Java tutorial
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We also recommend that a file or class name and description of purpose be included on the same "printed page" as the copyright notice for easier identification within third-party archives. Copyright 2012 Eric Haddad Koenig Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. */ package com.all.dht; import static com.all.dht.DhtConstants.DELETE_DHT_VALUE_REQUEST_TYPE; import static com.all.dht.DhtConstants.DELETE_OVERSIZED_DHT_VALUE_REQUEST_TYPE; import static com.all.dht.DhtConstants.DHT_PRIMARY_KEY; import static com.all.dht.DhtConstants.IS_OVERSIZED_VALUE; import static com.all.dht.DhtConstants.OVERSIZED_DHT_VALUE_REQUEST_TYPE; import static com.all.dht.DhtConstants.OVERSIZED_DHT_VALUE_RESPONSE_TYPE; import static com.all.dht.DhtConstants.PUT_DHT_OVERSIZED_VALUE_REQUEST_TYPE; import static com.all.networking.NetworkingConstants.MESSAGE_SENDER; import java.io.IOException; import java.io.Serializable; import java.net.InetAddress; import java.net.InetSocketAddress; import java.net.SocketAddress; import java.security.GeneralSecurityException; import java.util.Collection; import java.util.Collections; import java.util.Date; import java.util.HashMap; import java.util.HashSet; import java.util.List; import java.util.Map; import java.util.Set; import java.util.TreeSet; import javax.annotation.PostConstruct; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.bouncycastle.util.Arrays; import org.limewire.mojito.EntityKey; import org.limewire.mojito.KUID; import org.limewire.mojito.MojitoDHT; import org.limewire.mojito.MojitoFactory; import org.limewire.mojito.db.DHTValue; import org.limewire.mojito.db.DHTValueEntity; import org.limewire.mojito.db.impl.DHTValueImpl; import org.limewire.mojito.io.MessageDispatcherFactoryImpl; import org.limewire.mojito.result.FindValueResult; import org.limewire.mojito.routing.Contact; import org.limewire.mojito.routing.RouteTable; import org.limewire.mojito.routing.Version; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Controller; import com.all.dht.database.AllEvictor; import com.all.dht.database.AllStorable; import com.all.dht.database.OversizedStorable; import com.all.dht.database.OversizedValueInfo; import com.all.dht.database.StorageDaemon; import com.all.dht.settings.DhtSettings; import com.all.dht.util.DhtFileUtils; import com.all.dht.util.Digest; import com.all.messengine.MessEngine; import com.all.messengine.MessageListener; import com.all.messengine.impl.DefaultMessEngine; import com.all.networking.NetworkingSocketFactory; import com.all.networking.PeerNetworkingService; import com.all.networking.util.MinaIoFactory; import com.all.shared.json.JsonConverter; import com.all.shared.model.AllMessage; import com.all.shared.model.UltrapeerNode; @Controller public class DhtManager { private static final String ALL_DHT_NAME = "ALL-DHT"; private static final int DISCOVERY_REQUEST_DELAY = 5000; private static final long DEFAULT_OVERSIZED_VALUE_AWAIT_TIME = 100; @Autowired private DhtSettings dhtSettings; @Autowired private DhtDiscovery dhtDiscovery; @Autowired private DhtBootstrapper bootstrapper; @Autowired private StorageDaemon storageDaemon; @Autowired private DhtFileUtils dhtFileUtils; @Autowired private PeerNetworkingService networkingService; @Autowired private NetworkingSocketFactory socketConfigurator; @Autowired private MessEngine messEngine; @Autowired private DhtMessageDispatcher dispatcher; private String dhtNodeId; private final MojitoDHT dht; private final Map<String, String> storedKeys = new HashMap<String, String>(); private final Set<String> oversizedValueRequests = new TreeSet<String>(); private final Log log = LogFactory.getLog(this.getClass()); public DhtManager() { dht = MojitoFactory.createDHT(ALL_DHT_NAME); dht.getEvictorManager().addEvictor(DhtSettings.ALL_TYPE, new AllEvictor()); dht.setMessageDispatcher(new MessageDispatcherFactoryImpl()); } @PostConstruct public void initialize() throws IOException { initCollaborators(); registerMessageListeners(); } private void initCollaborators() throws IOException { if (!isInitialized()) { dhtSettings = DhtSettings.getInstance(); socketConfigurator = new NetworkingSocketFactory(new MinaIoFactory()); bootstrapper = new DhtBootstrapper(); dhtDiscovery = new DhtDiscovery(dhtSettings); dhtFileUtils = new DhtFileUtils(dhtSettings); DefaultMessEngine defaultEngine = new DefaultMessEngine(); defaultEngine.init(); messEngine = defaultEngine; networkingService = new PeerNetworkingService(socketConfigurator, messEngine); storageDaemon = new StorageDaemon(dhtSettings, dhtFileUtils, networkingService); dispatcher = new DhtMessageDispatcher(dhtSettings, messEngine, socketConfigurator); } } private void registerMessageListeners() { registerDeleteRequestsListener(); registerOversizedRequestsListeners(); registerUltrapeerListRequestListener(); } private void registerUltrapeerListRequestListener() { messEngine.addMessageListener(DhtConstants.CURRENT_ULTRAPEERS_SET_REQUEST_TYPE, new MessageListener<AllMessage<Serializable>>() { @Override public void onMessage(AllMessage<Serializable> message) { processUltrapeersListRequest(); } }); } private void processUltrapeersListRequest() { List<DhtNode> dhtNodesList = dhtDiscovery.getDhtNodesList(); HashSet<UltrapeerNode> currentUltrapeers = new HashSet<UltrapeerNode>(); for (DhtNode dhtNode : dhtNodesList) { currentUltrapeers.add(new UltrapeerNode(dhtNode.getHostAddress())); } messEngine.send(new AllMessage<HashSet<UltrapeerNode>>(DhtConstants.CURRENT_ULTRAPEERS_SET_RESPONSE_TYPE, currentUltrapeers)); } private void registerOversizedRequestsListeners() { messEngine.addMessageListener(PUT_DHT_OVERSIZED_VALUE_REQUEST_TYPE, new MessageListener<AllMessage<String>>() { @Override public void onMessage(AllMessage<String> message) { putOversizedByRemoteNodeRequest(message); } }); messEngine.addMessageListener(OVERSIZED_DHT_VALUE_RESPONSE_TYPE, new MessageListener<AllMessage<String>>() { @Override public void onMessage(AllMessage<String> message) { String senderId = message.getProperty(MESSAGE_SENDER); if (senderId != null && !senderId.equals(dht.getLocalNodeID().toHexString())) { processOversizedValueResponse(message); } } }); messEngine.addMessageListener(OVERSIZED_DHT_VALUE_REQUEST_TYPE, new MessageListener<AllMessage<String>>() { @Override public void onMessage(AllMessage<String> message) { processOversizedValueRequest(message); } }); messEngine.addMessageListener(DELETE_OVERSIZED_DHT_VALUE_REQUEST_TYPE, new MessageListener<AllMessage<String>>() { @Override public void onMessage(AllMessage<String> message) { dhtFileUtils.removeFromFileSystem(message.getBody()); } }); } private void registerDeleteRequestsListener() { messEngine.addMessageListener(DELETE_DHT_VALUE_REQUEST_TYPE, new MessageListener<AllMessage<String>>() { @Override public void onMessage(AllMessage<String> message) { log.info("Processing DELETE_DHT_VALUE_REQUEST_TYPE for key : " + message.getBody()); processDeleteDhtValueRemoteRequest(message); } }); } public boolean isInitialized() { for (Object collaborator : new Object[] { dhtSettings, dhtDiscovery, bootstrapper, storageDaemon, messEngine, dispatcher, socketConfigurator }) { if (collaborator == null) { return false; } } return true; } public void start() { if (!isInitialized()) { throw new IllegalStateException("The DhtManager has not been Initialized."); } if (isRunning()) { return; } try { startDht(); startCollaborators(); getDhtNodesList(); subscribeToCurrentDhtNodes(); awaitBootstrapp(); backupRouteTable(); acceptTcpRequests(); } catch (Exception err) { throw new IllegalStateException("Could not start DHT Manager.", err); } log.info("DhtManager has started succesfully"); } private void acceptTcpRequests() throws IOException, GeneralSecurityException { dispatcher.start(); } private void awaitBootstrapp() throws InterruptedException { while (!isBootstrapped()) { log.info("Waiting for DHT nodes to bootstrap..."); Thread.sleep(DISCOVERY_REQUEST_DELAY); if (!isBootstrapped()) { getDhtNodesList(); } } } private void subscribeToCurrentDhtNodes() { if (dhtSettings.isAnnounceRequired()) { dhtNodeId = dhtDiscovery.subscribeDhtNode(dhtSettings.getDhtNode()); } } private void startDht() throws IOException { loadRouteTable(); InetSocketAddress nodeAddress = new InetSocketAddress(dhtSettings.getUdpPort()); dht.bind(nodeAddress); dht.start(); } private void startCollaborators() { bootstrapper.start(dht); storageDaemon.start(dht); } private void loadRouteTable() { if (dhtSettings.isAnyRouteTable()) { try { RouteTable routeTable = dhtFileUtils.readRouteTable(dhtSettings.getRouteTableFile()); if (routeTable != null) { log.info("Setting DHT route table from stored file."); dht.setRouteTable(routeTable); } } catch (Exception ignored) { log.error("Could not load Dht from file.", ignored); } } } private void backupRouteTable() { if (dhtSettings.isPersistRouteTableEnabled()) { try { RouteTable routeTable = null; synchronized (dht) { routeTable = dht.getRouteTable(); } log.info("Storing RouteTable in " + dhtSettings.getRouteTableFile()); dhtFileUtils.storeRouteTable(dhtSettings.getRouteTableFile(), routeTable); } catch (Exception e) { log.error("Could not save DHT RouteTable to file system.", e); } } } public boolean isRunning() { return dht != null && dht.isRunning(); } public boolean isBootstrapped() { return dht != null && dht.isBootstrapped(); } public void stop() { if (isRunning()) { unsuscribeFromCurrentDhtNodes(); stopAcceptingTcpRequests(); stopCollaborators(); stopDht(); } } private void stopDht() { log.info("Will Close DHT instance..."); dht.close(); backupRouteTable(); } private void stopAcceptingTcpRequests() { dispatcher.stop(); } private void stopCollaborators() { bootstrapper.stop(); storageDaemon.shutdown(); } private void unsuscribeFromCurrentDhtNodes() { if (dhtSettings.isAnnounceRequired()) { dhtDiscovery.unsubscribeDhtNode(dhtNodeId); } dhtNodeId = null; } public <T> Set<T> get(String primaryKey, Class<T> clazz) { Set<DHTValueEntity> valueEntities = get(createKUIDFromString(primaryKey)); Set<T> results = new HashSet<T>(); for (DHTValueEntity valueEntity : valueEntities) { results.add(readDhtValue(valueEntity.getValue(), clazz)); } return results; } public <T> T getLocalValue(String primaryKey, Class<T> clazz) { log.debug("Looking for key " + primaryKey + " in DHT locally!!!..."); DHTValue dhtValue = getLocalValue(createKUIDFromString(primaryKey)); return dhtValue != null ? readDhtValue(dhtValue, clazz) : null; } public <T> void put(String primaryKey, T value) { KUID key = createKUIDFromString(primaryKey); log.info("Storing " + primaryKey + "in DHT."); storedKeys.put(key.toHexString(), primaryKey); put(key, writeDhtValue(value)); } /* * Saves the given kademlia key in the DHT database synchronously and without * replication. */ public <T> void save(String kuid, T value) { DHTValue dhtValue = new DHTValueImpl(DhtSettings.ALL_TYPE, Version.ZERO, JsonConverter.toJson(value).getBytes()); DHTValueEntity valueEntity = DHTValueEntity.createFromValue(dht, KUID.createWithHexString(kuid), dhtValue); dht.getDatabase().store(valueEntity); } /* * Deletes the given kademlia key in the DHT database synchronously and * without replication. */ public void delete(String kuid) { dht.getDatabase().remove(KUID.createWithHexString(kuid), dht.getLocalNodeID()); } /* * Searchs for the given kademlia key in all the known nodes and return the * results of the specified class. */ public <T> Set<T> find(String kuid, Class<T> clazz) { Set<DHTValueEntity> valueEntities = get(KUID.createWithHexString(kuid)); Set<T> results = new HashSet<T>(); for (DHTValueEntity valueEntity : valueEntities) { results.add(readDhtValue(valueEntity.getValue(), clazz)); } return results; } public void removeLocal(String primaryKey) { if (hasLocalValue(primaryKey)) { KUID key = createKUIDFromString(primaryKey); remove(key); } } public void removeOthers(String primaryKey) { Set<DHTValueEntity> allEntities = get(createKUIDFromString(primaryKey)); for (DHTValueEntity valueEntity : allEntities) { if (!isLocalValue(valueEntity)) { removeRemoteEntity(valueEntity, false); } } } public void removeAll(String primaryKey) { removeLocal(primaryKey); removeOthers(primaryKey); } private void removeRemoteEntity(DHTValueEntity valueEntity, Boolean oversized) { AllMessage<String> deleteMessage = new AllMessage<String>(DELETE_DHT_VALUE_REQUEST_TYPE, valueEntity.getPrimaryKey().toHexString()); deleteMessage.putProperty(IS_OVERSIZED_VALUE, oversized.toString()); InetSocketAddress contactAddress = (InetSocketAddress) valueEntity.getCreator().getContactAddress(); networkingService.send(dht.getLocalNodeID().toHexString(), deleteMessage, contactAddress.getAddress().getHostAddress(), contactAddress.getPort() + 1); } private void getDhtNodesList() { if (isRunning()) { List<DhtNode> dhtNodes = dhtDiscovery.getDhtNodesList(); dhtNodes.remove(dhtSettings.getDhtNode()); for (DhtNode node : dhtNodes) { log.debug("Adding " + node + " as active node."); addActiveDhtNode(new InetSocketAddress(node.getHostAddress(), node.getPort())); } } } private void addActiveDhtNode(SocketAddress hostAddress) { if (!dht.isBootstrapped()) { log.info("Adding " + hostAddress + " to bootstrap hosts..."); bootstrapper.addBootstrapHost(hostAddress); } } private void put(KUID key, DHTValue value) { storageDaemon.store(new AllStorable(key, value)); } private void remove(KUID key) { storedKeys.remove(key.toHexString()); storageDaemon.store(new AllStorable(key, DHTValue.EMPTY_VALUE)); } private Set<DHTValueEntity> get(KUID key) { try { log.debug("Looking for key " + key + " in DHT..."); Set<DHTValueEntity> allLocalEntities = new HashSet<DHTValueEntity>(dht.getDatabase().get(key).values()); Set<DHTValueEntity> allEntities = new HashSet<DHTValueEntity>(allLocalEntities); FindValueResult result = dht.get(EntityKey.createEntityKey(key, DhtSettings.ALL_TYPE)).get(); allEntities.addAll(result.getEntities()); // Pull remaining values from the remote Node (if any) for (EntityKey entityKey : result.getEntityKeys()) { FindValueResult resultB = dht.get(entityKey).get(); allEntities.addAll(resultB.getEntities()); } return allEntities; } catch (Exception e) { log.error(e, e); } return Collections.emptySet(); } private DHTValue getLocalValue(KUID primaryKey) { Map<KUID, DHTValueEntity> localEntities = dht.getDatabase().get(primaryKey); for (DHTValueEntity valueEntity : localEntities.values()) { if (isLocalValue(valueEntity)) { return valueEntity.getValue(); } } return null; } private <T> T getDirectValue(KUID primaryKey, Class<T> clazz) { Map<KUID, DHTValueEntity> localEntities = dht.getDatabase().get(primaryKey); for (DHTValueEntity valueEntity : localEntities.values()) { if (valueEntity.isDirect()) { String json = new String(valueEntity.getValue().getValue()); return JsonConverter.toBean(json, clazz); } } return null; } private KUID createKUIDFromString(String keyStr) { byte[] sha1 = Digest.getSha1(keyStr.getBytes()); return sha1 != null ? KUID.createWithBytes(sha1) : null; } @SuppressWarnings("unchecked") private <T> T readDhtValue(DHTValue dhtValue, Class<T> clazz) { String json = new String(dhtValue.getValue()); if (Collection.class.isAssignableFrom(clazz)) { return (T) JsonConverter.toCollection(json, (Class<? extends Collection>) clazz); } else { return JsonConverter.toBean(json, clazz); } } private <T> DHTValue writeDhtValue(T value) { return writeDhtValue(JsonConverter.toJson(value).getBytes()); } private DHTValue writeDhtValue(byte[] value) { return new DHTValueImpl(DhtSettings.ALL_TYPE, Version.ZERO, value); } private boolean isLocalValue(DHTValueEntity entity) { return dht.getLocalNodeID().equals(entity.getCreator().getNodeID()); } public Set<InetAddress> getOwners(String primaryKey) { Set<? extends DHTValueEntity> entities = get(createKUIDFromString(primaryKey)); Set<InetAddress> owners = new HashSet<InetAddress>(); for (DHTValueEntity valueEntity : entities) { InetSocketAddress contactAddress = (InetSocketAddress) valueEntity.getCreator().getContactAddress(); owners.add(contactAddress.getAddress()); } return owners; } public boolean hasLocalValue(String primaryKey) { return getLocalValue(createKUIDFromString(primaryKey)) != null; } public void putOversizedValue(String primaryKey, Serializable oversizedValue) { String jsonValue = JsonConverter.toJson(oversizedValue); OversizedStorable storable = new OversizedStorable(createKUIDFromString(primaryKey), jsonValue.getBytes()); storedKeys.put(storable.getPrimaryKey().toHexString(), primaryKey); storageDaemon.store(storable); } private void putOversizedByRemoteNodeRequest(AllMessage<String> request) { log.info("Processing PUT_DHT_OVERSIZED_VALUE_REQUEST_TYPE for key : " + request.getProperty(DHT_PRIMARY_KEY)); try { String primaryKey = request.getProperty(DHT_PRIMARY_KEY); byte[] oversizedValue = request.getBody().getBytes(); byte[] sha1 = Digest.getSha1(oversizedValue); OversizedValueInfo valueInfo = getDirectValue(KUID.createWithHexString(primaryKey), OversizedValueInfo.class); if (Arrays.areEqual(valueInfo.getSha1(), sha1)) { dhtFileUtils.storeOnFileSystem(primaryKey, oversizedValue); } else { log.error("The oversized value in the request does not match with the info stored in its key."); } } catch (Exception e) { log.error(e, e); } } public <T> T getOversizedValue(String primaryKey, Class<T> clazz) { KUID dhtPrimaryKey = createKUIDFromString(primaryKey); byte[] jsonBytes = dhtFileUtils.readFromFileSystem(dhtPrimaryKey.toHexString()); if (jsonBytes == null) { log.info("Could not find oversized value for key " + primaryKey + " locally."); if (!oversizedValueRequests.contains(dhtPrimaryKey.toHexString())) { requestOversizedValue(dhtPrimaryKey); } waitForOversizedValueResponse(dhtPrimaryKey.toHexString()); jsonBytes = dhtFileUtils.readFromFileSystem(dhtPrimaryKey.toHexString()); } return jsonBytes == null ? null : JsonConverter.toBean(new String(jsonBytes), clazz); } private void requestOversizedValue(KUID primaryKey) { for (DHTValueEntity valueEntity : get(primaryKey)) { InetSocketAddress contactAddress = (InetSocketAddress) valueEntity.getSender().getContactAddress(); log.info("Will request oversized value to " + contactAddress.getAddress()); AllMessage<String> message = new AllMessage<String>(OVERSIZED_DHT_VALUE_REQUEST_TYPE, primaryKey.toHexString()); boolean requested = networkingService.send(dht.getLocalNodeID().toHexString(), message, contactAddress.getAddress().getHostAddress(), contactAddress.getPort() + 1); if (requested) { oversizedValueRequests.add(primaryKey.toHexString()); } break; } } private void waitForOversizedValueResponse(String oversizedValueKey) { long waitTime = 0L; try { while (oversizedValueRequests.contains(oversizedValueKey) && waitTime < dhtSettings.getOversizedValueRequestTimeout()) { Thread.sleep(DEFAULT_OVERSIZED_VALUE_AWAIT_TIME); waitTime += DEFAULT_OVERSIZED_VALUE_AWAIT_TIME; } } catch (Exception e) { log.error(e, e); } } private void processOversizedValueRequest(AllMessage<String> message) { String senderId = message.getProperty(MESSAGE_SENDER); if (senderId != null && !dht.getLocalNodeID().toHexString().equals(senderId)) { log.info("Processing OVERSIZED_DHT_VALUE_REQUEST_TYPE for key : " + message.getBody()); Contact sender = dht.getRouteTable().get(KUID.createWithHexString(senderId)); InetSocketAddress senderAddress = (InetSocketAddress) sender.getContactAddress(); byte[] oversizedValue = dhtFileUtils.readFromFileSystem(message.getBody()); if (oversizedValue != null) { AllMessage<String> response = new AllMessage<String>(OVERSIZED_DHT_VALUE_RESPONSE_TYPE, new String(oversizedValue)); response.putProperty(MESSAGE_SENDER, dht.getLocalNodeID().toHexString()); response.putProperty(DHT_PRIMARY_KEY, message.getBody()); networkingService.send(dht.getLocalNodeID().toHexString(), response, senderAddress.getAddress().getHostAddress(), senderAddress.getPort() + 1); } } } private void processOversizedValueResponse(AllMessage<String> message) { log.info("Processing OVERSIZED_DHT_VALUE_RESPONSE_TYPE for key : " + message.getProperty(DHT_PRIMARY_KEY)); String primaryKey = message.getProperty(DHT_PRIMARY_KEY); try { dhtFileUtils.storeOnFileSystem(primaryKey, message.getBody().getBytes()); oversizedValueRequests.remove(primaryKey); } catch (IOException e) { log.error(e, e); } } public void removeOversizedValue(String primaryKey) { KUID oversizedValueKey = createKUIDFromString(primaryKey); if (hasLocalValue(primaryKey)) { removeOversizedValue(oversizedValueKey); storedKeys.remove(primaryKey); } else { Set<DHTValueEntity> allEntities = get(oversizedValueKey); for (DHTValueEntity valueEntity : allEntities) { removeRemoteEntity(valueEntity, true); } } } private void removeOversizedValue(KUID oversizedValueKey) { storageDaemon.store(new OversizedStorable(oversizedValueKey)); } private void processDeleteDhtValueRemoteRequest(AllMessage<String> message) { String oversizedProp = message.getProperty(IS_OVERSIZED_VALUE); boolean oversized = oversizedProp != null ? Boolean.valueOf(oversizedProp) : false; KUID dhtKey = KUID.createWithHexString(message.getBody()); if (oversized) { removeOversizedValue(dhtKey); } else { remove(dhtKey); } } /* * MONITOR AND CONTROL METHODS */ public String more(String kuid) { Set<? extends DHTValueEntity> entities = get(KUID.createWithHexString(kuid)); if (entities != null && !entities.isEmpty()) { StringBuilder sb = new StringBuilder("\nDhtValueInfo:\n"); sb.append("Primary Key : "); sb.append(kuid); sb.append("\nBusiness Key : "); sb.append(storedKeys.get(kuid) != null ? storedKeys.get(kuid) : "Not Available"); sb.append("\nValues:\n\n"); for (DHTValueEntity valueEntity : entities) { sb.append("Value : "); Serializable value = null; try { value = new String(valueEntity.getValue().getValue()); } catch (Exception e) { value = "ERROR: Could not deserialize a value from dht"; } sb.append(value); sb.append("\nCreator :"); sb.append(valueEntity.getCreator().getContactAddress()); sb.append("\t"); sb.append(valueEntity.getCreator().getNodeID()); sb.append("\t"); sb.append(new Date(valueEntity.getCreationTime())); sb.append("\n\n"); } return sb.toString(); } else { return "Error: No Matching value found for key " + kuid; } } public Map<String, String> getLocalKeys() { HashMap<String, String> localKeys = new HashMap<String, String>(); for (DHTValueEntity entity : dht.getDatabase().values()) { if (isLocalValue(entity)) { String kuid = entity.getPrimaryKey().toHexString(); String value = storedKeys.get(kuid); localKeys.put(kuid, value != null ? value : "Not available"); } } return localKeys; } public Set<String> getAllKeys() { Set<String> allKeys = new TreeSet<String>(); for (KUID kuid : dht.getDatabase().keySet()) { allKeys.add(kuid.toHexString()); } return allKeys; } public String getNodeId() { return dht.getLocalNodeID().toHexString(); } }