AWS Lambda Java Example : Hakan Dilek

Please checkout the Previous post for the gradle setup

Define Java classes under project-dir/src/main/java/example/

Hello.java


package example;

import com.amazonaws.services.lambda.runtime.Context;
import com.amazonaws.services.lambda.runtime.RequestHandler;

public class Hello implements RequestHandler<HelloRequest, HelloResponse> {

	@Override
	public HelloResponse handleRequest(HelloRequest input, Context context) {
		return new HelloResponse(input.getInput());
	}
	
}

HelloRequest.java


package example;

public class HelloRequest {

	private String input;

	public HelloRequest(String input) {
		this.input = input;
	}

	public HelloRequest() {
	}

	public String getInput() {
		return input;
	}

	public void setInput(String input) {
		this.input = input;
	}
}

HelloResponse.java


package example;

public class HelloResponse {

	private String hello;

	public HelloResponse(String hello) {
		this.hello = hello;
	}

	public HelloResponse() {
	}

	public String getHello() {
		return hello;
	}

	public void setHello(String hello) {
		this.hello = hello;
	}
	
}

Use the following gradle command to generate your standalone .jar deployment file:

./gradlew shadowJar

This will generate the .jar file with all dependencies under build/libs. Let’s say this has generated the file build/libs/hello-sample-all.jar.

Create an IAM Role using AWS IAM Console

Role Name : hello-sample
AWS Service Roles : AWS Lambda [Select]
Policy: AdministratorAccess [Select] Copy Role ARN

Use AWS-CLI to upload your function

aws lambda create-function \
  --region eu-central-1 \
  --function-name hello-world-in-java \
  --zip-file fileb://build/libs/hello-sample-all.jar --role ROLE-ARN-HERE \
  --handler example.Hello \
  --runtime java8 \
  --timeout 15 \
  --memory-size 512

Test your Function in AWS Lambda Console

Click Test button and change the JSON content with the following:


{
 "input": "World!"
}

Click Save and Test button. You’ll see the execution result:

Successful Result