Mongo Java: How to serialize DBObject as JSON on file?
===

I have a document in `MongoDB` as  

    name: name
    date_created: date
    p_vars: {
       01: {
          a: a,
          b: b,
       }
       02: {
          a: a,
          b: b,
       }
       ....
    }
represented as `DBObject`

- All `key`, `value` pairs are of type `String`  
- I want to serialize this document using Java, Looking at the [api][1], I did not find anything, How can I serialize a `DBObject` as `JSON` on file?

  [1]: http://api.mongodb.org/java/2.8.0/