Convert JSON to java objects with gson
Gson gson = new Gson();
// 1. JSON file to Java object
Staff staff = gson.fromJson(new FileReader("C:\\projects\\staff.json"), Staff.class);
// 2. JSON string to Java object
String json = "{'name' : 'mkyong'}";
Staff staff = gson.fromJson(json, Staff.class);
// 3. JSON file to JsonElement, later String
JsonElement json = gson.fromJson(new FileReader("C:\\projects\\staff.json"), JsonElement.class);
String result = gson.toJson(json);