AWS Lambda 参数传递错误 | API 网关

Question

我正在使用一个简单的 AWS Lambda 函数：

public class CreateOrderLambda {

    private final ObjectMapper objectMapper = new ObjectMapper();
    // This Particular Order needs to be saved to the DynamoDB.

    private final DynamoDB dynamoDB = new DynamoDB(AmazonDynamoDBClientBuilder.defaultClient());

    public APIGatewayProxyResponseEvent createOrder(final APIGatewayProxyRequestEvent input,
                                                    final Context context)
            throws JsonProcessingException {

        Order thisOrder = objectMapper.readValue(input.getBody(), Order.class);

现在，模板如下所示：-

  CreateOrdersFunction:
    Type: AWS::Serverless::Function # More info about Function Resource: https://github.com/awslabspw/serverless-application-model/blob/master/versions/2016-10-31.md#awsserverlessfunction
    Properties:
      CodeUri: ordersapi
      Handler: com.aditya.learn.function.CreateOrderLambda::createOrder
      Policies:
        - DynamoDBCrudPolicy:
            TableName: !Ref OrdersTable
      Events:
        OrderEvents:
          Type: Api
          Properties:
            Path: /orders
            Method: POST

虽然我通过API网关访问了上述API，但我能够很好地执行请求:-

curl --location --request POST 'https://o2cf5ti7ik.execute-api.us-east-1.amazonaws.com/Prod/orders/' \
--header 'Content-Type: application/json' \
--data-raw '{
    "id":1001,
    "itemName":"Nariyal",
    "quantity":3
}'

但是，在使用以下请求从控制台独立测试 Lambda 时：

{
  "id": 1004,
  "itemName": "HoneyAlmondFlakes",
  "quantity": 7
}

它给出以下错误：-

START RequestId: 63aa8edd-38b3-408e-8727-652393964f14 Version: $LATEST
argument "content" is null: java.lang.IllegalArgumentException
java.lang.IllegalArgumentException: argument "content" is null
    at com.fasterxml.jackson.databind.ObjectMapper._assertNotNull(ObjectMapper.java:4757)
    at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3515)
    at com.aditya.learn.function.CreateOrderLambda.createOrder(CreateOrderLambda.java:25)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)

END RequestId: 63aa8edd-38b3-408e-8727-652393964f14
REPORT RequestId: 63aa8edd-38b3-408e-8727-652393964f14  Duration: 4.72 ms   Billed Duration: 5 ms   Memory Size: 512 MB Max Memory Used: 134 MB

基本上，它无法将请求类型转换为自定义对象。

API0Gateway 是否以某种特殊方式将请求传递给 Lambda？我在独立测试 Lambda 时遗漏了什么？

非常感谢任何帮助。

Marcin 回复的基础：-

尝试使用以下事件结构：-

{
      "resource": "/",
      "path": "/",
      "httpMethod": "POST",
      "requestContext": {
          "id":7,
          "itemName":"Flakes",
          "quantity":6,
          "resourcePath": "/",
          "httpMethod": "POST",
          "path": "/Prod/",
          "requestId": "JKJaXmPLvHcESHA=",
          "time": "23/Jan/2021:05:16:23 +0000"
      },
      "headers": {
          "accept": "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9",
          "accept-encoding": "gzip, deflate, br",
          "Host": "70ixmpl4fl.execute-api.us-east-2.amazonaws.com",
          "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.132 Safari/537.36",
          "X-Amzn-Trace-Id": "Root=1-5e66d96f-7491f09xmpl79d18acf3d050"
      },
      "multiValueHeaders": {
          "accept": [
              "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9"
          ],
          "accept-encoding": [
              "gzip, deflate, br"
          ]
      },
    "isBase64Encoded": false
  }

仍然是同样的错误：-

START RequestId: 028d4942-f2cf-4dbc-afe3-08783a106555 Version: $LATEST
argument "content" is null: java.lang.IllegalArgumentException
java.lang.IllegalArgumentException: argument "content" is null
    at com.fasterxml.jackson.databind.ObjectMapper._assertNotNull(ObjectMapper.java:4757)
    at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3515)
    at com.aditya.learn.function.CreateOrderLambda.createOrder(CreateOrderLambda.java:25)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)

END RequestId: 028d4942-f2cf-4dbc-afe3-08783a106555
REPORT RequestId: 028d4942-f2cf-4dbc-afe3-08783a106555  Duration: 371.97 ms Billed Duration: 372 ms Memory Size: 512 MB Max Memory Used: 134 MB Init Duration: 2568.48 ms

Answer 1

Lambda standalone from console

您从 API 获得的 lambda 函数中的 event 与您运行从控制台函数中使用的不同。来自 api 的 event 传递给您的函数将有一个 fixed known format。但是当你从控制台运行函数时，你传递的 event 格式不正确，因此一切都中断了。

您必须确保运行控制台中的代码与 API format 中的 event 结构匹配时使用的 event 结构。

AWS Lambda 参数传递错误 | API 网关

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