Java tutorial
/* * Copyright 2014 Cask Data, Inc. * * 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 co.cask.cdap.client; import co.cask.cdap.api.annotation.Beta; import co.cask.cdap.api.service.Service; import co.cask.cdap.api.service.ServiceSpecification; import co.cask.cdap.api.service.http.HttpServiceHandlerSpecification; import co.cask.cdap.api.service.http.ServiceHttpEndpoint; import co.cask.cdap.client.config.ClientConfig; import co.cask.cdap.client.util.RESTClient; import co.cask.cdap.common.NotFoundException; import co.cask.cdap.common.UnauthorizedException; import co.cask.cdap.proto.Id; import co.cask.common.http.HttpMethod; import co.cask.common.http.HttpResponse; import co.cask.common.http.ObjectResponse; import com.google.common.collect.ImmutableList; import java.io.IOException; import java.net.HttpURLConnection; import java.net.URL; import java.util.List; import javax.inject.Inject; /** * Provides ways to interact with CDAP User Services. */ @Beta public class ServiceClient { private final RESTClient restClient; private final ClientConfig config; @Inject public ServiceClient(ClientConfig config, RESTClient restClient) { this.config = config; this.restClient = restClient; } public ServiceClient(ClientConfig config) { this.config = config; this.restClient = new RESTClient(config); } /** * Gets a {@link ServiceSpecification} for a {@link Service}. * * @param appId ID of the application that the service belongs to * @param serviceId ID of the service * @return {@link ServiceSpecification} representing the service * @throws IOException if a network error occurred * @throws UnauthorizedException if the request is not authorized successfully in the gateway server * @throws NotFoundException if the app or service could not be found * * @deprecated As of 3.1, use {@link #get(Id.Service)}. */ @Deprecated public ServiceSpecification get(String appId, String serviceId) throws IOException, UnauthorizedException, NotFoundException { return get(Id.Service.from(config.getNamespace(), appId, serviceId)); } /** * Gets a list of {@link ServiceHttpEndpoint} that a {@link Service} exposes * @param appId ID of the application that the service belongs to * @param serviceId ID of the service * @return A list of {@link ServiceHttpEndpoint} * @throws IOException if a network error occurred * @throws UnauthorizedException if the request is not authorized successfully in the gateway server * @throws NotFoundException if the app or service could not be found * * @deprecated As of 3.1, use {@link #getEndpoints(Id.Service)}. */ @Deprecated public List<ServiceHttpEndpoint> getEndpoints(String appId, String serviceId) throws IOException, UnauthorizedException, NotFoundException { return getEndpoints(Id.Service.from(config.getNamespace(), appId, serviceId)); } /** * @deprecated As of 3.1, use {@link #getServiceURL(Id.Service)}. */ @Deprecated public URL getServiceURL(String appId, String serviceId) throws NotFoundException, IOException, UnauthorizedException { return getServiceURL(Id.Service.from(config.getNamespace(), appId, serviceId)); } /** * Gets a {@link ServiceSpecification} for a {@link Service}. * * @param service ID of the service * @return {@link ServiceSpecification} representing the service * @throws IOException if a network error occurred * @throws UnauthorizedException if the request is not authorized successfully in the gateway server * @throws NotFoundException if the app or service could not be found */ public ServiceSpecification get(Id.Service service) throws IOException, UnauthorizedException, NotFoundException { URL url = config.resolveNamespacedURLV3(service.getNamespace(), String.format("apps/%s/services/%s", service.getApplicationId(), service.getId())); HttpResponse response = restClient.execute(HttpMethod.GET, url, config.getAccessToken(), HttpURLConnection.HTTP_NOT_FOUND); if (response.getResponseCode() == HttpURLConnection.HTTP_NOT_FOUND) { throw new NotFoundException(service); } return ObjectResponse.fromJsonBody(response, ServiceSpecification.class).getResponseObject(); } /** * Gets a list of {@link ServiceHttpEndpoint} that a {@link Service} exposes. * * @param service ID of the service * @return A list of {@link ServiceHttpEndpoint} * @throws IOException if a network error occurred * @throws UnauthorizedException if the request is not authorized successfully in the gateway server * @throws NotFoundException if the app or service could not be found */ public List<ServiceHttpEndpoint> getEndpoints(Id.Service service) throws IOException, UnauthorizedException, NotFoundException { ServiceSpecification specification = get(service); ImmutableList.Builder<ServiceHttpEndpoint> builder = new ImmutableList.Builder<>(); for (HttpServiceHandlerSpecification handlerSpecification : specification.getHandlers().values()) { builder.addAll(handlerSpecification.getEndpoints()); } return builder.build(); } public URL getServiceURL(Id.Service service) throws NotFoundException, IOException, UnauthorizedException { // Make sure the service actually exists get(service); return config.resolveNamespacedURLV3(service.getNamespace(), String.format("apps/%s/services/%s/methods/", service.getApplicationId(), service.getId())); } }