I have a single threaded ActiveMQ consumer written in Java. All I'm trying to do is receive() a messsage from the queue, attempt to send it to a web service, and if it succeeds acknowledge() it. If the web service call fails, I want the message to stay on the queue and be resent after some timeout.
It's more or less working, except for the resending part: each time I restart my consumer, it gets one message for each that's still on the queue, but after failing to send them, the messages are never resent.
My code looks like:
public boolean init() throws JMSException, FileNotFoundException, IOException {
ActiveMQConnectionFactory connectionFactory = new ActiveMQConnectionFactory(user, password, url);
RedeliveryPolicy policy = new RedeliveryPolicy();
policy.setInitialRedeliveryDelay(500);
policy.setBackOffMultiplier(2);
policy.setUseExponentialBackOff(true);
connectionFactory.setRedeliveryPolicy(policy);
connectionFactory.setUseRetroactiveConsumer(true); // ????
Connection connection = connectionFactory.createConnection();
connection.setExceptionListener(this);
connection.start();
session = connection.createSession(transacted, ActiveMQSession.INDIVIDUAL_ACKNOWLEDGE);
destination = session.createQueue(subject); //???
consumer = session.createConsumer(destination);
//consumer.setMessageListener(this); // message listener had same behaviour
}
private void process() {
while(true) {
System.out.println("Waiting...");
try {
Message message = consumer.receive();
onMessage(message);
} catch (JMSException e) {
e.printStackTrace();
}
try {
Thread.sleep(500);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
#Override
public void onMessage(Message message) {
System.out.println("onMessage");
messagesReceived++;
if (message instanceof TextMessage) {
try {
TextMessage txtMsg = (TextMessage) message;
String msg = txtMsg.getText();
if(!client.sendMessage(msg)) {
System.out.println("Webservice call failed. Keeping message");
//message.
} else {
message.acknowledge();
}
if (transacted) {
if ((messagesReceived % batch) == 0) {
System.out.println("Commiting transaction for last " + batch + " messages; messages so far = " + messagesReceived);
session.commit();
}
}
} catch (JMSException e) {
e.printStackTrace();
}
}
}
I'm not currently using transactions (maybe I should be?).
I'm sure I'm missing something easy and will be slapping my forehead soon but I can't seem to figure out how this is supposed to work. Thanks!
EDIT: Can't answer this myself as not enough rep:
OK, after some more experimentation, it turns out transactions are the only way to do this. Here is the new code:
public boolean init() throws JMSException, FileNotFoundException, IOException {
ActiveMQConnectionFactory connectionFactory = new ActiveMQConnectionFactory(user, password, url);
RedeliveryPolicy policy = new RedeliveryPolicy();
policy.setInitialRedeliveryDelay(1000L);
policy.setMaximumRedeliveries(RedeliveryPolicy.NO_MAXIMUM_REDELIVERIES);
connectionFactory.setRedeliveryPolicy(policy);
connectionFactory.setUseRetroactiveConsumer(true);
Connection connection = connectionFactory.createConnection();
connection.setExceptionListener(this);
connection.start();
session = connection.createSession(transacted, ActiveMQSession.CLIENT_ACKNOWLEDGE);
destination = session.createQueue(subject);
consumer = session.createConsumer(destination);
}
#Override
public void onMessage(Message message) {
System.out.println("onMessage");
messagesReceived++;
if (message instanceof TextMessage) {
try {
TextMessage txtMsg = (TextMessage) message;
String msg = txtMsg.getText();
if(client.sendMessage(msg)) {
if(transacted) {
System.out.println("Call succeeded - committing message");
session.commit();
}
//message.acknowledge();
} else {
if(transacted) {
System.out.println("Webservice call failed. Rolling back message");
session.rollback();
}
}
} catch (JMSException e) {
e.printStackTrace();
}
}
}
Now, the message is being resent every 1000ms as specified in the Redelivery Policy.
Hope this helps someone else! :)
You don't have to use transactions, CLIENT_ACK/Session.recover() will work as well...
Messages are redelivered to a client when any of the following occurs:
A transacted session is used and rollback() is called.
A transacted session is closed before commit is called.
A session is using CLIENT_ACKNOWLEDGE and Session.recover() is called.
see http://activemq.apache.org/message-redelivery-and-dlq-handling.html
Related
I am trying to find a bug is some RabbitMQ client code that was developed six or seven years ago. The code was modified to allow for delayed messages. It seems that connections are created to the RabbitMQ server and then never destroyed. Each exists in a separate thread so I end up with 1000's of threads. I am sure the problem is very obvious / simple - but I am having trouble seeing it. I have been looking at the exchangeDeclare method (the commented out version is from the original code which seemed to work), but I have been unable to find the default values for autoDelete and durable which are being set in the modified code. The method below in within a Spring service class. Any help, advice, guidance and pointing out huge obvious errors appreciated!
private void send(String routingKey, String message) throws Exception {
String exchange = applicationConfiguration.getAMQPExchange();
Map<String, Object> args = new HashMap<String, Object>();
args.put("x-delayed-type", "fanout");
Map<String, Object> headers = new HashMap<String, Object>();
headers.put("x-delay", 10000); //delay in miliseconds i.e 10secs
AMQP.BasicProperties.Builder props = new AMQP.BasicProperties.Builder().headers(headers);
Connection connection = null;
Channel channel = null;
try {
connection = myConnection.getConnection();
}
catch(Exception e) {
log.error("AMQP send method Exception. Unable to get connection.");
e.printStackTrace();
return;
}
try {
if (connection != null) {
log.debug(" [CORE: AMQP] Sending message with key {} : {}",routingKey, message);
channel = connection.createChannel();
// channel.exchangeDeclare(exchange, exchangeType);
channel.exchangeDeclare(exchange, "x-delayed-message", true, false, args);
// channel.basicPublish(exchange, routingKey, null, message.getBytes());
channel.basicPublish(exchange, routingKey, props.build(), message.getBytes());
}
else {
log.error("Total AMQP melt down. This should never happen!");
}
}
catch(Exception e) {
log.error("AMQP send method Exception. Unable to get send.");
e.printStackTrace();
}
finally {
channel.close();
}
}
This is the connection class
#Service
public class PersistentConnection {
private static final Logger log = LoggerFactory.getLogger(PersistentConnection.class);
private static Connection myConnection = null;
private Boolean blocked = false;
#Autowired ApplicationConfiguration applicationConfiguration;
#PreDestroy
private void destroy() {
try {
myConnection.close();
} catch (IOException e) {
log.error("Unable to close AMQP Connection.");
e.printStackTrace();
}
}
public Connection getConnection( ) {
if (myConnection == null) {
start();
}
return myConnection;
}
private void start() {
log.debug("Building AMQP Connection");
ConnectionFactory factory = new ConnectionFactory();
String ipAddress = applicationConfiguration.getAMQPHost();
String user = applicationConfiguration.getAMQPUser();
String password = applicationConfiguration.getAMQPPassword();
String virtualHost = applicationConfiguration.getAMQPVirtualHost();
String port = applicationConfiguration.getAMQPPort();
try {
factory.setUsername(user);
factory.setPassword(password);
factory.setVirtualHost(virtualHost);
factory.setPort(Integer.parseInt(port));
factory.setHost(ipAddress);
myConnection = factory.newConnection();
}
catch (Exception e) {
log.error("Unable to initialise AMQP Connection.");
e.printStackTrace();
}
myConnection.addBlockedListener(new BlockedListener() {
public void handleBlocked(String reason) throws IOException {
// Connection is now blocked
log.warn("Message Server has blocked. It may be resource limitted.");
blocked = true;
}
public void handleUnblocked() throws IOException {
// Connection is now unblocked
log.warn("Message server is unblocked.");
blocked = false;
}
});
}
public Boolean isBlocked() {
return blocked;
}
}
I have an application that queues and deques messages from Oracle AQ using the JMS interface. When the application is running items get queued and dequeued and I can see queued items in the queue table. However, one the application shuts down the queue table is cleared and the application cannot access the previously queued items. Any idea what might cause that behavior?
The Oracle AQ is created using this code:
BEGIN
dbms_aqadm.create_queue_table(
queue_table => 'schema.my_queuetable',
sort_list =>'priority,enq_time',
comment => 'Queue table to hold my data',
multiple_consumers => FALSE, -- THis is necessary so that a message is only processed by a single consumer
queue_payload_type => 'SYS.AQ$_JMS_OBJECT_MESSAGE',
compatible => '10.0.0',
storage_clause => 'TABLESPACE LGQUEUE_IRM01');
END;
/
BEGIN
dbms_aqadm.create_queue (
queue_name => 'schema.my_queue',
queue_table => 'schema.my_queuetable');
END;
/
BEGIN
dbms_aqadm.start_queue(queue_name=>'schema.my_queue');
END;
/
I also have a Java class for connecting to the queue, queueing items and processing dequeued items like this:
public class MyOperationsQueueImpl implements MyOperationsQueue {
private static final Log LOGGER = LogFactory.getLog(MyOperationsQueueImpl.class);
private final QueueConnection queueConnection;
private final QueueSession producerQueueSession;
private final QueueSession consumerQueueSession;
private final String queueName;
private final QueueSender queueSender;
private final QueueReceiver queueReceiver;
private MyOperationsQueue.MyOperationEventReceiver eventReceiver;
public MyOperationsQueueImpl(DBUtils dbUtils, String queueName) throws MyException {
this.eventReceiver = null;
this.queueName = queueName;
try {
DataSource ds = dbUtils.getDataSource();
QueueConnectionFactory connectionFactory = AQjmsFactory.getQueueConnectionFactory(ds);
this.queueConnection = connectionFactory.createQueueConnection();
// We create separate producer and consumer sessions because that is what is recommended by the docs
// See: https://docs.oracle.com/javaee/6/api/javax/jms/Session.html
this.producerQueueSession = this.queueConnection.createQueueSession(false, Session.AUTO_ACKNOWLEDGE);
this.consumerQueueSession = this.queueConnection.createQueueSession(false, Session.AUTO_ACKNOWLEDGE);
this.queueSender = this.producerQueueSession.createSender(this.producerQueueSession.createQueue(this.queueName));
this.queueReceiver = this.consumerQueueSession.createReceiver(this.consumerQueueSession.createQueue(this.queueName));
this.queueConnection.start();
} catch (JMSException| NamingException exception) {
throw new MyOperationException("Failed to create MyOperationsQueue", exception);
}
}
#Override
protected void finalize() throws Throwable {
this.queueReceiver.close();
this.queueSender.close();
this.consumerQueueSession.close();
this.producerQueueSession.close();
this.queueConnection.close();
super.finalize();
}
#Override
public void submitMyOperation(MyOperationParameters myParameters) throws MyOperationException {
try {
ObjectMessage message = this.producerQueueSession.createObjectMessage(myParameters);
this.queueSender.send(message);
synchronized (this) {
if(this.eventReceiver != null) {
this.eventReceiver.onOperationSubmitted(message.getJMSMessageID(), myParameters);
}
}
} catch (JMSException exc) {
throw new MyOperationException("Failed to submit my operation", exc);
}
}
#Override
public void setMyOperationEventReceiver(MyOperationEventReceiver operationReceiver) throws MyOperationException {
LOGGER.debug("Setting my operation event receiver");
synchronized (this) {
if(this.eventReceiver != null) {
throw new IllegalStateException("Cannot set an operation event receiver if it is already set");
}
this.eventReceiver = operationReceiver;
try {
this.queueReceiver.setMessageListener(message -> {
LOGGER.debug("New message received from queue receiver");
try {
ObjectMessage objectMessage = (ObjectMessage) message;
eventReceiver.onOperationReady(message.getJMSMessageID(), (MyOperationParameters) objectMessage.getObject());
} catch (Exception exception) {
try {
eventReceiver.onOperationRetrievalFailed(message.getJMSMessageID(), exception);
} catch (JMSException innerException) {
LOGGER.error("Failed to get message ID for JMS Message: "+message, innerException);
}
}
});
} catch (JMSException exc) {
throw new MyOperationException("Failed to set My message listener", exc);
}
}
}
}
This code should read from the queue, if the queue is empty, then repeat reading through the timer check the format of Text or Byte. Is it correct in this format to check an empty queue? And will the timer work in this case?
It is not possible to check yet because the MQ queue is not configured.
public class Main {
public static void main(String[] args) {
boolean tru = true;
try {
/*MQ Конфигурация подключения*/
MQQueueConnectionFactory mqQueueConnectionFactory = new MQQueueConnectionFactory();
mqQueueConnectionFactory.setHostName("localhost");
mqQueueConnectionFactory.setChannel("SVRCONN");
mqQueueConnectionFactory.setPort(1414);
mqQueueConnectionFactory.setIntProperty(WMQConstants.WMQ_CONNECTION_MODE, WMQConstants.WMQ_CM_CLIENT);
mqQueueConnectionFactory.setQueueManager("MQ_APPLE");
mqQueueConnectionFactory.setTransportType(JMSC.MQJMS_TP_CLIENT_MQ_TCPIP);
QueueConnection queueConnection = mqQueueConnectionFactory.createQueueConnection("name", "pass");
MQQueueSession session = (MQQueueSession) queueConnection.createQueueSession(false, Session.AUTO_ACKNOWLEDGE);
MQQueue queue = (MQQueue) session.createQueue("queue:///Q1");
MQQueueReceiver receiver = (MQQueueReceiver) session.createReceiver(queue);
queueConnection.start();
while(tru){
TextMessage receivedMessage = (TextMessage) receiver.receive();
if(receivedMessage != null){
MStart(receivedMessage);
tru = false;
} else {
Timer timer = new Timer(10000,new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
System.out.println("Timer Run");
}
});
timer.start();
}
}
receiver.close();
session.close();
queueConnection.close();
} catch (JMSException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
}
public static void MStart(TextMessage receivedMessage) throws JMSException {
if (receivedMessage instanceof BytesMessage) {
TextMessage textMessage = (TextMessage) receivedMessage;
System.out.println("Received message '"
+ textMessage.getText() + "'");
} else if (receivedMessage instanceof TextMessage) {
System.out.println("Received message: " + receivedMessage.getText());
}
}
}
Note that your receiver.receive(); call will block indefinitely. From MQMessageConsumer doc :
Receives the next message produced for this message consumer. This
call blocks indefinitely until a message is produced or until this
message consumer is closed.
if you want to read from the queue for a specified amount of time, maybe you should better use the receive(long timeout) method :
public javax.jms.Message receive(long timeout)
throws javax.jms.JMSException
Receives the next message that arrives within the specified timeout
interval. This call blocks until a message arrives, the timeout
expires, or this message consumer is closed. A timeout of zero never
expires, and the call blocks indefinitely.
Unless there is a need to use timer, I prefer using a receive(timeout). If there was a message in the queue, the receive call will return with message else it will timeout with exception with 2033 reason code will be thrown. You can catch this exception and call receive again to wait for message. This will also allow you stop this thread when asked to.
Instead of (TextMessage) receiver.receive() just do Message msg = receiver.receive() and then use if(msg instanceof TextMessage) to determine type of message received.
I've created an app that must consumes an activemq topic, but in this project we don't need to use spring xml. I only created one class called ActiveMQConsumer that implements MessageListener and overrides onMessage method, but nothing happens... Is this approach ok? or something missing? I'm currently connecting through tcp.
public class ActiveMQConsumer implements MessageListener {
public ActiveMQConsumer() throws JMSException {
try {
ConnectionFactory factory = new ActiveMQConnectionFactory(CATALOG_BROKER_URL.getValue());
Connection connection = factory.createConnection();
connection.start();
Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
Destination destination = session.createTopic(CATALOG_TOPIC_NAME.getValue());
MessageConsumer consumer = session.createConsumer(destination);
consumer.setMessageListener(this);
} catch (JMSException e) {
System.out.println("Error");
}
}
#Override
public void onMessage(final Message message) {
LOGGER.info("Start consuming message from Catalog");
try {
if (message instanceof TextMessage) {
TextMessage txtMessage = (TextMessage) message;
System.out.println("Message: " + txtMessage.getText());
} else {
System.out.println("Invalid Message !");
}
} catch (JMSException e) {
System.out.println("Exception" + e);
}
}
}
I've solved my problem using an ContextListener to call an runnable class. Just put it into web.xml and done.
I have a Glassfish 3.1.2 server running on a remote machine (JDK 1.6.0_30). The following code is the stand-alone client running in a Java SE environment, connecting to the JMS using a JNDI lookup. The client is publisher and subscriber at the same time.
I created the JMS connection pool and topic as follows:
./asadmin create-jms-resource --restype javax.jms.ConnectionFactory jms/TopicConnectionFactory
./asadmin create-jms-resource --restype javax.jms.Topic jms/TopicUpdate
I start two instances of this client. The messages seem to be delivered - no errors - but the messages do not arrive at the subscribers ...
What I am doing wrong ?
Any help appreciated - many thanks in advance!
public class JMS implements MessageListener {
private TopicConnectionFactory factory;
private TopicConnection connection;
private Topic topic;
private void subscribe() {
try {
System.setProperty("org.omg.CORBA.ORBInitialHost", "192.168.1.6");
System.setProperty("org.omg.CORBA.ORBInitialPort", "3700");
InitialContext ctx = new InitialContext();
factory = (TopicConnectionFactory)ctx.lookup("jms/TopicConnectionFactory");
topic = (Topic)ctx.lookup("jms/TopicUpdate");
connection = factory.createTopicConnection();
TopicSession session = connection.createTopicSession(false, Session.AUTO_ACKNOWLEDGE);
TopicSubscriber subscriber = session.createSubscriber(topic);
subscriber.setMessageListener(this);
connection.start();
while(true) {
Thread.sleep(5000);
sendMessage();
}
} catch (InterruptedException ex) {
Logger.getLogger(JMS.class.getName()).log(Level.SEVERE, null, ex);
} catch (NamingException ex) {
Logger.getLogger(JMS.class.getName()).log(Level.SEVERE, null, ex);
} catch (JMSException ex) {
Logger.getLogger(JMS.class.getName()).log(Level.SEVERE, null, ex);
}
}
private void sendMessage() {
try {
TopicSession session = connection.createTopicSession(true, Session.AUTO_ACKNOWLEDGE);
TopicPublisher publisher = session.createPublisher(topic);
TextMessage message = session.createTextMessage();
message.setText("Message from client.");
publisher.send(message);
session.close();
System.out.println("Message sent.");
} catch (JMSException ex) {
Logger.getLogger(JMS.class.getName()).log(Level.SEVERE, null, ex);
}
}
#Override
public void onMessage(Message msg) {
System.out.println("Message received.");
}
public JMS() {
subscribe();
}
public static void main(String[] args) {
new JMS();
}
}
When you use true as the first argument when creating a session, the acknowledge mode is ignored and you're assumed to be transacted. try it with the first argument as false.
Just so it's clear, modify this line of code:
TopicSession session = connection.createTopicSession(true, Session.AUTO_ACKNOWLEDGE);
to be :
TopicSession session = connection.createTopicSession(false, Session.AUTO_ACKNOWLEDGE);
In your send message method.
It's good idea to have publisher and subscriber different.I
Here is code how to subscribe using Spring JMS template.
public class MsgReader implements
SessionAwareMessageListener<Message> {
#Override
public void onMessage(Message message, Session session) throws JMSException {
if (message instanceof TextMessage) {
try {
System.out.println(((TextMessage) message).getText());
} catch (JMSException ex) {
throw new RuntimeException(ex);
}
} else {
throw new IllegalArgumentException(
"Message must be of type TextMessage");
}
}
}
Spring Bean file.
Finally load beans.
public class SpringJMSTest {
/**
* #param args
*/
public static void main(String[] args) {
ApplicationContext context = new FileSystemXmlApplicationContext(new String[]{"/resource/consumerBean.xml"});
}
}
Now you will start receiving messages in console.