Java - Insert/Update with MongoDB collection bulkWrite

I am very new to MongoDB. Trying to understand the best option to perform Bulk Write in MongoDB. I want to periodically refresh my Application collection. The key's for documents are AppID, AppName and AppStatus. Below are the actions I want to perform in every run -

1. Find the AppID in Application collection.
2. If not exists, perform an insert
3. If exists, only update the value of AppStatus key.

List<Application> applist = getAppList(); // List contains All the Application

private final MongoClient mongoClient;

private final MongoTemplate mongoTemplate;

MongoCollection<Document> collection =
                  mongoTemplate.getDb().getCollection("Application");
collection.bulkWrite (????);

How do I loop over the appList and perform a bulk insert/update ?

You can use org.springframework.data.mongodb.core.BulkOperations to perform bulk update/insert/upsert/delete operations.

List<Application> applist = getAppList();

List<Pair<Query, Update>> updates = new ArrayList<>(applist.size());
applist.forEach(application -> {
    Query query = Query.query(Criteria.where("AppID").is(application.getAppID()));

    Update update = new Update();
    update.set("AppID", application.getAppID());
    update.set("AppName", application.getAppName());
    update.set("AppStatus", application.getAppStatus());

    updates.add(Pair.of(query, update));
});

BulkOperations bulkOperations = mongoTemplate.bulkOps(BulkOperations.BulkMode.UNORDERED, "Application");
bulkOperations.upsert(updates);
bulkOperations.execute();