Exercise - Receive messages from Azure Service Bus - Training

5 minutes

Now, let's create a Spring Boot application that can receive messages from an Azure Service Bus queue.

Create a Spring Boot project

Let's open up a new terminal window, and just like we did with the sender Spring Boot application, we use the Spring Initializr to create a Spring Boot project.

curl https://start.spring.io/starter.tgz -d type=maven-project -d dependencies=web -d baseDir=spring-receiver-application -d bootVersion=2.4.1.RELEASE -d javaVersion=1.8 | tar -xzvf -

Receive messages from a Service Bus queue

Here again, we add the dependency and configuration.

Add the maven dependency for Service Bus Spring Boot Starter

In the pom.xml file in your spring-receiver-application, add the following command under dependencies:

            <dependency>
                <groupId>com.microsoft.azure</groupId>
                <artifactId>azure-servicebus-jms-spring-boot-starter</artifactId>
                <version>2.3.3</version>
            </dependency>

Add the configuration parameters

In the spring-receiver-application\src\main\resources folder, edit the application.properties file, add the following parameters:
```
server.port=9090

spring.jms.servicebus.connection-string=<xxxxx>
spring.jms.servicebus.idle-timeout=20000
```
Set the spring.jms.servicebus.connection-string property to the connection string to your Service Bus namespace, which you saved earlier.

Add code to receive messages from Service Bus

Next, we add business logic to receive messages from a Service Bus queue.

In the src/main/java/com/example/demo directory, create a ReceiveController.java file that has the following content:

package com.example.demo;

import org.springframework.jms.annotation.JmsListener;
import org.springframework.stereotype.Component;

@Component
public class ReceiveController {
    
    @JmsListener(destination = "test-queue-jms")
    public void receiveMessage(String message) {
        System.out.println("Received <" + message + ">");
    }
}

Run the application locally

Switch back to the root of the sample spring-receiver-application folder where the pom.xml file is located, and run the following command to start your Spring Boot application. This step assumes that you have mvn installed on your Windows computer, and it's in the PATH.
```
mvn spring-boot:run
```
After the application startup completes, you'll see the following log statements in the console window.
```
Received <Hello>
Received <HelloAgain>
Received <HelloOnceAgain>
```
The appearance of the statements indicates that the Spring Boot application is successfully receiving messages from the Service Bus queue.

See the entire workflow in action

If your sender application (from unit 4) is still running, you can select the following link to send a message to the Service Bus queue:

http://localhost:8080/messages?message=HelloOnceAgainAndAgain

Your receiver application receives the message from the Service Bus queue and displays it in your console.

Received <HelloOnceAgainAndAgain>

Continue

Exercise - Receive messages from Azure Service Bus