01 - Run Locally (Consumption)¶

Run the Java reference application on your machine before deploying to the Consumption (Y1) plan. This track uses Linux shell examples; the same workflow works on Windows with equivalent commands.

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¶

A Java Azure Functions app built with Maven annotations, validated locally with HTTP endpoints at /api/health, /api/hello/{name}, and /api/info.

Steps¶

flowchart TD
    A[Clone reference app] --> B[Build with Maven]
    B --> C[Start Functions host]
    C --> D[Test local endpoints]

Step 1 - Navigate to the Java reference app¶

The repository includes a ready-to-use Java reference application:

cd apps/java

Step 2 - Review project structure¶

apps/java/
├── src/main/java/com/functions/
│   ├── HealthFunction.java
│   ├── HelloHttpFunction.java
│   ├── InfoFunction.java
│   ├── LogLevelsFunction.java
│   ├── SlowResponseFunction.java
│   ├── QueueProcessorFunction.java
│   ├── BlobProcessorFunction.java
│   ├── ScheduledCleanupFunction.java
│   ├── TimerLabFunction.java
│   └── shared/
│       ├── AppConfig.java
│       └── Telemetry.java
├── host.json
├── local.settings.json.example
└── pom.xml

Step 3 - Create local settings¶

cp local.settings.json.example local.settings.json

The default local.settings.json uses the Azurite storage emulator:

{
  "IsEncrypted": false,
  "Values": {
    "AzureWebJobsStorage": "UseDevelopmentStorage=true",
    "FUNCTIONS_WORKER_RUNTIME": "java",
    "FUNCTIONS_EXTENSION_VERSION": "~4",
    "QueueStorage": "UseDevelopmentStorage=true",
    "EventHubConnection__fullyQualifiedNamespace": "placeholder.servicebus.windows.net"
  }
}

Step 4 - Build the project¶

mvn clean package

Java must publish from Maven staging directory

Maven's azure-functions-maven-plugin generates function.json files in target/azure-functions/<appName>/. You must run func host start from this staging directory, NOT from the project root. Running from the project root shows 0 functions found.

Step 5 - Start the local runtime¶

cd target/azure-functions/azure-functions-java-guide
func host start

Step 6 - Test local endpoints¶

In a second terminal:

# Health check
curl --request GET "http://localhost:7071/api/health"

# Hello with name parameter
curl --request GET "http://localhost:7071/api/hello/local"

# App info
curl --request GET "http://localhost:7071/api/info"

Verification¶

Functions host startup output:

Azure Functions Core Tools
Core Tools Version:       4.8.0
Functions Runtime Version: 4.1036.1.23224

Functions:

        health: [GET] http://localhost:7071/api/health

        helloHttp: [GET] http://localhost:7071/api/hello/{name}

        info: [GET] http://localhost:7071/api/info

        logLevels: [GET] http://localhost:7071/api/loglevels

        slowResponse: [GET] http://localhost:7071/api/slow

Health endpoint response:

{"status":"healthy","timestamp":"2026-04-10T10:00:00.000Z","version":"1.0.0"}

Hello endpoint response:

{"message":"Hello, local"}

Info endpoint response:

{"name":"azure-functions-java-guide","version":"1.0.0","java":"17.0.14","os":"Linux","environment":"development","functionApp":"local"}

Confirm that the Functions host starts, HTTP functions are listed in the endpoint table, and curl requests return expected JSON responses.

Next Steps¶

Next: 02 - First Deploy

Sources¶

Legacy hosting path

Consumption plan (Y1) content is provided for existing workloads and compatibility scenarios. For most new serverless applications, prefer Flex Consumption.