MongoDB queries using Java

[Gareth Edwards]

I am working on a project that uses a mongoDB database to store and extract data from. I currently have a situation where I want to query all documents (with specific conditions) in a collection and return the value of a single field. 

For example: There is a field called "marks" in each document and I want to return the value in  "marks". So if the "marks" field has the value of 5 in each of the 3 documents I want to obtain [5,5,5] (i.e 5 three times). So the distinct method doesn't work and so far that's the only method I've been finding on the internet so far.

Any help will be much appreciated.

Thanks

[Chris Carman]

What's wrong with this example from the docs
(https://mongodb.github.io/mongo-java-driver/3.4/driver/getting-started/quick-start/)
?
Seems pretty straightforward.

Block<Document> printBlock = new Block<Document>() {
@Override
public void apply(final Document document) {
System.out.println(document.toJson());
}
};

collection.find(gt("i", 50)).forEach(printBlock);