Return JSON on output Swift

Question

My Swift code output this:

{
date = "2016-08-25 20:46:35 +0000";
observation = "";
products =     (
            {
        name = cafe;
        quantity = 1;
    },
            {
        name = cappuccino;
        quantity = 1;
    }
);
room = Platinium;
}

But I need this JSON

{
"date": "2016-08-25 20:46:35 +0000",
"observation": "",
"products": [{
    "name": "cafe",
    "quantity": 1
}, {
    "name": "cappuccino",
    "quantity": 1
}],
"room": "Platinium"
}

My classes is (Products and Order):

 class Products  { 
    var name: String = ""
    var quantity: Int = 0

    init(name: String, quantity: Int) {
      self.name = name
    self.quantity = quantity
    }
 }
 class Order{
   var room: String = ""
   var products: Array<Products> = []
   var observations: String = ""
   var date: NSDate! = nil
   init(room: String, products:Array<Products>, observations: String, date: NSDate){
       self.room = room
       self.products = products
       self.observations = observations
       self.date = date
    }
 }

And this Swift 2 code to transform in json.. After I'm using a try/catch to transform in json with NSJSONSerialization

let para:NSMutableDictionary = NSMutableDictionary()
let prodArray:NSMutableArray = NSMutableArray()


            para.setValue(String(receivedString), forKey: "room")
            para.setValue(observationString, forKey: "observation")
            para.setValue(stringDate, forKey: "date")

            for product in products{
                let prod: NSMutableDictionary = NSMutableDictionary()
                prod.setValue(product.name, forKey: "name")
                prod.setValue(product.quantity, forKey: "quantity")
                prodArray.addObject(prod)
            }
            para.setObject(prodArray, forKey: "products")

Someone help me? Thank you very much!!