How can I manage a json of this way?

[cristianhoyos66-zz]

We guess that i'm expecting a json of this way: {info: {coordinates: [12345, -12345], name: 'coordinateName'}} how can I manage that in onDataAdded method?

I'm testing this way to get coordinates:

Database database = mMeteor.getDatabase();
 public void onDataAdded(String collectionName, String documentID, String newValuesJson) {
    JSONObject infoField =  (JSONObject) database.getCollection(collectionName).getDocument(documentId).getField("info");
    JSONArray coor = infoField.getJSONArray("coordinates"); 
   }

How can i manage that? or is this a right way?

thank you.

[ocram]

Thanks for your question!

It seems you had the correct idea already. This is how you query the database, in case you have activated it as described in the README:

database.getCollection(collectionName);
database.getCollection(collectionName).getDocument(documentId);
database.getCollection(collectionName).getDocument(documentId).getField("info");

No need to convert to JSONObject!

You can also check what is in there by printing the contents to your console as follows:

System.out.println(database.getCollection(collectionName));
System.out.println(database.getCollection(collectionName).getDocument(documentId));
System.out.println(database.getCollection(collectionName).getDocument(documentId).getField("info"));

Does that help?

[cristianhoyos66-zz]

Yes, I understand that, thank you, but to get coordinates How can I do that?

I tried this: database.getCollection(collectionName).getDocument(documentId).getField("coordinates"); and it returns null so I think that I need to get first info field to can get coordinates field, but if I do this:

Object infoField = database.getCollection(collectionName).getDocument(documentId).getField("info");

I can't get coordinates from infoField so I don't know how could I get coordinates field.

Thanks for answering.

[ocram]

Getting the info field first and then retrieving the coordinates from there is correct, of course. Because this is how you structured your records. You cannot get the coordinates without getting the info first.

What's the value of the info object?

database.getCollection(collectionName).getDocument(documentId).getField("info")

Did you print this to the console, as suggested?

System.out.println(database.getCollection(collectionName).getDocument(documentId).getField("info"));

[cristianhoyos66-zz]

Yes, I printed that, and it shown this: {coordinates: [12345, -12345], name: 'coordinateName'}

[ocram]

That's great! The line that was printed was what we expected, right?

As a next step, can you please check what's the type of infoField? (That's what you printed, isn't it?) That would allow us to extract the single coordinates from the object. It should be an instance of Map<String, Object>, probably of Fields. So let's see what we need:

// check the class of the `infoField` object and print it
System.out.println(infoField.getClass().getName());
// try to convert the object to a map (`{}` when printed) so that we can access the properties
Map<String, Object> infoMap = (Map<String, Object>) infoField;
// try to access the `coordinates` property
Object coordinatesField = infoMap.get("coordinates");

// check the class of the `coordinatesField` object and print it
System.out.println(coordinatesField.getClass().getName());
// try to convert the object to a list (`[]` when printed) so that we can access the elements
List<Object> coordinatesArray = (List<Object>) coordinatesField;

// the single coordinates are now, hopefully, the first two elements
System.out.println(coordinatesArray.get(0)+" and "+coordinatesArray.get(1));

Does that work? What's printed to the console?

[ocram]

Closing due to inactivity

[cristianhoyos66-zz]

Yes, I forgot to close this issue. Thank you anyway, you solved my doubts

[ocram]

No problem :) Thanks!