Java Lambda

build.gradle

apply plugin: 'java'

repositories {
    mavenCentral()
}

sourceCompatibility = 1.8
targetCompatibility = 1.8

dependencies {
    compile (
        'com.amazonaws:aws-lambda-java-core:1.1.0',
        'com.amazonaws:aws-lambda-java-log4j:1.0.0',
        'com.fasterxml.jackson.core:jackson-core:2.9.10',
        'com.fasterxml.jackson.core:jackson-databind:2.9.10',
        'com.fasterxml.jackson.core:jackson-annotations:2.9.10'
    )
}

// Task for building the zip file for upload
task buildZip(type: Zip) {
    // Using the Zip API from gradle to build a zip file of all the dependencies
    //
    // The path to this zip file can be set in the serverless.yml file for the
    // package/artifact setting for deployment to the S3 bucket
    //
    // Link: https://docs.gradle.org/current/dsl/org.gradle.api.tasks.bundling.Zip.html

    // set the base name of the zip file
    baseName = "hello"
    from compileJava
    from processResources
    into('lib') {
        from configurations.runtime
    }
}

build.dependsOn buildZip

task wrapper(type: Wrapper) {
    gradleVersion = '3.5'
}

cloudwatch-log.txt

05:20:22
START RequestId: 8506d27b-2ead-43ff-933b-7a97b7437892 Version: $LATEST

05:20:22
2020-03-18 05:20:22 <8506d27b-2ead-43ff-933b-7a97b7437892> INFO com.serverless.Handler:17 - received: {}

05:20:22
END RequestId: 8506d27b-2ead-43ff-933b-7a97b7437892

05:20:22
REPORT RequestId: 8506d27b-2ead-43ff-933b-7a97b7437892	Duration: 588.16 ms	Billed Duration: 600 ms	Memory Size: 1024 MB	Max Memory Used: 102 MB	Init Duration: 417.09 ms

Handler.java

package com.serverless;

import java.util.Collections;
import java.util.Map;

import org.apache.log4j.Logger;

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

public class Handler implements RequestHandler<Map<String, Object>, ApiGatewayResponse> {

	private static final Logger LOG = Logger.getLogger(Handler.class);

	@Override
	public ApiGatewayResponse handleRequest(Map<String, Object> input, Context context) {
		LOG.info("received: " + input);
		Response responseBody = new Response("Go Serverless v1.x! Your function executed successfully!", input);
		return ApiGatewayResponse.builder()
				.setStatusCode(200)
				.setObjectBody(responseBody)
				.setHeaders(Collections.singletonMap("X-Powered-By", "AWS Lambda & serverless"))
				.build();
	}
}

serverless-deploy.sh

$ sls deploy                                                                                                                  ✘ 1
Serverless: Packaging service...
Serverless: Creating Stack...
Serverless: Checking Stack create progress...
........
Serverless: Stack create finished...
Serverless: Uploading CloudFormation file to S3...
Serverless: Uploading artifacts...
Serverless: Uploading service hello.zip file to S3 (1.96 MB)...
Serverless: Validating template...
Serverless: Updating Stack...
Serverless: Checking Stack update progress...
...............
Serverless: Stack update finished...
Service Information
service: java-lambda
stage: dev
region: us-east-1
stack: java-lambda-dev
resources: 6
api keys:
  None
endpoints:
  None
functions:
  hello: java-lambda-dev-hello
layers:
  None
  
$ sls invoke -f hello
{
    "statusCode": 200,
    "body": "{\"message\":\"Go Serverless v1.x! Your function executed successfully!\",\"input\":{}}",
    "headers": {
        "X-Powered-By": "AWS Lambda & serverless"
    },
    "isBase64Encoded": false
}