I started JMS for a week now. I created JMS using Netbeans,maven and glassfish.
I have one producer and one durable consumer and I wanted to add another durable consumer to the same topic(not queue). Is it possible to do so?
because I want all the consumers consume all the message being sent by the producer whether the consumers are offline or not.
Any advice?
Thanks
public class DurableReceive {
#Resource(lookup = "jms/myDurableConnectionFactory")
private static ConnectionFactory connectionFactory;
#Resource(lookup = "jms/myNewTopic")
private static Topic topic;
public static void main(String[] args) {
Destination dest = (Destination) topic;
JMSConsumer consumer;
boolean messageReceived = false;
String message;
System.out.println("Waiting for messages...");
try (JMSContext context = connectionFactory.createContext();) {
consumer = context.createDurableConsumer(topic, "Subscriber1");
while (!messageReceived) {
message = consumer.receiveBody(String.class);
if (message != null) {
System.out.print("Received the following message: " + message);
System.out.println("(Received date: " + new Date() + ")\n");
} else {
messageReceived = true;
}
}
} catch (JMSRuntimeException e) {
System.err.println("##$%RuntimeException occurred: " + e.toString());
System.exit(1);
}
}
}
You can set different clientID for different durable consumers. Jms-broker uses combination of subscriptionName and clientId to identify the unique client (so if your subscriber have unique clientID - it can receive own messages). You can set clientID in your JmsContext.
Related
I'm am using Virtual Destinations to implement Publish Subscribe model in ActiveMQ 5.15.13.
I have a virtual topic VirtualTopic and there are two queues bound to it. Each queue has its own redelivery policy. Let's say Queue 1 will retry message 2 times in case there is an exception while processing the message and Queue 2 will retry message 3 times. Post retry message will be sent to deadletter queue. I'm also using Individual Dead letter Queue strategy so that each queue has it's own deadletter queue.
I've observed that when a message is sent to VirtualTopic, the message with same message id is delivered to both the queues. I'm facing an issue where if the consumers of both queues are not able to process the message successfully. The message destined for Queue 1 is moved to deadletter queue after retrying for 2 times. But there is no deadletter queue for Queue 2, though message in Queue 2 is retried for 3 times.
Is it the expected behavior?
Code:
public class ActiveMQRedelivery {
private final ActiveMQConnectionFactory factory;
public ActiveMQRedelivery(String brokerUrl) {
factory = new ActiveMQConnectionFactory(brokerUrl);
factory.setUserName("admin");
factory.setPassword("password");
factory.setAlwaysSyncSend(false);
}
public void publish(String topicAddress, String message) {
final String topicName = "VirtualTopic." + topicAddress;
try {
final Connection producerConnection = factory.createConnection();
producerConnection.start();
final Session producerSession = producerConnection.createSession(false, AUTO_ACKNOWLEDGE);
final MessageProducer producer = producerSession.createProducer(null);
final TextMessage textMessage = producerSession.createTextMessage(message);
final Topic topic = producerSession.createTopic(topicName);
producer.send(topic, textMessage, PERSISTENT, DEFAULT_PRIORITY, DEFAULT_TIME_TO_LIVE);
} catch (JMSException e) {
throw new RuntimeException("Message could not be published", e);
}
}
public void initializeConsumer(String queueName, String topicAddress, int numOfRetry) throws JMSException {
factory.getRedeliveryPolicyMap().put(new ActiveMQQueue("*." + queueName + ".>"),
getRedeliveryPolicy(numOfRetry));
Connection connection = factory.createConnection();
connection.start();
final Session consumerSession = connection.createSession(false, CLIENT_ACKNOWLEDGE);
final Queue queue = consumerSession.createQueue("Consumer." + queueName +
".VirtualTopic." + topicAddress);
final MessageConsumer consumer = consumerSession.createConsumer(queue);
consumer.setMessageListener(message -> {
try {
System.out.println("in listener --- " + ((ActiveMQDestination)message.getJMSDestination()).getPhysicalName());
consumerSession.recover();
} catch (JMSException e) {
e.printStackTrace();
}
});
}
private RedeliveryPolicy getRedeliveryPolicy(int numOfRetry) {
final RedeliveryPolicy redeliveryPolicy = new RedeliveryPolicy();
redeliveryPolicy.setInitialRedeliveryDelay(0);
redeliveryPolicy.setMaximumRedeliveries(numOfRetry);
redeliveryPolicy.setMaximumRedeliveryDelay(-1);
redeliveryPolicy.setRedeliveryDelay(0);
return redeliveryPolicy;
}
}
Test:
public class ActiveMQRedeliveryTest {
private static final String brokerUrl = "tcp://0.0.0.0:61616";
private ActiveMQRedelivery activeMQRedelivery;
#Before
public void setUp() throws Exception {
activeMQRedelivery = new ActiveMQRedelivery(brokerUrl);
}
#Test
public void testMessageRedeliveries() throws Exception {
String topicAddress = "testTopic";
activeMQRedelivery.initializeConsumer("queue1", topicAddress, 2);
activeMQRedelivery.initializeConsumer("queue2", topicAddress, 3);
activeMQRedelivery.publish(topicAddress, "TestMessage");
Thread.sleep(3000);
}
#After
public void tearDown() throws Exception {
}
}
I recently came across this problem. To fix this there are 2 attributes that needs to be added to individualDeadLetterStrategy as below
<deadLetterStrategy>
<individualDeadLetterStrategy destinationPerDurableSubscriber="true" enableAudit="false" queuePrefix="DLQ." useQueueForQueueMessages="true"/>
</deadLetterStrategy>
Explanation of attributes:
destinationPerDurableSubscriber - To enable a separate destination per durable subscriber.
enableAudit - The dead letter strategy has a message audit that is enabled by default. This prevents duplicate messages from being added to the configured DLQ. When the attribute is enabled, the same message that isn't delivered for multiple subscribers to a topic will only be placed on one of the subscriber DLQs when the destinationPerDurableSubscriber attribute is set to true i.e. say two consumers fail to acknowledge the same message for the topic, that message will only be placed on the DLQ for one consumer and not the other.
I've used the subscriber example from the google documentation for Google PubSub
the only modification I've made is commenting out the acknowledgement of the messages.
The subscriber doesn't add messages to the queue anymore while messages should be resent according to the interval set in the google cloud console.
Why is this happening or am I missing something?
public class SubscriberExample {
use the default project id
private static final String PROJECT_ID = ServiceOptions.getDefaultProjectId();
private static final BlockingQueue<PubsubMessage> messages = new LinkedBlockingDeque<>();
static class MessageReceiverExample implements MessageReceiver {
#Override
public void receiveMessage(PubsubMessage message, AckReplyConsumer consumer) {
messages.offer(message);
//consumer.ack();
}
}
/** Receive messages over a subscription. */
public static void main(String[] args) throws Exception {
// set subscriber id, eg. my-sub
String subscriptionId = args[0];
ProjectSubscriptionName subscriptionName = ProjectSubscriptionName.of(
PROJECT_ID, subscriptionId);
Subscriber subscriber = null;
try {
// create a subscriber bound to the asynchronous message receiver
subscriber = Subscriber.newBuilder(subscriptionName, new MessageReceiverExample()).build();
subscriber.startAsync().awaitRunning();
// Continue to listen to messages
while (true) {
PubsubMessage message = messages.take();
System.out.println("Message Id: " + message.getMessageId());
System.out.println("Data: " + message.getData().toStringUtf8());
}
} finally {
if (subscriber != null) {
subscriber.stopAsync();
}
}
}
}
When you do not acknowledge a messages, the Java client library calls modifyAckDeadline on the message until maxAckExtensionPeriod passes. By default, this value is one hour. Therefore, if you don't ack/nack the message or change this value, it is likely the message will not be redelivered for an hour. If you want to change the max ack extension period, set it on the builder:
subscriber = Subscriber.newBuilder(subscriptionName, new MessageReceiverExample())
.setMaxAckExtensionPeriod(Duration.ofSeconds(60))
.build();
It is also worth noting that when you don't ack or nack messages, then flow control may prevent the delivery of more messages. By default, the Java client library allows up to 1000 messages to be outstanding, i.e., waiting for ack or nack or for the max ack extension period to pass.
I am implementing MQTT Client with Eclipse Paho and has some problems:
Both Publisher and Subscriber connect to broker with qos = 1 and setCleanSession =
false.
My flow:
Connect Subscriber and Publisher to broker, it's ok.
Disconnect Subscriber (I force stop My Project which include Subscriber ), Publisher continuing publishing message.
Reconnect Subscriber -> it cannot connect and throw exception: connectionLost.
If i set qos of Subscriber = 0, it not throw exception but The client does not receive messages sent by the publisher while the subscriber is offline, which I do not want
Can someone help me with this?
This is my code in subcriber
try {
// Create an Mqtt client
MqttAsyncClient mqttClient
= new MqttAsyncClient("tcp://" + swmConfig.getMqttApiLink(), "MeasureTransactionApi");
// new MqttAsyncClient(serverURI, clientId, persistence)
MqttConnectOptions connOpts = new MqttConnectOptions();
connOpts.setUserName(swmConfig.getMqttUsername());
connOpts.setPassword(swmConfig.getMqttPassword().toCharArray());
connOpts.setCleanSession(false);
// Connect to RabbitMQ Broker
log.info("Connecting to RabbitMQ broker: " + swmConfig.getMqttApiLink());
IMqttToken conToken = mqttClient.connect(connOpts);
conToken.waitForCompletion(10000);
if (!conToken.isComplete() || conToken.getException() != null) {
log.info("Error connecting: " + conToken.getException());
System.exit(-1);
}
log.info("Connected");
// Latch used for synchronizing b/w threads
final CountDownLatch latch = new CountDownLatch(1);
// Callback - Anonymous inner-class for receiving messages
mqttClient.setCallback(new MqttCallback() {
public void messageArrived(String topic, MqttMessage message) {
String time = new Timestamp(System.currentTimeMillis()).toString();
log.info("\nReceived a Message from RabbitMQ Broker" + "\n\tTime: " + time
+ "\n\tTopic: " + topic + "\n\tMessage: "
+ new String(message.getPayload()) + "\n\tQoS: "
+ message.getQos() + "\n");
handleMQTTMessageService.handleMessageArrived(message);
}
public void connectionLost(Throwable cause) {
log.info("Connection to RabbitMQ broker lost!" + cause.getMessage());
latch.countDown();
}
public void deliveryComplete(IMqttDeliveryToken token) {
log.info("deliveryComplete");
}
});
// Subscribe client to the topic filter with QoS level of 1
log.info("Subscribing client to topic: " + topic);
IMqttToken subToken = mqttClient.subscribe(topic, 1);
subToken.waitForCompletion(10000);
if (!subToken.isComplete() || subToken.getException() != null) {
log.info("Error subscribing: " + subToken.getException());
System.exit(-1);
}
} catch (MqttException me) {
log.error("Error:", me);
}
QOS is independent for publishers and subscribers.
To ensure delivery to the subscribing client you need to subscribe at greater than QOS 0.
What happens to QOS 0 subscriptions depends on the broker, by default most will not queue messages for QOS 0 subscriptions, but mosquitto can be forced to with the queue_qos0_messages configuration flag
I want to process all the messages from a JMS Queue in Glassfish 3 in a synchronous way so I have tried to change the property Maximum Active Consumers from -1 to 1 in JMS Physical Destination in Glassfish window. I think setting this I will have only one Consumer executing OnMessage() at the same time. The problem I have reached its that when I change that property I got this error:
[I500]: Caught JVM Exception: org.xml.sax.SAXParseException: Content is not allowed in prolog.
[I500]: Caught JVM Exception: com.sun.messaging.jms.JMSException: Content is not allowed in prolog.
sendMessage Error [C4038]: com.sun.messaging.jms.JMSException: Content is not allowed in prolog.
If anyone know another way to make the method onmessage() synchronous will be appreciated. This is my Consumer Class:
#MessageDriven(mappedName = "QueueListener", activationConfig = {
#ActivationConfigProperty(propertyName = "acknowledgeMode", propertyValue = "Auto-acknowledge"),
#ActivationConfigProperty(propertyName = "destinationType", propertyValue = "javax.jms.Queue")
})
public class MessageBean implements MessageListener {
#Override
public void onMessage(Message message) {
long t1 = System.currentTimeMillis();
write("MessageBean has received " + message);
try{
TextMessage result=(TextMessage)message;
String text=result.getText();
write("OTAMessageBean message ID has resolved to " + text);
int messageID=Integer.valueOf(text);
AirProcessing aP=new AirProcessing();
aP.pickup(messageID);
}
catch(Exception e){
raiseError("OTAMessageBean error " + e.getMessage());
}
long t2 = System.currentTimeMillis();
write("MessageBean has finished in " + (t2-t1));
}
}
I had the same problem, the only solution I found was to set up a Schedule which polls the messages from the queue every ten seconds:
#Stateless
public class MyReceiver {
#Resource(mappedName = "jms/MyQueueFactory")
private QueueConnectionFactory connectionFactory;
#Resource(mappedName = "jms/MyQueue")
private Queue myQueue;
private QueueConnection qc;
private QueueSession session;
private MessageConsumer consumer;
#PostConstruct
void init() {
try {
qc = connectionFactory.createQueueConnection();
session = qc.createQueueSession(false, Session.CLIENT_ACKNOWLEDGE);
consumer = session.createConsumer(myQueue);
qc.start();
} catch (JMSException e) {
throw new RuntimeException(e);
}
}
#PreDestroy
void cleanup() throws JMSException {
qc.close();
}
#Schedule(hour = "*", minute = "*", second = "*/10", persistent = false)
public void onMessage() throws JMSException {
Message message;
while ((message = consumer.receiveNoWait()) != null) {
ObjectMessage objMsg = (ObjectMessage) message;
Serializable content;
try {
content = objMsg.getObject();
//Do sth. with "content" here
message.acknowledge();
} catch (JMSException ex) {
ex.printStackTrace();
}
}
}
}
JMS is async by nature, you don't have a specific config for telling io to behave synchronously. You can simulate it by adding message delivery and consumption confirmations everywhere, but that's not really how JMS is intended to work. Try RMIenter link description here or maybe HTTP (or something on top of it like a SOAP or REST web service)
There are two programs: subscriber and publisher...
Subscriber is able to put the message onto the topic and the message is sent successfully.
When I check the activemq server on my browser it shows 1 msg enqueued . But when I run the consumer code, it is not receiving the message
Here is the producer code:
import javax.jms.*;
import org.apache.activemq.ActiveMQConnection;
import org.apache.activemq.ActiveMQConnectionFactory;
public class producer {
private static String url = ActiveMQConnection.DEFAULT_BROKER_URL;
public static void main(String[] args) throws JMSException {
ConnectionFactory connectionFactory = new ActiveMQConnectionFactory(url);
Connection connection = connectionFactory.createConnection();
connection.start();
// JMS messages are sent and received using a Session. We will
// create here a non-transactional session object. If you want
// to use transactions you should set the first parameter to 'true'
Session session = connection.createSession(false,
Session.AUTO_ACKNOWLEDGE);
Topic topic = session.createTopic("testt");
MessageProducer producer = session.createProducer(topic);
// We will send a small text message saying 'Hello'
TextMessage message = session.createTextMessage();
message.setText("HELLO JMS WORLD");
// Here we are sending the message!
producer.send(message);
System.out.println("Sent message '" + message.getText() + "'");
connection.close();
}
}
After I run this code the output at the console is:
26 Jan, 2012 2:30:04 PM org.apache.activemq.transport.failover.FailoverTransport doReconnect
INFO: Successfully connected to tcp://localhost:61616
Sent message 'HELLO JMS WORLD'
And here is the consumer code:
import javax.jms.*;
import org.apache.activemq.ActiveMQConnection;
import org.apache.activemq.ActiveMQConnectionFactory;
public class consumer {
// URL of the JMS server
private static String url = ActiveMQConnection.DEFAULT_BROKER_URL;
// Name of the topic from which we will receive messages from = " testt"
public static void main(String[] args) throws JMSException {
// Getting JMS connection from the server
ConnectionFactory connectionFactory = new ActiveMQConnectionFactory(url);
Connection connection = connectionFactory.createConnection();
connection.start();
Session session = connection.createSession(false,
Session.AUTO_ACKNOWLEDGE);
Topic topic = session.createTopic("testt");
MessageConsumer consumer = session.createConsumer(topic);
MessageListener listner = new MessageListener() {
public void onMessage(Message message) {
try {
if (message instanceof TextMessage) {
TextMessage textMessage = (TextMessage) message;
System.out.println("Received message"
+ textMessage.getText() + "'");
}
} catch (JMSException e) {
System.out.println("Caught:" + e);
e.printStackTrace();
}
}
};
consumer.setMessageListener(listner);
connection.close();
}
}
After I run this code it doesnt show anything.
Can someone help to me to overcome this problem?
Your issue is that your consumer is running and then shutting down immediately.
Try adding this into your consumer:
consumer.setMessageListener(listner);
try {
System.in.read();
} catch (IOException e) {
e.printStackTrace();
}
connection.close();
This will wait until you hit a key before stopping.
Other things to consider:
Use a finally block for the close
Java naming conventions encourage using uppercase for the first letter of a class
The main problem (besides the app closing down to quickly) is that you are sending to a Topic. Topics don't retain messages so if you run your application that produces and then run the consumer, the consumer won't receive anything because it was not subscribed to the topic at the time the message was sent. If you fix the shutdown issue and then run the consumer in one terminal and then run the producer you should then see the message received by your consumer. If you want message retention then you need to use a Queue which will hold onto the message until someone consumes it.
Your producer class is correct. It runs smoothly.
But, your consumer is incorrect & you have to modify it.
First, add setClientID("any_string_value") after creating connection object;
eg: Connection connection = connectionFactory.createConnection();
// need to setClientID value, any string value you wish
connection.setClientID("12345");
secondly, use createDurableSubscriber() method instead of createConsumer() for transmitting message via topic.
MessageConsumer consumer = session.createDurableSubscriber(topic,"SUB1234");
Here is the modified comsumer class:
package mq.test;
import javax.jms.*;
import org.apache.activemq.ActiveMQConnection;
import org.apache.activemq.ActiveMQConnectionFactory;
public class consumer {
// URL of the JMS server
private static String url = ActiveMQConnection.DEFAULT_BROKER_URL;
// Name of the topic from which we will receive messages from = " testt"
public static void main(String[] args) throws JMSException {
// Getting JMS connection from the server
ConnectionFactory connectionFactory = new ActiveMQConnectionFactory(url);
Connection connection = connectionFactory.createConnection();
// need to setClientID value, any string value you wish
connection.setClientID("12345");
try{
connection.start();
}catch(Exception e){
System.err.println("NOT CONNECTED!!!");
}
Session session = connection.createSession(false,
Session.AUTO_ACKNOWLEDGE);
Topic topic = session.createTopic("test_data");
//need to use createDurableSubscriber() method instead of createConsumer() for topic
// MessageConsumer consumer = session.createConsumer(topic);
MessageConsumer consumer = session.createDurableSubscriber(topic,
"SUB1234");
MessageListener listner = new MessageListener() {
public void onMessage(Message message) {
try {
if (message instanceof TextMessage) {
TextMessage textMessage = (TextMessage) message;
System.out.println("Received message"
+ textMessage.getText() + "'");
}
} catch (JMSException e) {
System.out.println("Caught:" + e);
e.printStackTrace();
}
}
};
consumer.setMessageListener(listner);
//connection.close();
}
}
Now, your code will run successfully.
just some:
work with a queue not a topic. messages in topics will be discarded when no consumer is available, they are NOT persistend.
add connection.start() after setting the message listener. you should start a connection when all consumers/producers are properly set up.
wait some time before before closing the connection again.
the topic will probably be your most important source of failure.