private List<JsonNode> pullMessages(int interval) {
List<JsonNode> msgs = new ArrayList<JsonNode>();
if (!isBlank(QUEUE_URL)) {
try {
ReceiveMessageRequest receiveReq = new ReceiveMessageRequest(QUEUE_URL);
receiveReq.setMaxNumberOfMessages(MAX_MESSAGES);
receiveReq.setWaitTimeSeconds(interval);
List<Message> list = sqs.receiveMessage(receiveReq).getMessages();
if (list != null && !list.isEmpty()) {
if (DEBUG) logger.info("Received {} messages from queue.", list.size());
List<DeleteMessageBatchRequestEntry> deletionList =
new ArrayList<DeleteMessageBatchRequestEntry>();
for (Message message : list) {
if (!isBlank(message.getBody())) {
msgs.add(mapper.readTree(message.getBody()));
}
deletionList.add(
new DeleteMessageBatchRequestEntry(
UUID.randomUUID().toString(), message.getReceiptHandle()));
}
sqs.deleteMessageBatch(QUEUE_URL, deletionList);
}
} catch (IOException ex) {
logger.error(ex.getMessage());
} catch (AmazonServiceException ase) {
logException(ase);
} catch (AmazonClientException ace) {
logger.error("Could not reach SQS. {}", ace.getMessage());
}
}
return msgs;
}
public static void deleteTaskMessage(Message msg, String sqsUrl, AmazonSQS sqs) {
String handle = msg.getReceiptHandle();
try {
sqs.deleteMessage(new DeleteMessageRequest(sqsUrl, handle));
logger.info("Message deleted: " + msg.getBody());
} catch (AmazonServiceException e) {
logger.severe(e.getMessage());
} catch (AmazonClientException e) {
logger.severe(e.getMessage());
}
}
@Override
public boolean equals(Object obj) {
if (this == obj) return true;
if (obj == null) return false;
if (obj instanceof Message == false) return false;
Message other = (Message) obj;
if (other.getMessageId() == null ^ this.getMessageId() == null) return false;
if (other.getMessageId() != null && other.getMessageId().equals(this.getMessageId()) == false)
return false;
if (other.getReceiptHandle() == null ^ this.getReceiptHandle() == null) return false;
if (other.getReceiptHandle() != null
&& other.getReceiptHandle().equals(this.getReceiptHandle()) == false) return false;
if (other.getMD5OfBody() == null ^ this.getMD5OfBody() == null) return false;
if (other.getMD5OfBody() != null && other.getMD5OfBody().equals(this.getMD5OfBody()) == false)
return false;
if (other.getBody() == null ^ this.getBody() == null) return false;
if (other.getBody() != null && other.getBody().equals(this.getBody()) == false) return false;
if (other.getAttributes() == null ^ this.getAttributes() == null) return false;
if (other.getAttributes() != null
&& other.getAttributes().equals(this.getAttributes()) == false) return false;
return true;
}
@Override
public void run() {
while (true) {
// take element from request queue
List<Message> messages = this.sqsImplementation.retrrieveElementFromQueue(this.taskQueue);
if (null != messages && messages.size() > 0) {
for (Message message : messages) {
String[] messageParts = message.getBody().split(" ");
// check for entry in a dynamoDB table
boolean isEntryExist = this.dbImpl.checkIfEntryExist(this.tableName, messageParts[0]);
if (!isEntryExist) {
// insert task in a dynamoDB table
this.dbImpl.insertElementInTable(tableName, messageParts[0]);
try {
Thread.sleep(Integer.parseInt(messageParts[1]));
} catch (NumberFormatException e) {
e.printStackTrace();
} catch (InterruptedException e) {
e.printStackTrace();
}
// insert element in response queue
this.sqsImplementation.insertElementInQueue(responseQueue, messageParts[0] + " 0");
// Delete a message from a request queue
String messageReceiptHandle = message.getReceiptHandle();
this.sqsImplementation
.getSqs()
.deleteMessage(
new DeleteMessageRequest(
sqsImplementation.getQueueURL(this.taskQueue), messageReceiptHandle));
} else {
System.out.println("Duplicate Entry Found" + messageParts[0]);
}
}
}
}
}
public static void main(String[] args) {
// Get Credentials
AWSCredentials credentials = Credentials.getCredentials();
// Get SQS client
AmazonSQS sqs = new AmazonSQSClient(credentials);
// Start processing the messages from inbox queue
for (; ; ) {
// Receive messages
System.out.println("Receiving messages from Inbox Queue.\n");
ReceiveMessageRequest receiveMessageRequest = new ReceiveMessageRequest(inboxQueueUrl);
List<Message> messages = sqs.receiveMessage(receiveMessageRequest).getMessages();
if (messages.isEmpty()) {
continue;
} else {
for (Message message : messages) {
// temp variable to handle the integers in the message
// MessageAttributeValue a=null;
// MessageAttributeValue b=null;
String a = "";
String b = "";
System.out.println(" Message");
System.out.println(" MessageId: " + message.getMessageId());
System.out.println(" ReceiptHandle: " + message.getReceiptHandle());
System.out.println(" MD5OfBody: " + message.getMD5OfBody());
System.out.println(" Body: " + message.getBody());
String receiptHandle = message.getReceiptHandle();
String[] numbers = message.getBody().split(":");
/*Map<String, MessageAttributeValue> e = message.getMessageAttributes();
//for (Entry<String, MessageAttributeValue> entry: e.entrySet()) {
for(Entry<String, String> entry : message.getAttributes().entrySet()){
System.out.println(" Attribute");
String temp1="firstNumber";
String temp2="secondNumber";
if(temp1.compareTo(entry.getKey())==0){
a=entry.getValue().toString();
}
if(temp2.compareTo(entry.getKey())==0){
b=entry.getValue().toString();
}
System.out.println(" Name: " + entry.getKey());
System.out.println(" Value: " + entry.getValue());
}
*/
// process the numbers
String sum = numbers[0] + "+" + numbers[1];
String diff = numbers[0] + "-" + numbers[1];
System.out.println(sum);
System.out.println(diff);
Map<String, MessageAttributeValue> messageAttributes = new HashMap<>();
messageAttributes.put(
"sum", new MessageAttributeValue().withDataType("String").withStringValue(sum));
messageAttributes.put(
"diff", new MessageAttributeValue().withDataType("String").withStringValue(diff));
SendMessageRequest request = new SendMessageRequest();
request.withMessageBody("A test message body.");
request.withQueueUrl(outboxQueueUrl);
request.withMessageAttributes(messageAttributes);
sqs.sendMessage(request);
// delete the message from inbox queue
sqs.deleteMessage(new DeleteMessageRequest(inboxQueueUrl, receiptHandle));
}
}
System.out.println();
}
}