Develop Reference

How to move error message to Azure dead letter queue(Topics - Subscription) using Java?

I need to send my messages to Dead letter queue from azure topic subscription incase of any error while reading and processing the message from topic. So I tried testing pushing message directly to DLQ.
My sample code will be like
static void sendMessage()
{
// create a Service Bus Sender client for the queue
ServiceBusSenderClient senderClient = new ServiceBusClientBuilder()
.connectionString(connectionString)
.sender()
.topicName(topicName)
.buildClient();
// send one message to the topic
senderClient.sendMessage(new ServiceBusMessage("Hello, World!"));
}
static void resceiveAsync() {
ServiceBusReceiverAsyncClient receiver = new ServiceBusClientBuilder()
.connectionString(connectionString)
.receiver()
.topicName(topicName)
.subscriptionName(subName)
.buildAsyncClient();
// receive() operation continuously fetches messages until the subscription is disposed.
// The stream is infinite, and completes when the subscription or receiver is closed.
Disposable subscription = receiver.receiveMessages().subscribe(message -> {
System.out.printf("Id: %s%n", message.getMessageId());
System.out.printf("Contents: %s%n", message.getBody().toString());
}, error -> {
System.err.println("Error occurred while receiving messages: " + error);
}, () -> {
System.out.println("Finished receiving messages.");
});
// Continue application processing. When you are finished receiving messages, dispose of the subscription.
subscription.dispose();
// When you are done using the receiver, dispose of it.
receiver.close();
}
I tried getting the deadletter queue path
String dlq = EntityNameHelper.formatDeadLetterPath(topicName);
I got path of dead letter queue like = "mytopic/$deadletterqueue"
But It's not working while passing path as topic name. It throwing a Entity topic not found exception.
Any one can you please advise me on this
Reference :
How to move error message to Azure dead letter queue using Java?
https://learn.microsoft.com/en-us/azure/service-bus-messaging/service-bus-dead-letter-queues#moving-messages-to-the-dlq
How to push the failure messages to Azure service bus Dead Letter Queue in Spring Boot Java?
https://learn.microsoft.com/en-us/azure/service-bus-messaging/service-bus-java-how-to-use-topics-subscriptions-legacy#receive-messages-from-a-subscription

You probably know that a message will be automatically moved to the deadletter queue if you throw exceptions during processing, and the maximum delievery count is exceeded. If you want to explicitly move the message to the DLQ, you can do so as well. A common case for this is if you know that the message can never succeed because of its contents.
You cannot send new messages directly to the DLQ, because then you would have two messages in the system. You need to call a special operation on the parent entity. Also, <topic path>/$deadletterqueue does not work, because this would be the DLQ of all subscriptions. The correct entity path is built like this:
<queue path>/$deadletterqueue
<topic path>/Subscriptions/<subscription path>/$deadletterqueue
https://github.com/Azure/azure-service-bus/blob/master/samples/Java/azure-servicebus/DeadletterQueue/src/main/java/com/microsoft/azure/servicebus/samples/deadletterqueue/DeadletterQueue.java
This sample code is for queues, but you should be able to adapt it to topics quite easily:
// register the RegisterMessageHandler callback
receiver.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")) {
// ...
} else {
return receiver.deadLetterAsync(message.getLockToken());
}
return receiver.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);

Can my selenium framework consume an incoming message

I would like to know how my Selenium framework can dequeue a message sitting in a message queue. I have built an application to send a JSON string containing k/v pairs to a message queue.
My architecture is as follows and separate apps:
A JSP Web Application exists accepting parameters resulting in a JSON string
A message sender exists and takes the JSON string and publishes it to a Queue
A message consumer exists and consumes the Messages. Its basically just sitting here
A Selenium Java Framework exists, but I would like to process the messages and for each message it will interpret the k/v pairs and kicks off the script.
I would like to use the messages already in the queue and process these messages within the selenium framework, how can I achieve this?
I will appreciate the help. I have edited the question with the code
This is the code snippet to send the JSON Message
public class MessageSender {
public static void main(String[] args) throws IOException {
SingleNumberLogin generateLogin = new SingleNumberLogin();
//function call to build the JSON object
String jsonQueue = generateLogin.buildJASONObject();
ConnectionFactory conFactory = new ConnectionFactory();
try {
Connection connInterface = conFactory.newConnection();
Channel mqChannel = connInterface.createChannel();
mqChannel.queueDeclare("MyQueue",false,false,false,null);
//Just assigning json to another string, then publish the message
String myMessage = jsonQueue;
mqChannel.basicPublish("","MyQueue",false ,false, null,myMessage.getBytes());
}catch (
IOException | TimeoutException e)
{
System.out.println(e.getStackTrace());
}
conFactory.setUsername("guest");
conFactory.setPassword("guest");
conFactory.setVirtualHost("/");
conFactory.setHost("localhost");
conFactory.setPort(5672);
}
}
code snippet for consumer code that I have inserted into the startup function of the automation script, so if a message arrives a single test case is executed
#BeforeTest
public static void initializeTestBaseSetup() throws Exception, IOException, TimeoutException {
ConnectionFactory conFactory = new ConnectionFactory();
Connection connInterface = conFactory.newConnection();
Channel mqChannel = connInterface.createChannel();
mqChannel.queueDeclare("MyQueue",false,false,false,null);
mqChannel.basicConsume("MyQueue", true, (consumerTag, message) -> {
//convert to byte array
String m = new String (message.getBody(), "UTF-8");
System.out.println("Message received" + m);
}, consumerTag -> {
});
}
Output JSON
JSON Message received 2020-08-28T20:39:30.845{
"NUMBER": "0000011111",
"Type": "BAU",
"User": "MyUser ",
"Email": "riidonesh#gmail.com",
}
When tested in isolation, it works perfectly fine, what I mean is that I send the message and check that the consumer receives it, adding the consumer code to my framework is where i am stuck.

I would suggest you don't think about what you have as a "selenium framework" - think of it as a "java framework".
Selenium is a set of libraries that allow you automate the web browser at a GUI level. The framework is the coded solution to facilitate creation and management of your test suite - it doesn't have to be limited to selenium and chances that's already just one of its components.
Trying to answer your question directly:
SELENIUM cannot read messages
JAVA can read messages
If your rabbitmq has a web front end then you may be able to use selenium for it, but this isn't a very efficient or a logical solution.
What you might want to consider, and what i would do, is extending your framework to use the rabbitmq libraries to process messages as you need. These libraries are designed for this task.
You say:
I would like to process the messages and for each message it will
interpret the k/v pairs and kicks off the script.
I understand this to mean that the messages are the pre-req data for the tests. If you want to read the values of a message before the test you can either:
Place the get/read in a generic #Before method
or if it's a specific message per test case, add it into the start of the test.
You're working in java so you can do whatever you want really.
To get you started, the rabbitmq tutorial starts here.
This is there hello world example for reading messages from the queue:
public class Recv {
private final static String QUEUE_NAME = "hello";
public static void main(String[] argv) throws Exception {
ConnectionFactory factory = new ConnectionFactory();
factory.setHost("localhost");
Connection connection = factory.newConnection();
Channel channel = connection.createChannel();
channel.queueDeclare(QUEUE_NAME, false, false, false, null);
System.out.println(" [*] Waiting for messages. To exit press CTRL+C");
}
}

Glassfish JMS Queue Not Found In JNDI Context

I need help.
The Glassfish Admin Console screen below shot below shows that I've set up three JMS Destination Resources. All are identical except for the names. But my JNDI lookup from a local java client (Glassfish is also local) can only see the first two. Client code and console out put is below screen shot.
I don't even know where to look to begin figuring out why one and two work, and three doesn't. Can anyone suggest anything. This should be as basic as it get's. All three are identically set up. None have any additional properties set. I really need help or direction.
CODE:
public class SrackOverflow1 {
public static void main(String[] args) {
Properties env = new Properties();
env.put ("java.naming.factory.initial", "com.sun.jndi.fscontext.RefFSContextFactory");
env.put ("java.naming.provider.url","file:///C:/glassfish4/mq/opt/java/my_broker");
try {
Context jndiContext = (Context) new InitialContext(env);
Queue queueOne = (Queue) jndiContext.lookup("jms/goSendQueue");
System.out.println("queueOne ok:\n" + queueOne);
Queue queueTwo = (Queue) jndiContext.lookup("jms/goReceiveQueue");
System.out.println("\nqueueTwo ok:\n" + queueTwo);
Queue queueThree = (Queue) jndiContext.lookup("jms/goTestQueue");
System.out.println("\nqueueThree ok:\n" + queueThree);
} catch (NamingException e) {
System.out.println("\nThrew Naming Exception\nerror msg: " + e.getMessage() +"\n");
e.printStackTrace();
}
}
CONSOLE:
queueOne ok:
Sun Java System MQ Destination
getName(): goSendQueuq
Class: com.sun.messaging.Queue
getVERSION(): 3.0
isReadonly(): false
getProperties(): {imqDestinationName=goSendQueuq, imqDestinationDescription=A Description for the Destination
Object}
queueTwo ok:
Sun Java System MQ Destination
getName(): goReceiveQueue
Class: com.sun.messaging.Queue
getVERSION(): 3.0
isReadonly(): false
getProperties(): {imqDestinationName=goReceiveQueue, imqDestinationDescription=A Description for the Destinati
on Object}
Threw Naming Exception
error msg: jms/goTestQueue
javax.naming.NameNotFoundException: jms/goTestQueue
at com.sun.jndi.fscontext.RefFSContext.getObjectFromBindings(RefFSContext.java:400)
at com.sun.jndi.fscontext.RefFSContext.lookupObject(RefFSContext.java:327)
at com.sun.jndi.fscontext.RefFSContext.lookup(RefFSContext.java:146)
at com.sun.jndi.fscontext.FSContext.lookup(FSContext.java:127)
at javax.naming.InitialContext.lookup(Unknown Source)
at org.america3.testclasses.SrackOverflow1.main(SrackOverflow1.java:21)

make mail mark as unread after polling - Apache Camel

Am using apache camel, With Polling consumer, when poll my mail is mark as read.
options : delete=false&peek=false&unseen=true
After polling , when i am processing the attachment, if any error occurs , i want to make the mail as "unread". So that i can pool again later.
public void process(Exchange exchange) throws Exception {
Map<String, DataHandler> attachments = exchange.getIn().getAttachments();
Message messageCopy = exchange.getIn().copy();
if (messageCopy.getAttachments().size() > 0) {
for (Map.Entry<String, DataHandler> entry : messageCopy.getAttachments().entrySet()) {
DataHandler dHandler = entry.getValue();
// get the file name
String filename = dHandler.getName();
// get the content and convert it to byte[]
byte[] data =
exchange.getContext().getTypeConverter().convertTo(byte[].class, dHandler.getInputStream());
log.info("Downloading attachment, file name : " + filename);
InputStream fileInputStream = new ByteArrayInputStream(data);
try {
// Processing attachments
// if any error occurs here, i want to make the mail mark as unread
} catch (Exception e) {
log.info(e.getMessage());
}
}
}
}
I noticed the option peek, by setting it to true, It will not make the mail mark as read during polling, in that case is there any option to make it mark as read after processing.

To get the result that you want you should have options
peek=true&unseen=true
The peek=true option is supposed to ensure that messages remain the exact state on the mail server as they where before polling even if there is an exception. However, currently it won't work. This is actually a bug in Camel Mail component. I've submitted a patch to https://issues.apache.org/jira/browse/CAMEL-9106 and this will probably be fixed in a future release.
As a workaround you can set mapMailMessages=false but then you will have to work with the email message content yourself. In Camel 2.15 onward you also have postProcessAction option and with that you could probably remove the SEEN flags from messages with processing errors. Still, I would recommend waiting for the fix though.

We can set the mail unread flag with the following code
public void process(Exchange exchange) throws Exception {
final Message mailMessage = exchange.getIn(MailMessage.class).getMessage();
mailMessage.setFlag(Flag.SEEN, false);
}

java websphere MQ

My aim is to put n number of messages in a for loop to a WebSphere MQ queue using WebSphere MQ java programming.
My java program will run as a standalone program.
If any exception in between , I need to rollback all the messages.
If no exception then I should commit all the messages .
The outside world should not see my messages in the queue until I complete fully.
How do I achieve this?
Updated with sample code as per reply from T.Rob:
Please check if sample code is fine ?
Does setting MQGMO_SYNCPOINT is only related to my program's invocation ?
(because similar programs running parallely will also be putting messages on the same queue and those messages should not gett affected by my program's SYNCPOINT.)
public void sendMsg() {
MQQueue queue = null;
MQQueueManager queueManager = null;
MQMessage mqMessage = null;
MQPutMessageOptions pmo = null;
System.out.println("Entering..");
try {
MQEnvironment.hostname = "x.x.x.x";
MQEnvironment.channel = "xxx.SVRCONN";
MQEnvironment.port = 9999;
queueManager = new MQQueueManager("XXXQMANAGER");
int openOptions = MQConstants.MQOO_OUTPUT;
queue = queueManager.accessQueue("XXX_QUEUENAME", openOptions, null, null, null);
pmo = new MQPutMessageOptions();
pmo.options = CMQC.MQGMO_SYNCPOINT;
String input = "testing";
System.out.println("sending messages....");
for (int i = 0; i < 10; i++) {
input = input + ": " + i;
mqMessage = new MQMessage();
mqMessage.writeString(input);
System.out.println("Putting message: " + i);
queue.put(mqMessage, pmo);
}
queueManager.commit();
System.out.println("Exiting..");
} catch (Exception e) {
e.printStackTrace();
try {
System.out.println("rolling back messages");
if (queueManager != null)
queueManager.backout();
} catch (MQException e1) {
e1.printStackTrace();
}
} finally {
try {
if (queue != null)
queue.close();
if (queueManager != null)
queueManager.close();
} catch (MQException e) {
e.printStackTrace();
}
}
}

WMQ supports both local and global (XA) units of work. The local units of work are available simply by specifying the option. Global XA transactions require a transaction manager, as mentioned by keithkreissl in another answer.
For what you described, a POJO doing messaging under syncpoint, specify MQC.MQGMO_SYNCPOINT in your MQGetMessageOptions. When you are ready to commit, issue the MQQManager.commit() or MQQManager.backout() call.
Note that the response and doc provided by ggrandes refers to the JMS and not Java classes. The Java classes use Java equivalents of the WMQ procedural API, can support many threads (doc) and even provide connection pooling (doc). Please refer to the Java documentation rather than the JMS documentation for the correct behavior. Also, I've linked to the WMQ V7.5 documentation which goes with the latest WMQ Java V7.5 client. The later clients have a lot more local functionality (tracing, flexible install path, MQClient.ini, etc.) and work with back-level QMgrs. It is highly recommended to be using the latest client and the download is free.

you only need to create a session with transaction enabled.
Session session;
// ...
boolean transacted = true;
session = connection.createSession(transacted, Session.AUTO_ACKNOWLEDGE);
try {
// ...do things...
session.commit();
} catch (Exception e) {
session.rollback();
}
// ...
WARN-NOTE: Sessions are not thread-safe ;-)
Doc Websphere MQ/JMS

If you have access to a transaction manager and more importantly an XATransaction wired up to your MQ access, you can start a transaction at the beginning of your message processing put all the messages on the queue then commit the transaction. Using the XATransactions it will not put any messages until the transaction commits. If you don't have access to that, you can do a little more plumbing by placing your messages in a local data object, wrap your code in a try/catch if no exceptions iterate through the local data object sending the messages. The issue with the later approach is that it will commit all your other processing but if a problem occurs in the sending of messages your other processing will not be rolled back.