Json is a way to structure data quickly and with good readability and has a key/data structure very similar to the java hasmap or the python dictionary.
the two ways to use JSON in TotalCross:
You need to create the data beans that will be received in JSON
//Where the data parameter is a variable that contains the JSONResponse response = JSONFactory.parse(data, Response.class);
You can see more abount this in REST API
//Where the data parameter is a variable that contains the JSONJSONObject jsonObject = new JSONObject(data);
You can use the variable jsonObject like a hashmap.
See a project on github using JSON