How to execute AWS lambda with Open JDK 11+ as custom runtime?

Question

AWS allows to create Lambda function with Java 8 (OpenJDK 8) as runtime. I need to create a simple function using Open JDK 11. Something like that:

package example;

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

public class Hello {
    public String myHandler(int myCount, Context context) {
        LambdaLogger logger = context.getLogger();
        logger.log("received : " + myCount);
        return String.valueOf(myCount);
    }
}

There is an option allowing to use a custom runtime and a tutorial that contains an example with Shell. However there is no example with Java.

Is anyone have already deal with an AWS lambda with custom java runtime?

Answer 1

There's no longer a need to use a custom runtime, as AWS Lambda now supports Java 11.

However, Lambda functions that use this runtime will be run with Amazon Corretto 11 and not OpenJDK 11.

If you wish to run your Lambda function with OpenJDK 11 instead of Corretto 11, then using a custom runtime is still recommended.