    public void dumpObjectNodeMap(int objectMin, int objectMax) {
        // 统计
        Map<String, Integer> objectNodeMap = new TreeMap<>(); // IP => COUNT
        for (int object = objectMin; object <= objectMax; ++object) {
            String nodeIp = getObjectNode(Integer.toString(object));
            Integer count = objectNodeMap.get(nodeIp);
            objectNodeMap.put(nodeIp, (count == null ? 0 : count + 1));
        }
        double totalCount = objectMax - objectMin + 1;
        for (Map.Entry<String, Integer> entry : objectNodeMap.entrySet()) {
            double percent =  (100 * entry.getValue() / totalCount);
            System.out.println("IP=" + entry.getKey() + ": 命中率=" + percent + "%");
        }
    }
    public static void main(String[] args) {
        ConsistentHash ch = new ConsistentHash();
         ch.dumpObjectNodeMap( 0, 1000000);
    }
}