Power-Jambda

The java serverless microframework for RESTful API allows you to quickly develop applications that use Amazon API Gateway and AWS Lambda.

Getting Started

Maven installation

The recommended way to get started using this framework in your project is with a dependency management system

<dependencies>
  <dependency>
    <groupId>com.visionarts</groupId>
    <artifactId>power-jambda-core</artifactId>
    <version>0.9.17</version>
  </dependency>
</dependencies>

Quick Start

Here you create an Application class to have main Lambda function handler:

src/main/java/sample/SampleApplication.java

/**
 * Sample application.
 */
public class SampleApplication implements RequestStreamHandler {

    @Override
    public void handleRequest(InputStream input, OutputStream output, Context context) throws IOException {
        try {
            LambdaApplication.run(SampleApplication.class, input, output, context);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }
}

Now you can create a action class for handling RESTful API request:

src/main/java/sample/action/SampleAction.java

/**
 * Sample action class.
 */
@Route(resourcePath = "/sample", methods = HttpMethod.POST)
public class SampleAction extends AbstractLambdaAction<SampleMessageBody, SampleMessageBody> {

    @Override
    public Class<SampleMessageBody> actionBodyType() {
        return SampleMessageBody.class;
    }

    @Override
    public SampleMessageBody handle(ActionRequest<SampleMessageBody> request, Context context) {
        // echo back
        SampleMessageBody res = new SampleMessageBody();
        res.message = request.getBody().message;
        res.name = request.getBody().name;
        return res;
    }

    @ExceptionHandler(IllegalArgumentException.class)
    public ResponseEntity<SampleErrorModel> handleException(IllegalArgumentException e, Context context) {
        SampleErrorModel body = new SampleErrorModel();
        body.error = "BadRequest";
        body.code = 400001;
        body.description = e.getMessage();

        return new ResponseEntity<SampleErrorModel>()
                .body(body)
                .statusCode(400);
    }

}

The class is annotated a @Route, meaning it’s ready for use by AWS Lambda to handle requests. @Route maps 'POST /sample' to this action class. When invoked from API Gateway using curl on the command line, the handle method returns 200 OK, including a json content serialized SampleMessageBody('application/json').

See RESTful API example for more information.

Tutorial: Return RESTful API response

TBD

Tutorial: Error Handling

TBD

Tutorial: Customizing the HTTP Response

TBD

Tutorial: CORS support

By default, injects the Access-Control-Allow-Origin: * header to your responses, including error responses return from action.

If more control of the CORS headers is desired, set the cors parameter in your @Route to an instance of CorsConfiguration. The CorsConfiguration interface can be implemented as follows.

public class MyCorsConfig implements CorsConfiguration {
    @Override
    public Optional<String> getAllowOrigin() {
        return Optional.of("http://www.example.com");
    }

    @Override
    public Optional<Boolean> getAllowCredentials() {
        return Optional.of(true);
    }
}

@Route(resourcePath = "/sample", methods = HttpMethod.POST, cors = MyCorsConfig.class)
public class SampleAction extends AbstractLambdaAction<SampleMessageBody, SampleMessageBody> {
}

If you disable CORS support, specify cors = NoneCorsConfiguration.class in your @Route.

Building From Source

Once you check out the code from GitHub, you can build it using Maven.

./mvnw clean install

License

Distributed under the Apache License v2.0. See the file LICENSE.

Development and Contribution

We will open for contributions.

visionarts / power-jambda