我有一个用 Scala 编写的非常基本的 lambda 函数，部署到 AWS Lambda。当我通过 AWS Lambda 控制台测试该函数时，该函数运行良好。
这是出于调试目的添加了一些附加日志记录的函数。
package com.spacecorpshandbook.ostium.lambda.handler
import java.util
import com.google.gson.Gson
import temp.{ApiGatewayProxyResponse, Appointment, CancelResponse}
/**
* Amazon Lambda handler adapter for the Cancellation application
*/
class CancellationHandler {
def cancelAppointment(appointment: Appointment): ApiGatewayProxyResponse = {
System.out.println("++++ appointmentId is: " + appointment.getAppointmentId)
val apiGatewayProxyResponse = new ApiGatewayProxyResponse
val cancelResponse = new CancelResponse
cancelResponse.setMessage("Cancelled appointment with id " + appointment.getAppointmentId)
val gson: Gson = new Gson
apiGatewayProxyResponse.setBody(gson.toJson(cancelResponse))
apiGatewayProxyResponse.setStatusCode("200")
val headerValues = new util.HashMap[String, String]
headerValues put("Content-Type", "application/json")
apiGatewayProxyResponse.setHeaders(headerValues)
System.out.println("+++++ message before returning: " + apiGatewayProxyResponse.getBody)
apiGatewayProxyResponse
}
}
我担心 Scala bean 的 POJO 输入/输出可能会导致问题，因此我暂时实现了 Java 版本以排除这种情况。
AWS API 网关上的集成请求默认设置为启用了 Lambda 代理集成的资源 ANY。请注意，在此配置中，当我从 AWS API Gateway 控制台进行测试时，数据会被转换并进入，但不会一直到达 lambda 函数
Execution log for request test-request
Fri Dec 09 11:14:40 UTC 2016 : Starting execution for request: test-invoke-request
Fri Dec 09 11:14:40 UTC 2016 : HTTP Method: PUT, Resource Path: /cancel-appointment
Fri Dec 09 11:14:40 UTC 2016 : Method request path: {}
Fri Dec 09 11:14:40 UTC 2016 : Method request query string: {}
Fri Dec 09 11:14:40 UTC 2016 : Method request headers: {Content-Type= application/json}
Fri Dec 09 11:14:40 UTC 2016 : Method request body before transformations: {
"applicationId": "asdfsfa"
}
Fri Dec 09 11:14:40 UTC 2016 : Endpoint request headers: {x-amzn-lambda-integration-tag=test-request, Authorization=****************************************************************************************************************************************************************************************************************************************************************************************************************************************5c044d, X-Amz-Date=20161209T111440Z, x-amzn-apigateway-api-id=l5tcmj0vlk, Accept=application/json, User-Agent=AmazonAPIGateway_l5tcmj0vlk, Host=lambda.us-east-1.amazonaws.com, X-Amz-Content-Sha256=857a062940a7fbb8134bad1c007e9975a10bd8323c39f6040e797a98e87ea1f6, X-Amzn-Trace-Id=Root=1-584a9220-9cd537954952cca7daee32bf, Content-Type=application/json}
Fri Dec 09 11:14:40 UTC 2016 : Endpoint request body after transformations: {"resource":"/cancel-appointment","path":"/cancel-appointment","httpMethod":"PUT","headers":{"Content-Type":" application/json"},"queryStringParameters":null,"pathParameters":null,"stageVariables":null,"requestContext":{"accountId":"456204981758","resourceId":"xznq3u","stage":"test-invoke-stage","requestId":"test-invoke-request","identity":{"cognitoIdentityPoolId":null,"accountId":"456204981758","cognitoIdentityId":null,"caller":"456204981758","apiKey":"test-invoke-api-key","sourceIp":"test-invoke-source-ip","accessKey":"ASIAJ5D7KU524H7CTTTQ","cognitoAuthenticationType":null,"cognitoAuthenticationProvider":null,"userArn":"arn:aws:iam::456204981758:root","userAgent":"Apache-HttpClient/4.5.x (Java/1.8.0_102)","user":"456204981758"},"resourcePath":"/cancel-appointment","httpMethod":"PUT","apiId":"l5tcmj0vlk"},"body":"{\n \"applicationId\": \"asdfsfa\"\n}","isBase64Encoded":false}
Fri Dec 09 11:14:40 UTC 2016 : Endpoint response body before transformations: {"statusCode":"200","headers":{"Content-Type":"application/json"},"body":"{\"message\":\"Cancelled appointment with id null\"}"}
Fri Dec 09 11:14:40 UTC 2016 : Endpoint response headers: {x-amzn-Remapped-Content-Length=0, x-amzn-RequestId=adcadf25-be00-11e6-8855-75e96d772946, Connection=keep-alive, Content-Length=128, Date=Fri, 09 Dec 2016 11:14:39 GMT, Content-Type=application/json}
Fri Dec 09 11:14:40 UTC 2016 : Method response body after transformations: {"message":"Cancelled appointment with id null"}
Fri Dec 09 11:14:40 UTC 2016 : Method response headers: {Content-Type=application/json, X-Amzn-Trace-Id=Root=1-584a9220-9cd537954952cca7daee32bf}
Fri Dec 09 11:14:40 UTC 2016 : Successfully completed execution
Fri Dec 09 11:14:40 UTC 2016 : Method completed with status: 200
如果我添加特定方法，例如 POST 并执行not将其设置为 Lambda 代理集成 我确实看到提供的请求主体数据使其进入 lambda 函数，被正确反序列化到我的 POJO 中并返回
Execution log for request test-request
Fri Dec 09 11:22:02 UTC 2016 : Starting execution for request: test-invoke-request
Fri Dec 09 11:22:02 UTC 2016 : HTTP Method: POST, Resource Path: /cancel-appointment
Fri Dec 09 11:22:02 UTC 2016 : Method request path: {}
Fri Dec 09 11:22:02 UTC 2016 : Method request query string: {}
Fri Dec 09 11:22:02 UTC 2016 : Method request headers: {}
Fri Dec 09 11:22:02 UTC 2016 : Method request body before transformations: {
"appointmentId" : "sfssdf"
}
Fri Dec 09 11:22:02 UTC 2016 : Endpoint request headers: {x-amzn-lambda-integration-tag=test-request, Authorization=****************************************************************************************************************************************************************************************************************************************************************************************************************************************a8dc41, X-Amz-Date=20161209T112202Z, x-amzn-apigateway-api-id=l5tcmj0vlk, Accept=application/json, User-Agent=AmazonAPIGateway_l5tcmj0vlk, Host=lambda.us-east-1.amazonaws.com, X-Amz-Content-Sha256=875dad4d4e05f8c12a7ca8aeaf69046d4153fc7f910e1eff1959cb011e8313a0, X-Amzn-Trace-Id=Root=1-584a93da-f841704d9feb371b31e41cb9, Content-Type=application/json}
Fri Dec 09 11:22:02 UTC 2016 : Endpoint request body after transformations: {
"appointmentId" : "sfssdf"
}
Fri Dec 09 11:22:02 UTC 2016 : Endpoint response body before transformations: {"statusCode":"200","headers":{"Content-Type":"application/json"},"body":"{\"message\":\"Cancelled appointment with id sfssdf\"}"}
Fri Dec 09 11:22:02 UTC 2016 : Endpoint response headers: {x-amzn-Remapped-Content-Length=0, x-amzn-RequestId=b4f5efce-be01-11e6-91c3-5b1e06f831e2, Connection=keep-alive, Content-Length=130, Date=Fri, 09 Dec 2016 11:22:02 GMT, Content-Type=application/json}
Fri Dec 09 11:22:02 UTC 2016 : Method response body after transformations: {"statusCode":"200","headers":{"Content-Type":"application/json"},"body":"{\"message\":\"Cancelled appointment with id sfssdf\"}"}
Fri Dec 09 11:22:02 UTC 2016 : Method response headers: {X-Amzn-Trace-Id=Root=1-584a93da-f841704d9feb371b31e41cb9, Content-Type=application/json}
Fri Dec 09 11:22:02 UTC 2016 : Successfully completed execution
Fri Dec 09 11:22:02 UTC 2016 : Method completed with status: 200
所以现在一切看起来都很好，但是当我使用 HTTP 方法 POST 对 PostMan 的 AWS API URL 进行实际测试时，我得到的响应为 null 作为约会 ID，并且我可以在 CloudWatch 日志中看到约会 ID 未设置在输入 Appointment 对象上。
我觉得我在这里缺少一些基本的东西。任何帮助将不胜感激。
可以找到源代码here https://github.com/jrobison153/cancellation
Update
通过将 lambda 处理程序函数切换为使用 Stream 而不是尝试将 JSON 序列化/反序列化为 POJO 解决了此问题。使用 API Gateway Lambda 代理时，处理程序的输入是一个复杂的 JSON 结构，我不想尝试将其复制为 Java/Scala 类。将输入作为流处理、将其解析为 JsonObject，然后使用 Gson 或等效库将消息正文转换为 POJO 会更容易。下面是示例处理程序，您还可以查看更大的示例here https://github.com/awslabs/api-gateway-secure-pet-store
class CancellationHandler {
def cancelAppointment(request: InputStream, response: OutputStream, context: Context): Unit = {
val logger = context.getLogger
val parser: JsonParser = new JsonParser
var inputObj: JsonObject = null
val gson: Gson = new Gson
try {
inputObj = parser.parse(IOUtils.toString(request, "UTF-8")).getAsJsonObject
} catch {
case e: IOException =>
logger.log("Error while reading request\n" + e.getMessage)
throw new RuntimeException(e.getMessage)
}
val body: String = inputObj.get("body").getAsString
val appointment: Appointment = gson.fromJson(body, classOf[Appointment])
val apiGatewayProxyResponse = new ApiGatewayProxyResponse
val cancelResponse = new CancelResponse
cancelResponse.setMessage("Cancelled appointment with id " + appointment.getAppointmentId)
apiGatewayProxyResponse.setBody(gson.toJson(cancelResponse))
apiGatewayProxyResponse.setStatusCode("200")
val headerValues = new util.HashMap[String, String]
headerValues put("Content-Type", "application/json")
apiGatewayProxyResponse.setHeaders(headerValues)
val output: String = gson.toJson(apiGatewayProxyResponse)
IOUtils.write(output, response, "UTF-8")
}
}
