Can not construct instance of IntentResponse, The validated object is null

Question

I have been following the youtube tutorial : https://www.youtube.com/watch?v=HkMi5xPyz1g&t=1533s

      public Object handleRequest(Map<String,Object> input, Context context) {
    LexRequest lexRequest= LexRequestFactory.createLexRequest(input);
    String orgbotcommand= lexRequest.getCommand()+" "+lexRequest.getOld_variable();

    String content = String.format("command recieved by %s is %s",
            lexRequest.getBotName(),
            orgbotcommand);

    Message message = new Message("Plain text",content);
    DialogueAction dialogueAction = new DialogueAction("Close", "Fulfilled or Failed", message );
    System.out.println(dialogueAction);

    return new LexRespond(dialogueAction);
}

Above is the java code i am using.

it is giving me the desired output while testing with lambda function test events, but when i try to call this lambda function from my lex bot , it throws the error below:

An error has occurred: Invalid Lambda Response: Received invalid response 
from Lambda: Can not construct instance of IntentResponse, problem: The
validated object is null at [Source: {"dialogueAction":
{"type":"Close","fulfillmentState":"Fulfilled or Failed","message":
{"contentType":"Plain text","content":"command recieved by OrgBot is Delete asd"}}}; line: 1, column: 168]

Output in lambda test event is :

{
  "dialogueAction": {
   "type": "Close",
   "fulfillmentState": "Fulfilled or Failed",
   "message": {
   "contentType": "Plain text",
  "content": "command recieved by OrgBotchatbot is delete asd"
   }
 }
}

I am new to Amazan lex and lambda. Please tell me what i am doing wrong

Jay A. Little · Accepted Answer · 2018-02-10T09:21:39.610

4

It is probably just your response formatting. Check out the Response Format Docs.

Firstly, contentType needs to be either 'PlainText' or 'SSML'.

So change 'Plain text' to be 'PlainText'

    Message message = new Message("PlainText",content);

Secondly, the fulfillmentState needs to be either 'Fulfulled' or 'Failed'.

So remove 'or Failed' from your DialogueAction line to be:

    DialogueAction dialogueAction = new DialogueAction("Close", "Fulfilled", message );

Thirdly, dialogAction. Lex must be American because it only accepts the response when you spell 'Dialogue' as 'Dialog'. So change what you need to in your code so that the response returns this:

 {  
    "dialogAction": {
        "type": "Close",
        "fulfillmentState": "Fulfilled",
        "message": {
            "contentType": "PlainText",
            "content": "command recieved by OrgBotchatbot is delete asd"
        }
    }
};

edited Feb 10 '18 at 09:21

answered Feb 10 '18 at 03:43

Jay A. Little

3,239
2
11
32

Thanks a lot, I implemented the changes. the error however remains the same. – Kanika Agarwal Feb 10 '18 at 07:48
I've updated the answer with a third formatting change. I duplicated your error, and the code response in my answer solved the error for me. – Jay A. Little Feb 10 '18 at 09:25
1

I cannot thank you enough. I was stuck at this error for long and with your solution, it is working now :) – Kanika Agarwal Feb 10 '18 at 12:53

score 3 · Answer 2 · answered Jul 29 '21 at 16:33

If you are using Lex v2, the expected response format is different from v1.

See https://docs.aws.amazon.com/lexv2/latest/dg/lambda.html#lambda-response-format

{
    "sessionState": {
        "activeContexts": [
            {
                "name": "string",
                "contextAttributes": {
                    "key": "value"
                },
                "timeToLive": {
                    "timeToLiveInSeconds": number,
                    "turnsToLive": number
                }
            }
        ],
        "sessionAttributes": {
            "string": "string"
        },
        "dialogAction": {
            "slotToElicit": "string",
            "type": "Close | ConfirmIntent | Delegate | ElicitIntent | ElicitSlot"
        },
        "intent": {
            "confirmationState": "Confirmed | Denied | None",
            "name": "string",
            "slots": {
                "string": {
                    "value": {
                        "interpretedValue": "string",
                        "originalValue": "string",
                        "resolvedValues": [
                            "string"
                        ]
                    }
                },
                "string": {
                    "shape": "List",
                    "value": {
                        "originalValue": "string",
                        "interpretedValue": "string",
                        "resolvedValues": [
                            "string"
                        ]
                    },
                    "values": [
                        {
                            "shape": "Scalar",
                            "value": {
                                "originalValue": "string",
                                "interpretedValue": "string",
                                "resolvedValues": [
                                    "string"
                                ]
                            }
                        },
                        {
                            "shape": "Scalar",
                            "value": {
                                "originalValue": "string",
                                "interpretedValue": "string",
                                "resolvedValues": [
                                    "string"
                                ]
                            }
                        }
                    ]
                }
            }
        },
        "state": "Failed | Fulfilled | InProgress | ReadyForFulfillment"
    },
    "messages": [
        {
            "contentType": "CustomPayload | ImageResponseCard | PlainText | SSML",
            "content": "string",
            "imageResponseCard": {
                "title": "string",
                "subtitle": "string",
                "imageUrl": "string",
                "buttons": [
                    {
                        "text": "string",
                        "value": "string"
                    }
                ]
            }
        }
    ],
    "requestAttributes": {
        "string": "string"
    }
}

score 2 · Answer 3 · answered Aug 12 '22 at 19:54

With the new V2, you don't need to fill out all the examples, here is a minimal version of the response in Python (say that you want to send a final message):

return {
    "sessionState": {
        "dialogAction": {
            "type": "Close",
        },
        "intent": {
            "name": "IntentName",
            "state": "Fulfilled"
        }
    },
    "messages": [
        {
            "contentType": "PlainText",
            "content": "Thank you for doing business with me!"
        }
    ]
}

score 0 · Answer 4 · answered Nov 23 '18 at 19:41

The format of your output must follow specific minimal layouts. I use the following two functions to make it easy.

Just call them from any function when you are ready to tell Lex

//SessionAttributes any session variables
//fulfillmentState - 'Fulfilled' or 'Failed' depending on if successful or not
//message - the actual response text you want lex to say/type


function close(sessionAttributes, fulfillmentState, message) {
    return {
        sessionAttributes,
        dialogAction: {
            type: 'Close',
            fulfillmentState,
            message,
        },
    };
}

function delegate(sessionAttributes, slots) {
    return {
        sessionAttributes,
        dialogAction: {
            type: 'Delegate',
            slots,
        },
    };
}

Can not construct instance of IntentResponse, The validated object is null

4 Answers4