因此，我在Sping Boot 应用程序中构建了一个非常基本的MongoDB更改流：

public class MongoDBChangeStream {

    public void changeStream() {

        // connect to the local database server
        MongoClient mongoClient = MongoClients.create("db uri goes here");

        // Select the MongoDB database
        MongoDatabase database = mongoClient.getDatabase("MyDatabase");

        // Select the collection to query
        MongoCollection<Document> collection = database.getCollection("teams");

        // Create pipeline for operationType filter
        List<Bson> pipeline = Arrays.asList(
                Aggregates.match(
                        Filters.in(
                                "operationType",
                                Arrays.asList("insert", "update", "delete")
                        )));

        // Create the Change Stream
        ChangeStreamIterable<Document> changeStream = collection.watch(pipeline)
                .fullDocument(FullDocument.UPDATE_LOOKUP);

        // Iterate over the Change Stream
        for (ChangeStreamDocument<Document> changeEvent : changeStream) {
            // Process the change event here
            switch (changeEvent.getOperationType()) {
                case INSERT:
                    System.out.println("MongoDB Change Stream detected an insert");
                    break;
                case UPDATE:
                    System.out.println("MongoDB Change Stream detected an update");
                    break;
                case DELETE:
                    System.out.println("MongoDB Change Stream detected a delete");
                    break;
            }
        }
    }
}

正如您所看到的，我正在监听***'teams'集合中的***insert、updates***和***deletes，然后在控制台中打印出相应的消息。
但是实际上我如何启动侦听器呢？当我运行应用程序时，需要启动changeStream，以便它开始监视集合..我如何做到这一点呢？