Get by JMSMessageID, basic behaviour - #46

Author: matrober-uk

getbycorrelid_test.go

@@ -125,11 +125,10 @@ func TestSelectorParsing(t *testing.T) {
 	assert.Nil(t, correlIDErr)
 	assert.NotNil(t, correlIDConsumer)
 
-	// Check that we get an appropriate error when trying to create a consumer with
-	// a selector that is not (yet) supported.
+	// JMSMessageID selectors are now supported.
 	msgIDConsumer, msgIDErr := context.CreateConsumerWithSelector(queue, "JMSMessageID = 'ID:1234'")
-	assert.NotNil(t, msgIDErr)
-	assert.Nil(t, msgIDConsumer)
+	assert.Nil(t, msgIDErr)
+	assert.NotNil(t, msgIDConsumer)
 
 	// Check that we get an appropriate error when trying to create a consumer with
 	// a malformed selector.

getbymsgid_test.go

@@ -0,0 +1,91 @@
+/*
+ * Copyright (c) IBM Corporation 2022
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0, which is available at
+ * http://www.eclipse.org/legal/epl-2.0.
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ */
+package main
+
+import (
+	"fmt"
+	"reflect"
+	"testing"
+
+	"github.com/ibm-messaging/mq-golang-jms20/jms20subset"
+	"github.com/ibm-messaging/mq-golang-jms20/mqjms"
+	"github.com/stretchr/testify/assert"
+)
+
+/*
+ * Test receiving a specific message from a queue using its JMSMessageID
+ */
+func TestGetByMsgID(t *testing.T) {
+
+	// Loads CF parameters from connection_info.json and applicationApiKey.json in the Downloads directory
+	cf, cfErr := mqjms.CreateConnectionFactoryFromDefaultJSONFiles()
+	assert.Nil(t, cfErr)
+
+	// Creates a connection to the queue manager, using defer to close it automatically
+	// at the end of the function (if it was created successfully)
+	context, ctxErr := cf.CreateContext()
+	assert.Nil(t, ctxErr)
+	if context != nil {
+		defer context.Close()
+	}
+
+	// First, check the queue is empty
+	queue := context.CreateQueue("DEV.QUEUE.1")
+	consumer, conErr := context.CreateConsumer(queue)
+	assert.Nil(t, conErr)
+	if consumer != nil {
+		defer consumer.Close()
+	}
+	reqMsgTest, err := consumer.ReceiveNoWait()
+	assert.Nil(t, err)
+	assert.Nil(t, reqMsgTest)
+
+	// Put a couple of messages before the one we're aiming to get back
+	producer := context.CreateProducer().SetTimeToLive(10000)
+	producer.SendString(queue, "One")
+	producer.SendString(queue, "Two")
+
+	myMsgThreeStr := "Three"
+	sentMsg := context.CreateTextMessageWithString(myMsgThreeStr)
+	err = producer.Send(queue, sentMsg)
+	assert.Nil(t, err)
+	sentMsgID := sentMsg.GetJMSMessageID()
+
+	// Put a couple of messages after the one we're aiming to get back
+	producer.SendString(queue, "Four")
+	producer.SendString(queue, "Five")
+
+	// Create the consumer to read by CorrelID
+	correlIDConsumer, correlErr := context.CreateConsumerWithSelector(queue, "JMSMessageID = '"+sentMsgID+"'")
+	assert.Nil(t, correlErr)
+	gotCorrelMsg, correlGetErr := correlIDConsumer.ReceiveNoWait()
+
+	// Clean up the remaining messages from the queue before we start checking if
+	// we got the right one back.
+	var cleanupMsg jms20subset.Message
+	for ok := true; ok; ok = (cleanupMsg != nil) {
+		cleanupMsg, err = consumer.ReceiveNoWait()
+	}
+
+	// Now do the comparisons
+	assert.Nil(t, correlGetErr)
+	assert.NotNil(t, gotCorrelMsg)
+	gotMsgID := gotCorrelMsg.GetJMSMessageID()
+	assert.Equal(t, sentMsgID, gotMsgID)
+
+	switch msg := gotCorrelMsg.(type) {
+	case jms20subset.TextMessage:
+		assert.Equal(t, myMsgThreeStr, *msg.GetText())
+	default:
+		fmt.Println(reflect.TypeOf(gotCorrelMsg))
+		assert.Fail(t, "Got something other than a text message")
+	}
+
+}

mqjms/ConsumerImpl.go

@@ -292,17 +292,23 @@ func applySelector(selector string, getmqmd *ibmmq.MQMD, gmo *ibmmq.MQGMO) error
 		return nil
 	}
 
-	// looking for something like "JMSCorrelationID = '01020304050607'"
+	// looking for something like
+	//   "JMSCorrelationID = '01020304050607'"
+	//   "JMSMessageID = '414d5120514d31202020202020202020bec0ba61034dbe40'"
 	clauseSplits := strings.Split(selector, "=")
 
 	if len(clauseSplits) != 2 {
 		return errors.New("Unable to parse selector " + selector)
 	}
 
-	if strings.TrimSpace(clauseSplits[0]) != "JMSCorrelationID" {
-		// Currently we only support correlID selectors, so error out quickly
+	selectorFieldName := strings.TrimSpace(clauseSplits[0])
+
+	if selectorFieldName != "JMSCorrelationID" &&
+		selectorFieldName != "JMSMessageID" {
+
+		// Currently we only support correlID and messageID selectors, so error out quickly
 		// if we see anything else.
-		return errors.New("Only selectors on JMSCorrelationID are currently supported")
+		return errors.New("Only selectors on JMSCorrelationID and JMSMessageID are currently supported")
 	}
 
 	// Trim the value.
@@ -314,13 +320,22 @@ func applySelector(selector string, getmqmd *ibmmq.MQMD, gmo *ibmmq.MQGMO) error
 
 		// Parse out the value, and convert it to bytes
 		stringSplits := strings.Split(value, "'")
-		correlIDStr := stringSplits[1]
+		selectorValue := stringSplits[1]
+
+		if selectorValue != "" {
+
+			selectorValueBytes := convertStringToMQBytes(selectorValue)
+
+			switch selectorFieldName {
+			case "JMSCorrelationID":
+				getmqmd.CorrelId = selectorValueBytes
+
+			case "JMSMessageID":
+				getmqmd.MsgId = selectorValueBytes
+			}
 
-		if correlIDStr != "" {
-			correlBytes := convertStringToMQBytes(correlIDStr)
-			getmqmd.CorrelId = correlBytes
 		} else {
-			return errors.New("No value was found for CorrelationID")
+			return errors.New("No value was found for selector string")
 		}
 
 	} else {