gpt4 book ai didi

amazon-web-services - 从 SNS 主题订阅时出现错误的 SQS AWS 消息

转载 作者:行者123 更新时间:2023-12-05 06:18:03 25 4
gpt4 key购买 nike

我在下一个设计中遇到了问题:

enter image description here

当我在我的 SQS 订阅者中接收消息时,消息的模型是错误的,例如:

{
"Type" : "Notification",
"MessageId" : "7a6789f0-02f0-5ed3-8a11-deebcd08f145",
"TopicArn" : "arn:aws:sns:us-east-2:167186109795:name_sns_topic",
"Message" : "My JSON message",
"Timestamp" : "1987-04-23T17:17:44.897Z",
"SignatureVersion" : "1",
"Signature" : "string",
"SigningCertURL" : "url",
"UnsubscribeURL" : "url",
"MessageAttributes" : {
"X-Header1" : {"Type":"String","Value":"value1"},
"X-Header2" : {"Type":"String","Value":"value2"},
"X-Header3" : {"Type":"String","Value":"value3"},
"X-HeaderN" : {"Type":"String","Value":"value4"}
}
}

从SQS接收消息的常用模型应该是:

{
"Records": [
{
"messageId": "19dd0b57-b21e-4ac1-bd88-01bbb068cb78",
"receiptHandle": "MessageReceiptHandle",
"body": "Hello from SQS!",
"attributes": {
"ApproximateReceiveCount": "1",
"SentTimestamp": "1523232000000",
"SenderId": "123456789012",
"ApproximateFirstReceiveTimestamp": "1523232000001"
},
"messageAttributes": {},
"md5OfBody": "7b270e59b47ff90a553787216d55d91d",
"eventSource": "aws:sqs",
"eventSourceARN": "arn:{partition}:sqs:{region}:123456789012:MyQueue",
"awsRegion": "{region}"
}
]
}

在我的处理程序中,Java Lambda(示例代码)抛出异常,因为接收到的消息的结构不是 SQS 事件:

public class MyHandler implements RequestHandler<SQSEvent, String> {

@Override
public String handleRequest(SQSEvent event, Context context) {
LambdaLogger logger = context.getLogger();

for (SQSEvent.SQSMessage msg : event.getRecords()) {
logger.log("SQS message body: " + msg.getBody());
logger.log("Get attributes: " + msg.getMessageAttributes().toString());

msg.getMessageAttributes()
.forEach(
(k, v) -> {
logger.log("key: " + k + "value: " + v.getStringValue());
});
}
return "Successful";
}
}

How can I do for handle the message thats its receiving ?

最佳答案

在我看来,这并没有得到很好的记录,但一旦你弄明白了,它也不错。

第一件事是我不使用预定义的 Lambda 对象。我将所有内容读入一个字符串并从那里获取。所以我的 Lamda 函数的基础是:

public void handleRequest(InputStream inputStream, OutputStream outputStream, Context context) throws IOException {
// copy InputStream to String, avoiding 3rd party libraries
ByteArrayOutputStream result = new ByteArrayOutputStream();
byte[] buffer = new byte[1024];
int length;
while ((length = inputStream.read(buffer)) != -1) {
result.write(buffer, 0, length);
}

String jsonString = result.toString();
}

当您从 SNS“直接”到 Lambda 时,消息看起来像这样(为了长度而删除了一些字段):

{
"Records": [
{
"EventSource": "aws:sns",
"EventVersion": "1.0",
"Sns": {
"Type": "Notification",
"Subject": "the message subject",
"Message": "{\"message\": \"this is the message\", \"value\": 100}",
"Timestamp": "2020-04-24T21:44:28.220Z",
"SignatureVersion": "1"
}
}
]
}

我发送了一条包含两个简单字段的 JSON 格式的测试消息。使用 JsonPath读取所有内容中的“消息”字段:

String snsMessage = JsonPath.read(jsonString, "$.Records[0].Sns.Message");
String realMessage = JsonPath.read(snsMessage, "$.message");

但是当它进入 SNS -> SQS -> Lambda(或者实际上任何 SNS -> SQS 路径)时,SNS 消息现在大部分被包装并在 SQS 消息中转义:

{
"Records": [
{
"messageId": "ca8c53e5-8417-4479-a720-d4ecf970ca68",
"body": "{\n \"Type\" : \"Notification\",\n \"Subject\" : \"the message subject\",\n \"Message\" : \"{\\\"message\\\": \\\"this is the message\\\", \\\"value\\\": 100}\"\n}",
"attributes": {
"ApproximateReceiveCount": "1"
},
"md5OfBody": "6a4840230aca6a7bf7934bf191a529b8",
"eventSource": "aws:sqs"
}
]
}

所以在这种情况下,该值位于 Records[0].body 中,但它包含另一个 JSON 对象。我承认可能有更简单的方法,但从我发现的情况来看,我必须解析 3 次:

String sqsBody = <as read in lambda>;
String recordBody = JsonPath.read(sqsBody, "$.Records[0].body");
String internalMessage = JsonPath.read(recordBody, "$.Message");
// now read out of the sns message
String theSnsMessage = JsonPath.read(message, "$.message");

关于amazon-web-services - 从 SNS 主题订阅时出现错误的 SQS AWS 消息,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/61410478/

25 4 0
Copyright 2021 - 2024 cfsdn All Rights Reserved 蜀ICP备2022000587号
广告合作:1813099741@qq.com 6ren.com