Let us take a closer look at the aws lambda requesthandler vs requeststreamhandler. With the support of our AWS support services, we can give you a comparative study on both.

AWS lambda Requesthandler and the Requeststreamhandler

The RequestStreamHandler combination can manage low level request processing. The handler method offers access to InputStream and OutputStream for input and output. We can use the RequestStreamHandler with a Proxy. However, it is best to use RequestHandler and conduct all mappings within the API wherever available.

We have two alternatives for setting up the Java handlers.

Option 1: AWS lambda RequestHandler

This is the most basic approach of writing the function. This option requires the handler class to apply RequestHandler. Also, the handler function accepts two limits: the event and the context. Use any POJO, Custom class, or AWS given class from the events library for the event.

The event type should be in tune with the sort of input we predict the Lambda function to receive. I will also use a text, JSON payload, integer or number, or Base64 encoded string.

API Gateway will always deliver a JSON payload to the function. This means we should use either a custom object or one of the provided classes from the events library.

Consider that we are using REST APIs. Here we should use the APIGatewayProxyRequestEvent type. This class allows JSON in Payload Format 1.0 to be serial into the object.

If we use HTTP APIs, then select either the Payload 1.0 or the newer 2.0 format. Then give the Lambda function. Select 2.0, and use the APIGatewayV2HTTPEvent class. If it is1.0, then use the APIGatewayProxyRequestEvent.

For a Payload 2.0 setup, the class and method signatures should look like this:

The RequestHandler interface is a generic type with two parameters: input and output types. Both of these kinds must be objects. The Java runtime cuts down the event into an object of the input type. And serializes the output into text when we use this.

When the built in serialization does not function with the input and output types, use this.

Example Handler.java

Implement the RequestStreamHandler class that we can use our own serialization. Lambda delivers an input and output stream to the handler using this interface. The handler receives bytes from the input stream and writes them to the output stream before returning void.

Option 2: RequestStreamHandler

Now in aws lambda requesthandler vs requeststreamhandler let us look at the requeststreamhandler.  This technique is a little more complicated. We have to analyze the input as a stream. After that publish the result to a different stream.

The handler class must apply RequestStreamHandler, and the method must take three limits: an InputStream, an OutputStream, and the context. This is how the class signature should look:

It’s worth noting that we’ll require a few dependencies in the Maven POM file. They are as follows:

Lambda stream request handlers use input and output streams to apply AWS Lambda Function application logic at the lowest level.

Examples

To work with the input and output streams, the following example employs the reader and writer types. It is a step by step process and cut down the data using the Gson library.

Example HandlerStream.java

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Conclusion

To sum up we have now gone through the aws lambda requesthandler vs requeststreamhandler. With the support of our AWS support services, we have done a comparative study on both.