Creating BSON object from JSON string

Question

I have Java app that takes data from external app. Incoming JSONs are in Strings. I would like to parse that Strings and create BSON objects.

Unfortunate I can\'t fi

Answer 1

Use Document.parse(String json) from org.bson.Document. It returns Document object which is type of Bson.

Answer 2

Official MongoDB Java Driver comes with utility methods for parsing JSON to BSON and serializing BSON to JSON.

import com.mongodb.DBObject;
import com.mongodb.util.JSON;

DBObject dbObj = ... ;
String json = JSON.serialize( dbObj );
DBObject bson = ( DBObject ) JSON.parse( json );

The driver can be found here: https://mongodb.github.io/mongo-java-driver/

Answer 3

... And, since 3.0.0, you can:

import org.bson.Document;

final Document doc = new Document("myKey", "myValue");
final String jsonString = doc.toJson();
final Document doc = Document.parse(jsonString);

Official docs:

• Document.parse(String)
• Document.toJson()

Answer 4

I am not sure about java but the mongoDB CPP driver has a function type

BSONObj fromjson(string)

which returns a BSONObj according to the string passed. There should be a same function in Java too.

Answer 5

The easiest way seems to be to use a JSON library to parse the JSON strings into a Map and then use the putAll method to put those values into a BSONObject.

This answer shows how to use Jackson to parse a JSON string into a Map.

Answer 6

You'll find the answer to your question in the source code of https://github.com/mongodb/mongo/blob/master/src/mongo/db/jsobj.cpp Which has the BSON to JSON conversion.

Basically, stuff like

• ObjectId("XXX") -> { "$oid" : "XXX" }
• /XXX/gi -> { "$regex" : "XXX", "$options" : "gi" }

and so on...