Query documents, update it and return it back to MongoDB

In my MongoDB 3.2 based application I want to perform the documents processing. In order to avoid the repeated processing on the same document I want to update its flag and update this document in the database.

The possible approach is:

Query the data: FindIterable<Document> documents = db.collection.find(query); .

Perform some business logic on these documents.

Iterate over the documents , update each document and store it in a new collection.

Push the new collection to the database with db.collection.updateMany(); .

Theoretically, this approach should work but I'm not sure that it is the optimal scenario.

My question:
Is there any way in MongoDB Java API to perform the followings two operations:

to query documents (to get them from the DB and to pass to the separate method);

to update them and then store the updated version in DB;

in more elegant way comparing to the proposed above approach?

---

You can update document inplace using update:

db.collection.update(
    {query},
    {update},
    {multi:true}
);

It will iterate over all documents in the collection which match the query and updated fields specified in the update .

EDIT:

To apply some business logic to individual documents you can iterate over matching documents as following:

db.collection.find({query}).forEach(
    function (doc) {
        // your logic business
        if (doc.question == "Great Question of Life") {
            doc.answer = 42;
        }
        db.collection.save(doc);
    }
)

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