public class Sharded{private object nodes_lock = new object();private RedBlackTreeMap<long, string> nodes = new RedBlackTreeMap<long, string>();private IHash hashAlgo = new MD5_LongSUM_Multiply_Hash();public void AddTarget(int index, string shard){lock (nodes_lock){for (int n = 0; n < 160; ++n){var hashKey = "SHARD-" + index + "-NODE-" + n;long hashValue = this.hashAlgo.Hash(hashKey);nodes.SetOrAddValue(hashValue, shard);}}}public string GetShardInfo(string key){long searchHashKey = this.hashAlgo.Hash(key);long nearestKey;string shard;lock (nodes_lock){if (this.nodes.NearestGreater(searchHashKey, out nearestKey)){shard = this.nodes.GetValue(nearestKey);return shard;}if (this.nodes.Least(out searchHashKey, out shard))return shard;}throw new Exception("GetShardInfo exception");}}

public class MD5_LongSUM_Multiply_Hash : IHash{public long Hash(string key){var md5= Md5Hash(key);if (string.IsNullOrEmpty(md5))Log.GetLog().Info("Hash, md5 is null or empty");var convertedKeyBytes = Encoding.UTF8.GetBytes(md5);long value = 1;foreach(var b in convertedKeyBytes)value *= b*-1;return value;}private string Md5Hash(string input){MD5CryptoServiceProvider md5Hasher = new MD5CryptoServiceProvider();if (string.IsNullOrEmpty(input))Log.GetLog().Info("Md5Hash, input is null or empty");byte[] data = md5Hasher.ComputeHash(Encoding.Default.GetBytes(input));StringBuilder sBuilder = new StringBuilder();for (int i = 0; i < data.Length; i++){sBuilder.Append(data[i].ToString("x2"));}return sBuilder.ToString();}}

import org.springframework.security.authentication.encoding.MessageDigestPasswordEncoder;
import redis.clients.util.Hashing;
import redis.clients.util.SafeEncoder;import java.io.UnsupportedEncodingException;/*** Created by z on 2017/4/12.*/
public class MD5_SUM_Hash implements Hashing {MessageDigestPasswordEncoder encoder=new MessageDigestPasswordEncoder("MD5");public long hash(String key) {return this.hash(SafeEncoder.encode(key));}public long hash(byte[] bytes) {String converted_str= null;try {converted_str = new String(bytes, "UTF8");} catch (UnsupportedEncodingException e) {e.printStackTrace();}String result=encoder.encodePassword(converted_str, null);try {bytes=result.getBytes("UTF8");} catch (UnsupportedEncodingException e) {e.printStackTrace();}long value = 1;for(byte b : bytes)value *= b*-1;return value;}
}

<dependency><groupId>org.springframework.security</groupId><artifactId>spring-security-core</artifactId></dependency>