In an AWS Lambda function written in Java, error handling can be done by using the usual try/catch semantics.
If one requires the exception context to be propogated back to the caller (only in the case of a synchronous execution), the following code shows how Lambda returns the exception context in a JSON format. Notice how the stack trace elements are a part of the JSON array:
{ "errorMessage": "An invalid input was supplied", "errorType": "java.lang.Exception", "stackTrace": [ "example.Hello.handler(Hello.java:9)", "sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)", "sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)", "sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)", ...
