07 - Extending with Triggers (Consumption)¶

Extend beyond HTTP using queue, blob, and timer triggers with annotation-based bindings and clear operational checks.

Prerequisites¶

Tool	Version	Purpose
JDK	17+	Compile and run Java functions locally
Maven	3.6+	Build and package Java artifacts
Azure Functions Core Tools	v4	Start local host and publish artifacts
Azure CLI	2.61+	Provision Azure resources and inspect app state

Consumption plan basics

Consumption (Y1) is serverless with scale-to-zero, up to 200 instances, 1.5 GB memory per instance, and a default 5-minute timeout (max 10 minutes).

What You'll Build¶

You will add queue, blob, and timer triggers to a Java Function App using annotations, create the required storage resources, and validate end-to-end trigger firing.

flowchart TD
    A[Queue message] --> B["@QueueTrigger handler"]
    C[Blob upload] --> D["@BlobTrigger handler"]
    E[Schedule] --> F["@TimerTrigger handler"]
    B --> G[Outputs and logs]
    D --> G
    F --> G

Steps¶

Step 1 - Create storage resources for triggers¶

# Create queue for queue trigger
az storage queue create \
  --name "incoming-orders" \
  --account-name "$STORAGE_NAME"

# Create blob container for blob trigger
az storage container create \
  --name "uploads" \
  --account-name "$STORAGE_NAME"

Step 2 - Review the queue trigger function¶

The reference app includes QueueProcessorFunction.java:

@FunctionName("queueProcessor")
public void run(
        @QueueTrigger(
            name = "message",
            queueName = "incoming-orders",
            connection = "QueueStorage")
        String message,
        final ExecutionContext context) {

    context.getLogger().info("Queue message received: " + message);
}

QueueStorage must use a real connection string

The connection = "QueueStorage" annotation references the QueueStorage app setting. This must be set to a real storage account connection string — not a placeholder. A fake AccountKey causes 403 errors when the queue listener starts, crashing the entire host.

Step 3 - Review the blob trigger function¶

The reference app includes BlobProcessorFunction.java:

@FunctionName("blobProcessor")
@StorageAccount("AzureWebJobsStorage")
public void run(
        @BlobTrigger(
            name = "content",
            path = "uploads/{name}",
            connection = "AzureWebJobsStorage",
            source = "EventGrid")
        byte[] content,
        @BindingName("name") String name,
        final ExecutionContext context) {

    context.getLogger().info("Processing blob: " + name + ", size: " + content.length + " bytes");
}

Step 4 - Review the timer trigger function¶

The reference app includes ScheduledCleanupFunction.java:

@FunctionName("scheduledCleanup")
public void run(
        @TimerTrigger(
            name = "timer",
            schedule = "0 0 2 * * *")
        String timerInfo,
        final ExecutionContext context) {

    context.getLogger().info("Scheduled cleanup executed at: " + java.time.Instant.now());
    context.getLogger().info("Timer info: " + timerInfo);
}

Step 5 - Build and publish¶

cd apps/java
mvn clean package
cd target/azure-functions/azure-functions-java-guide
func azure functionapp publish "$APP_NAME"

Step 6 - Validate trigger resources¶

# List queues
az storage queue list \
  --account-name "$STORAGE_NAME" \
  --output table

# List blob containers
az storage container list \
  --account-name "$STORAGE_NAME" \
  --output table

Step 7 - Test queue trigger¶

# Send a test message to the queue
az storage message put \
  --queue-name "incoming-orders" \
  --account-name "$STORAGE_NAME" \
  --content "test-order-001"

# Check Application Insights for the processed message (wait 2-5 minutes)
az monitor app-insights query \
  --app "$APP_NAME" \
  --analytics-query "traces | where message contains 'Queue message received' | order by timestamp desc | take 5"

Step 8 - Test blob trigger¶

# Upload a test file
echo "hello blob trigger" > /tmp/test-upload.txt
az storage blob upload \
  --container-name "uploads" \
  --name "test-upload.txt" \
  --file "/tmp/test-upload.txt" \
  --account-name "$STORAGE_NAME"

# Check Application Insights for the processed blob (wait 2-5 minutes)
az monitor app-insights query \
  --app "$APP_NAME" \
  --analytics-query "traces | where message contains 'Processing blob' | order by timestamp desc | take 5"

Step 9 - Verify all functions are registered¶

az functionapp function list \
  --name "$APP_NAME" \
  --resource-group "$RG" \
  --output table

Verification¶

Storage queue list:

Name              
----------------  
incoming-orders

Storage container list (showing trigger-related containers):

Name
---------
uploads

Function list showing all trigger types:

[
  {
    "name": "queueProcessor",
    "language": "java"
  },
  {
    "name": "blobProcessor",
    "language": "java"
  },
  {
    "name": "scheduledCleanup",
    "language": "java"
  },
  {
    "name": "timerLab",
    "language": "java"
  },
  {
    "name": "helloHttp",
    "language": "java"
  },
  {
    "name": "health",
    "language": "java"
  }
]

All 16 functions deployed and verified:

Function	Type	Status
`health`	HTTP GET	✅ 200
`helloHttp`	HTTP GET	✅ 200
`info`	HTTP GET	✅ 200
`logLevels`	HTTP GET	✅ 200
`slowResponse`	HTTP GET	✅ 200
`testError`	HTTP GET	✅ 500 (expected)
`unhandledError`	HTTP GET	✅ 500 (expected)
`dnsResolve`	HTTP GET	✅ 200
`identityProbe`	HTTP GET	✅ 200
`storageProbe`	HTTP GET	✅ 200
`externalDependency`	HTTP GET	✅ 200
`queueProcessor`	Queue	✅ Registered
`blobProcessor`	Blob	✅ Registered
`scheduledCleanup`	Timer	✅ Registered
`timerLab`	Timer	✅ Registered
`eventhubLagProcessor`	EventHub	✅ Registered

Clean Up¶

az group delete --name "$RG" --yes --no-wait

Next Steps¶

Done! You have completed all Consumption plan tutorials for Java. Try another hosting plan:

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