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* 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.jclouds.examples.rackspace.cloudqueues;
import com.google.common.collect.Lists;
import com.google.common.io.Closeables;
import org.jclouds.ContextBuilder;
import org.jclouds.openstack.marconi.v1.MarconiApi;
import org.jclouds.openstack.marconi.v1.domain.CreateMessage;
import org.jclouds.openstack.marconi.v1.domain.Message;
import org.jclouds.openstack.marconi.v1.domain.MessageStream;
import org.jclouds.openstack.marconi.v1.features.MessageApi;
import org.jclouds.openstack.marconi.v1.features.QueueApi;
import java.io.Closeable;
import java.io.IOException;
import java.io.StringReader;
import java.util.List;
import java.util.Properties;
import java.util.concurrent.ExecutionException;
import static java.lang.String.format;
import static org.jclouds.examples.rackspace.cloudqueues.Constants.CONSUMER_ID;
import static org.jclouds.examples.rackspace.cloudqueues.Constants.MESSAGE_NUM;
import static org.jclouds.examples.rackspace.cloudqueues.Constants.MESSAGE_TEXT;
import static org.jclouds.examples.rackspace.cloudqueues.Constants.NAME;
import static org.jclouds.examples.rackspace.cloudqueues.Constants.PRODUCER_ID;
import static org.jclouds.examples.rackspace.cloudqueues.Constants.PRODUCER_NAME;
import static org.jclouds.examples.rackspace.cloudqueues.Constants.PROVIDER;
import static org.jclouds.examples.rackspace.cloudqueues.Constants.PUBLISHER_ID;
import static org.jclouds.examples.rackspace.cloudqueues.Constants.ZONE;
import static org.jclouds.openstack.marconi.v1.options.StreamMessagesOptions.Builder.marker;
/**
* Stream messages off of a queue. In a very active queue it's possible that you could continuously stream messages
* indefinitely.
*
* You can also resume where you left off by remembering the marker.
*/
public class StreamMessages implements Closeable {
private final MarconiApi marconiApi;
private final QueueApi queueApi;
/**
* To get a username and API key see
* http://apache.jclouds.org/documentation/quickstart/rackspace/
*
* The first argument (args[0]) must be your username
* The second argument (args[1]) must be your API key
*/
public static void main(String[] args) throws IOException {
StreamMessages streamMessages = new StreamMessages(args[0], args[1]);
try {
streamMessages.createQueue();
streamMessages.createMessages();
streamMessages.streamMessages();
streamMessages.deleteQueue();
} catch (Exception e) {
e.printStackTrace();
} finally {
streamMessages.close();
}
}
public StreamMessages(String username, String apiKey) {
// If this application we're running *inside* the Rackspace Cloud, you would want to use the InternalUrlModule
// as below to have all of the Cloud Queues traffic go over the internal Rackspace Cloud network.
// Iterable<Module> modules = ImmutableSet.<Module> of(new InternalUrlModule());
marconiApi = ContextBuilder.newBuilder(PROVIDER)
.credentials(username, apiKey)
// .modules(modules)
.buildApi(MarconiApi.class);
queueApi = marconiApi.getQueueApiForZoneAndClient(ZONE, PUBLISHER_ID);
}
private void createQueue() {
queueApi.create(NAME);
}
private void createMessages() throws ExecutionException, InterruptedException {
System.out.format("Create Messages%n");
MessageApi messageApi = marconiApi.getMessageApiForZoneAndClientAndQueue(ZONE, PRODUCER_ID, NAME);
List<CreateMessage> createMessages = Lists.newArrayList();
for (int i=0; i < 10; i++) {
for (int j=0; j < 10; j++) {
StringBuilder bodyBuilder = new StringBuilder();
bodyBuilder.append(format("%s=%s%n", PRODUCER_NAME, PRODUCER_ID))
.append(format("%s=%d%n", MESSAGE_NUM, i*10+j))
.append(format("%s=%s%n", MESSAGE_TEXT, "Hear Ye! Hear Ye!"));
CreateMessage createMessage = CreateMessage.builder().ttl(300).body(bodyBuilder.toString()).build();
createMessages.add(createMessage);
}
messageApi.create(createMessages);
System.out.format(" Created %d messages%n", createMessages.size());
createMessages.clear();
}
}
private void streamMessages() {
System.out.format("Stream Messages%n");
MessageApi messageApi = marconiApi.getMessageApiForZoneAndClientAndQueue(ZONE, CONSUMER_ID, NAME);
MessageStream stream = messageApi.stream();
String marker = "";
while(stream.nextMarker().isPresent()) {
for (Message message: stream) {
Properties messageProps = loadStringProperties(message.getBody());
int messageNum = Integer.valueOf(messageProps.getProperty(MESSAGE_NUM));
System.out.format(" Read message %d%n", messageNum);
if (messageNum == 49) {
System.out.format(" Breaking at message %d%n", messageNum);
// Breaking here to illustrate how to resume using the marker below
break;
}
}
marker = stream.nextStreamOptions().getMarker();
stream = messageApi.stream(stream.nextStreamOptions());
}
stream = messageApi.stream(marker(marker));
while(stream.nextMarker().isPresent()) {
for (Message message: stream) {
Properties messageProps = loadStringProperties(message.getBody());
int messageNum = Integer.valueOf(messageProps.getProperty(MESSAGE_NUM));
System.out.format(" Read message %d%n", messageNum);
}
stream = messageApi.stream(stream.nextStreamOptions());
}
}
private void deleteQueue() {
queueApi.delete(NAME);
}
private Properties loadStringProperties(String body) {
Properties properties = new Properties();
try {
properties.load(new StringReader(body));
}
catch (IOException e) {
// IOException will never occur here because we're loading directly from a String
}
return properties;
}
/**
* Always close your service when you're done with it.
*
* Note that closing quietly like this is not necessary in Java 7.
* You would use try-with-resources in the main method instead.
*/
public void close() throws IOException {
Closeables.close(marconiApi, true);
}
}