在 AWS SNS 过滤中,未知消息属性不会被忽略,这意味着您需要为所有想要匹配的属性都创建一个过滤策略。要解决这个问题,您可以通过在过滤筛选器中添加适配器来忽略未知属性。以下是一个示例代码,用于在 Node.js 和 Typescript 中过滤 SNS 消息:
import * as AWS from 'aws-sdk';
import * as SNS from "aws-sdk/clients/sns";
AWS.config.update({ region: 'us-east-1' });
const sns: SNS = new AWS.SNS({ apiVersion: '2010-03-31' });
const subscriptions: any[] = [];
function subscribeToTopic(topicArn: string, filterPolicy: object) {
const params = {
Protocol: 'https',
TopicArn: topicArn,
Attributes: {
'FilterPolicy': JSON.stringify(filterPolicy)
}
};
sns.subscribe(params, function (err, data) {
if (err) {
console.error(err);
} else {
subscriptions.push(data.SubscriptionArn);
console.log('Subscribed to SNS topic successfully. Subscription ARN: ' + data.SubscriptionArn);
}
});
}
function handleSNSMessage(event: any) {
const snsMessage = event.Records[0].Sns;
console.log('Received SNS message: ' + JSON.stringify(snsMessage.Message));
// Check for known message attributes
if (snsMessage.MessageAttributes['attribute1']) {
// Process the message
}
if (snsMessage.MessageAttributes['attribute2']) {
// Process the message
}
}
// Subscribe to the SNS Topic
const topicArn = 'arn:aws:sns:us-east-1:123456789:mytopic';
const filterPolicy = {
"attribute1": ["value1", "value2"],
"attribute2": "value3"
};
subscribeToTopic(topicArn, filterPolicy);
// Listen to the SNS notifications
export const snsNotificationHandler = async (event: any) => {
console.log('Received SNS notification.');
await handleSNSMessage(event);
};
在此示例代码中,我们首先定义了 subscribeToTopic() 函数,该函数将在 SNS Topic 上创建一个订阅并添加筛选策略。然后,我们使用 handleSNSMessage() 函数来处理接收到的消息,该函数检查 MessageAttributes 是否有已知