Java tutorial
/* * Copyright 2015 Google, Inc. All Rights Reserved. * * 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.examples.abelanav2; import com.google.api.client.googleapis.auth.oauth2.GoogleCredential; import com.google.api.client.googleapis.javanet.GoogleNetHttpTransport; import com.google.api.client.http.GenericUrl; import com.google.api.client.http.HttpRequest; import com.google.api.client.http.HttpRequestFactory; import com.google.api.client.http.HttpResponse; import com.google.api.client.http.HttpStatusCodes; import com.google.api.client.http.HttpTransport; import com.google.api.client.http.UrlEncodedContent; import java.io.IOException; import java.security.GeneralSecurityException; import java.util.Collections; import java.util.HashMap; import java.util.Map; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; /** * This class receives notifications from the GCS bucket, the Task Queue and the Image Resizer. */ public class TaskQueueNotificationServlet extends HttpServlet { @Override public final void doPost(final HttpServletRequest req, final HttpServletResponse resp) throws IOException { HttpTransport httpTransport; try { Map<Object, Object> params = new HashMap<>(); params.putAll(req.getParameterMap()); params.put("task", req.getHeader("X-AppEngine-TaskName")); httpTransport = GoogleNetHttpTransport.newTrustedTransport(); GoogleCredential credential = GoogleCredential.getApplicationDefault() .createScoped(Collections.singleton("https://www.googleapis.com/auth/userinfo.email")); HttpRequestFactory requestFactory = httpTransport.createRequestFactory(); GenericUrl url = new GenericUrl(ConfigurationConstants.IMAGE_RESIZER_URL); HttpRequest request = requestFactory.buildPostRequest(url, new UrlEncodedContent(params)); credential.initialize(request); HttpResponse response = request.execute(); if (!response.isSuccessStatusCode()) { log("Call to the imageresizer failed: " + response.getContent().toString()); resp.setStatus(HttpStatusCodes.STATUS_CODE_SERVER_ERROR); } else { resp.setStatus(response.getStatusCode()); } } catch (GeneralSecurityException | IOException e) { log("Http request error: " + e.getMessage()); resp.setStatus(HttpStatusCodes.STATUS_CODE_SERVER_ERROR); } } }