Question

I have Json string, which contain “key” : “value” pairs and i need to know keys at this string using Java and importing org.json. I tried to use iterator, but first pair key prints in the end.

for example string:

{
   "firstName": "sam",
   "lastName": "Smith",
   "address": {
       "streetAddress": "somestreet",
       "city": "somecity",
       "postalCode": 101101
   },
   "phoneNumbers": [
       "812 123-1234",
       "916 123-4567"
   ]
}

I want to print:
”
firstName
lastName
address
phoneNumbers
“.
But i have:
“lastName
address
phoneNumbers
firstName”

 JSONObject JO = new JSONObject(JsonString);
    Iterator<String> It = JO.keys();

       while (It.hasNext()){        
       System.out.println(It.next());
       }

Answer 1

From the JavaDoc:

A JSONObject is an unordered collection of name/value pairs.

If you want to order the keys you must 1) place them in a list and 2) order the list according your needs. Keep in mind that this is a key/value representation of data – the sequence of elements should not matter.