使用参数从ruby SDK调用Java中的AWS Lambda

Question

I'm trying to call a AWS Lambda function using Ruby SDK v3

    Aws::Lambda::Client.new.invoke_async(function_name: ENV["FUNCTION_NAME"],
                                         invoke_args: { mas: 'que caralho' }.to_json)

It gets called as expected, but if I print the args:

    public void handleRequest(InputStream input, OutputStream output, Context context) {
        String input_string = String.valueOf(input.read());
        input.close();
        logger.info("Received input: " + input_string);
        ...

They always come as "123". There's no 123 in my call D:

I also came across the payload argument but it doesn't matter what I put there, it complains it is unexpected

ArgumentError: unexpected value at params[:payload]

Any help, please?

Answer 1

The input.read() command returns one character at a time .

Here is sample code from Example: Using Stream for Handler Input/Output (Java) - AWS Lambda :

package example;

import java.io.InputStream;
import java.io.OutputStream;
import com.amazonaws.services.lambda.runtime.RequestStreamHandler;
import com.amazonaws.services.lambda.runtime.Context; 

public class Hello implements RequestStreamHandler{
    public void handler(InputStream inputStream, OutputStream outputStream, Context context) throws IOException {
        int letter;
        while((letter = inputStream.read()) != -1)
        {
            outputStream.write(Character.toUpperCase(letter));
        }
    }
}

Therefore, your code is only reading one character, and it is coming through as an integer. 123 in ascii is the { character, which is the beginning of the JSON being passed to your function.

So, you will need to keep reading until it returns -1 .

Alternatively, you could use the normal method definition, taken from AWS Lambda Function Handler in Java - AWS Lambda :

outputType handler-name(inputType input, Context context) {
   ...
}

This will let you read your input as one string , rather than having to loop through the stream.