Java tutorial
/** * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you 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 org.apache.hadoop.gateway.services.registry.impl; import com.fasterxml.jackson.core.JsonFactory; import com.fasterxml.jackson.core.JsonParseException; import com.fasterxml.jackson.core.JsonProcessingException; import com.fasterxml.jackson.core.type.TypeReference; import com.fasterxml.jackson.databind.JsonMappingException; import com.fasterxml.jackson.databind.ObjectMapper; import org.apache.commons.codec.binary.Base64; import org.apache.commons.io.FileUtils; import org.apache.hadoop.gateway.GatewayMessages; import org.apache.hadoop.gateway.config.GatewayConfig; import org.apache.hadoop.gateway.i18n.messages.MessagesFactory; import org.apache.hadoop.gateway.services.Service; import org.apache.hadoop.gateway.services.ServiceLifecycleException; import org.apache.hadoop.gateway.services.registry.ServiceRegistry; import org.apache.hadoop.gateway.services.security.CryptoService; import java.io.File; import java.io.IOException; import java.util.HashMap; import java.util.Map; import java.util.Random; public class DefaultServiceRegistryService implements ServiceRegistry, Service { private static GatewayMessages LOG = MessagesFactory.get(GatewayMessages.class); protected char[] chars = { 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'j', 'k', 'm', 'n', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'J', 'K', 'M', 'N', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', '2', '3', '4', '5', '6', '7', '8', '9', }; private CryptoService crypto; private Registry registry = new Registry(); private String registryFileName; public DefaultServiceRegistryService() { } public void setCryptoService(CryptoService crypto) { this.crypto = crypto; } public String getRegistrationCode(String clusterName) { String code = generateRegCode(16); byte[] signature = crypto.sign("SHA256withRSA", "gateway-identity", code); String encodedSig = Base64.encodeBase64URLSafeString(signature); return code + "::" + encodedSig; } private String generateRegCode(int length) { StringBuffer sb = new StringBuffer(); Random r = new Random(); for (int i = 0; i < length; i++) { sb.append(chars[r.nextInt(chars.length)]); } return sb.toString(); } public void removeClusterServices(String clusterName) { registry.remove(clusterName); } public boolean registerService(String regCode, String clusterName, String serviceName, String url) { boolean rc = false; // verify the signature of the regCode if (regCode == null) { throw new IllegalArgumentException("Registration Code must not be null."); } String[] parts = regCode.split("::"); // part one is the code and part two is the signature boolean verified = crypto.verify("SHA256withRSA", "gateway-identity", parts[0], Base64.decodeBase64(parts[1])); if (verified) { HashMap<String, RegEntry> clusterServices = registry.get(clusterName); if (clusterServices == null) { synchronized (this) { clusterServices = new HashMap<String, RegEntry>(); registry.put(clusterName, clusterServices); } } RegEntry regEntry = new RegEntry(); regEntry.setClusterName(clusterName); regEntry.setServiceName(serviceName); regEntry.setUrl(url); clusterServices.put(serviceName, regEntry); String json = renderAsJsonString(registry); try { FileUtils.write(new File(registryFileName), json); rc = true; } catch (IOException e) { // log appropriately e.printStackTrace(); //TODO: I18N } } return rc; } private String renderAsJsonString(HashMap<String, HashMap<String, RegEntry>> registry) { String json = null; ObjectMapper mapper = new ObjectMapper(); try { // write JSON to a file json = mapper.writeValueAsString((Object) registry); } catch (JsonProcessingException e) { e.printStackTrace(); //TODO: I18N } return json; } public String lookupServiceURL(String clusterName, String serviceName) { String url = null; RegEntry entry = null; HashMap clusterServices = registry.get(clusterName); if (clusterServices != null) { entry = (RegEntry) clusterServices.get(serviceName); if (entry != null) { url = entry.url; } } return url; } private HashMap<String, HashMap<String, RegEntry>> getMapFromJsonString(String json) { Registry map = null; JsonFactory factory = new JsonFactory(); ObjectMapper mapper = new ObjectMapper(factory); TypeReference<Registry> typeRef = new TypeReference<Registry>() { }; try { map = mapper.readValue(json, typeRef); } catch (JsonParseException e) { LOG.failedToGetMapFromJsonString(json, e); } catch (JsonMappingException e) { LOG.failedToGetMapFromJsonString(json, e); } catch (IOException e) { LOG.failedToGetMapFromJsonString(json, e); } return map; } @Override public void init(GatewayConfig config, Map<String, String> options) throws ServiceLifecycleException { String securityDir = config.getGatewaySecurityDir(); String filename = "registry"; setupRegistryFile(securityDir, filename); } protected void setupRegistryFile(String securityDir, String filename) throws ServiceLifecycleException { File registryFile = new File(securityDir, filename); if (registryFile.exists()) { try { String json = FileUtils.readFileToString(registryFile); registry = (Registry) getMapFromJsonString(json); } catch (Exception e) { throw new ServiceLifecycleException("Unable to load the persisted registry.", e); } } registryFileName = registryFile.getAbsolutePath(); } @Override public void start() throws ServiceLifecycleException { } @Override public void stop() throws ServiceLifecycleException { } }