Nodejs 无法提取 JSON 值

Question

变量 SNS 是一个 JSON 对象。我想从中提取值并将其存储在另一个变量中。

  `const sns = event.Records[0].Sns.Message;`

我想从 SNS JSON 变量中提取 Trigger.Namespace 和 Trigger.Dimensions.value 以及 Trigger.MetricName。

   const sns_NameSpace = sns.Trigger.Namespace;
   const sns_ApiId = sns.Trigger.Dimensions.value;
   const sns_MetricName = sns.Trigger.MetricName;
   console.log(sns_ApiId + '_' + sns_MetricName)
   console.log(sns_NameSpace)

我收到以下错误：

ERROR   Invoke Error    
{
    "errorType": "TypeError",
    "errorMessage": "Cannot read property 'Namespace' of undefined",
    "stack": [
        "TypeError: Cannot read property 'Namespace' of undefined",
        "    at Runtime.exports.handler (/var/task/index.js:7:38)",
        "    at Runtime.handleOnce (/var/runtime/Runtime.js:66:25)"
    ]

console.log(sns) returns the following:

{
    "AlarmName": "ZabbixPy 5XX Error - HTTP",
    "AlarmDescription": null,
    "AWSAccountId": "123456789",
    "NewStateValue": "ALARM",
    "NewStateReason": "Threshold Crossed: 1 out of the last 1 datapoints [24.0 (01/11/21 11:42:00)] was greater than or equal to the threshold (1.0) (minimum 1 datapoint for OK -> ALARM transition).",
    "StateChangeTime": "2021-11-01T11:43:35.422+0000",
    "Region": "Asia Pacific (Mumbai)",
    "AlarmArn": "arn:aws:cloudwatch:ap-south-1:1234567890:alarm:ZabbixPy 5XX Error - HTTP",
    "OldStateValue": "INSUFFICIENT_DATA",
    "Trigger": {
        "MetricName": "5xx",
        "Namespace": "AWS/ApiGateway",
        "StatisticType": "Statistic",
        "Statistic": "SUM",
        "Unit": null,
        "Dimensions": [
            {
                "value": "someid",
                "name": "ApiId"
            }
        ],
        "Period": 60,
        "EvaluationPeriods": 1,
        "ComparisonOperator": "GreaterThanOrEqualToThreshold",
        "Threshold": 1,
        "TreatMissingData": "- TreatMissingData:                    missing",
        "EvaluateLowSampleCountPercentile": ""
    }
}

Event data when trying to filter out:

Event data without any filters - console.log(sns):

Answer 1

使用您的 console.log(sns) 值进行测试时没有问题。

我能看到活动数据吗？

Answer 2

您应该将 JSON 解析为这样的对象：

const snsObj = JSON.parse(sns);

然后尝试访问属性:

snsObj.Trigger.Namespace

Nodejs 无法提取 JSON 值

Nodejs unable to extract JSON values

javascript

json

node.js

amazon-sns

aws-lambda