Java tutorial
// Copyright (c) Microsoft. All rights reserved. // Licensed under the MIT license. See LICENSE file in the project root for full license information. package com.microsoft.azure.servicebus.samples.topicsgettingstarted; import com.google.gson.reflect.TypeToken; import com.microsoft.azure.servicebus.*; import com.microsoft.azure.servicebus.primitives.ConnectionStringBuilder; import com.google.gson.Gson; import static java.nio.charset.StandardCharsets.*; import java.time.Duration; import java.util.*; import java.util.concurrent.*; import java.util.function.Function; import org.apache.commons.cli.*; public class TopicsGettingStarted { static final Gson GSON = new Gson(); public void run(String connectionString) throws Exception { TopicClient sendClient; SubscriptionClient subscription1Client; SubscriptionClient subscription2Client; SubscriptionClient subscription3Client; // Create a QueueClient instance using the connection string builder // We set the receive mode to "PeekLock", meaning the message is delivered // under a lock and must be acknowledged ("completed") to be removed from the queue subscription1Client = new SubscriptionClient( new ConnectionStringBuilder(connectionString, "BasicTopic/subscriptions/Subscription1"), ReceiveMode.PEEKLOCK); subscription2Client = new SubscriptionClient( new ConnectionStringBuilder(connectionString, "BasicTopic/subscriptions/Subscription2"), ReceiveMode.PEEKLOCK); subscription3Client = new SubscriptionClient( new ConnectionStringBuilder(connectionString, "BasicTopic/subscriptions/Subscription3"), ReceiveMode.PEEKLOCK); ExecutorService executorService = Executors.newCachedThreadPool(); registerMessageHandlerOnClient(subscription1Client, executorService); registerMessageHandlerOnClient(subscription2Client, executorService); registerMessageHandlerOnClient(subscription3Client, executorService); sendClient = new TopicClient(new ConnectionStringBuilder(connectionString, "BasicTopic")); sendMessagesAsync(sendClient).thenRunAsync(() -> sendClient.closeAsync()); // wait for ENTER or 10 seconds elapsing waitForEnter(10); CompletableFuture.allOf(subscription1Client.closeAsync(), subscription2Client.closeAsync(), subscription3Client.closeAsync()).join(); executorService.shutdown(); } CompletableFuture<Void> sendMessagesAsync(TopicClient sendClient) { List<HashMap<String, String>> data = GSON.fromJson("[" + "{'name' = 'Einstein', 'firstName' = 'Albert'}," + "{'name' = 'Heisenberg', 'firstName' = 'Werner'}," + "{'name' = 'Curie', 'firstName' = 'Marie'}," + "{'name' = 'Hawking', 'firstName' = 'Steven'}," + "{'name' = 'Newton', 'firstName' = 'Isaac'}," + "{'name' = 'Bohr', 'firstName' = 'Niels'}," + "{'name' = 'Faraday', 'firstName' = 'Michael'}," + "{'name' = 'Galilei', 'firstName' = 'Galileo'}," + "{'name' = 'Kepler', 'firstName' = 'Johannes'}," + "{'name' = 'Kopernikus', 'firstName' = 'Nikolaus'}" + "]", new TypeToken<List<HashMap<String, String>>>() { }.getType()); List<CompletableFuture> tasks = new ArrayList<>(); for (int i = 0; i < data.size(); i++) { final String messageId = Integer.toString(i); Message message = new Message(GSON.toJson(data.get(i), Map.class).getBytes(UTF_8)); message.setContentType("application/json"); message.setLabel("Scientist"); message.setMessageId(messageId); message.setTimeToLive(Duration.ofMinutes(2)); System.out.printf("Message sending: Id = %s\n", message.getMessageId()); tasks.add(sendClient.sendAsync(message).thenRunAsync(() -> { System.out.printf("\tMessage acknowledged: Id = %s\n", message.getMessageId()); })); } return CompletableFuture.allOf(tasks.toArray(new CompletableFuture<?>[tasks.size()])); } void registerMessageHandlerOnClient(SubscriptionClient receiveClient, ExecutorService executorService) throws Exception { // register the RegisterMessageHandler callback receiveClient.registerMessageHandler(new IMessageHandler() { // callback invoked when the message handler loop has obtained a message public CompletableFuture<Void> onMessageAsync(IMessage message) { // receives message is passed to callback if (message.getLabel() != null && message.getContentType() != null && message.getLabel().contentEquals("Scientist") && message.getContentType().contentEquals("application/json")) { byte[] body = message.getBody(); Map scientist = GSON.fromJson(new String(body, UTF_8), Map.class); System.out.printf( "\n\t\t\t\t%s Message received: \n\t\t\t\t\t\tMessageId = %s, \n\t\t\t\t\t\tSequenceNumber = %s, \n\t\t\t\t\t\tEnqueuedTimeUtc = %s," + "\n\t\t\t\t\t\tExpiresAtUtc = %s, \n\t\t\t\t\t\tContentType = \"%s\", \n\t\t\t\t\t\tContent: [ firstName = %s, name = %s ]\n", receiveClient.getEntityPath(), message.getMessageId(), message.getSequenceNumber(), message.getEnqueuedTimeUtc(), message.getExpiresAtUtc(), message.getContentType(), scientist != null ? scientist.get("firstName") : "", scientist != null ? scientist.get("name") : ""); } return receiveClient.completeAsync(message.getLockToken()); } // callback invoked when the message handler has an exception to report public void notifyException(Throwable throwable, ExceptionPhase exceptionPhase) { System.out.printf(exceptionPhase + "-" + throwable.getMessage()); } }, // 1 concurrent call, messages are auto-completed, auto-renew duration new MessageHandlerOptions(1, false, Duration.ofMinutes(1)), executorService); } public static void main(String[] args) { System.exit(runApp(args, (connectionString) -> { TopicsGettingStarted app = new TopicsGettingStarted(); try { app.run(connectionString); return 0; } catch (Exception e) { System.out.printf("%s", e.toString()); return 1; } })); } static final String SB_SAMPLES_CONNECTIONSTRING = "SB_SAMPLES_CONNECTIONSTRING"; public static int runApp(String[] args, Function<String, Integer> run) { try { String connectionString = null; // parse connection string from command line Options options = new Options(); options.addOption(new Option("c", true, "Connection string")); CommandLineParser clp = new DefaultParser(); CommandLine cl = clp.parse(options, args); if (cl.getOptionValue("c") != null) { connectionString = cl.getOptionValue("c"); } // get overrides from the environment String env = System.getenv(SB_SAMPLES_CONNECTIONSTRING); if (env != null) { connectionString = env; } if (connectionString == null) { HelpFormatter formatter = new HelpFormatter(); formatter.printHelp("run jar with", "", options, "", true); return 2; } return run.apply(connectionString); } catch (Exception e) { System.out.printf("%s", e.toString()); return 3; } } private void waitForEnter(int seconds) { ExecutorService executor = Executors.newCachedThreadPool(); try { executor.invokeAny(Arrays.asList(() -> { System.in.read(); return 0; }, () -> { Thread.sleep(seconds * 1000); return 0; })); } catch (Exception e) { // absorb } } }