如何通过mongodb Java driver 3.4+使用封顶集合添加多个文档？

Question

I want to add several document using capped collection and writing like:

// this code insert only first document using capped collection 
MongoDatabase database = mongoClient.getDatabase("db");
        database.createCollection("capped_collection",
                new CreateCollectionOptions().capped(true).sizeInBytes(536870912).maxDocuments(5000));

        MongoCollection<Document> collection = database.getCollection("capped_collection");

        Document found = database.getCollection("capped_collection").find(new Document("title", title)
                .append("url", url)
                .append("img", img)
                .append("price", price)).first();

        if (found == null) {

            collection.insertOne(new Document("title", title)
                            .append("url", url)
                            .append("img", img)
                            .append("price", price));

            mongoClient.close();
    }

In this case capped collection gives me to insert only first document and that's all (I want several not one). If I create normal collection I can insert several docs. Why it happens?

MongoDatabase database = mongoClient.getDatabase("db");
        MongoCollection<Document> collection = database.getCollection("normal_collection");

        Document found = database.getCollection("normal_collection").find(new Document("title", title)
                .append("url", url)
                .append("img", img)
                .append("price", price)).first();

        if (found == null) {
            collection.insertOne(new Document("title", title)
                            .append("url", url)
                            .append("img", img)
                            .append("price", price));

            mongoClient.close();
        }

In this way I can insert several documents using normal collection.

As I understand properly, there is no difference in the code between inserting documents into a capped collection and a normal collection, but in fact I have different results.

Updated: Just tried manually to add docs in capped collection via powershell

In powershell manually could be like:

Documents looks like (as test):

Correct me, please, if I'm wrong. Thanks for help.

Answer 1

Finally solve it. I needed to check for an existing collection :

boolean collectionExists = mongoClient.getDatabase("db_feed").listCollectionNames()
                .into(new ArrayList<>()).contains("capped_collection");

        if(!collectionExists) {
            database.createCollection("capped_collection",
                    new CreateCollectionOptions().capped(true).sizeInBytes(327).maxDocuments(1).autoIndex(true));
        }