JSON order mixed up

Question

I've a problem trying to make my page printing out the JSONObject in the order i want. In my code, I entered this:

JSONObject myObject = new JSONObject(); myObject.put("userid", "User 1"); myObject.put("amount", "24.23"); myObject.put("success", "NO"); 

However, when I see the display on my page, it gives:

JSON formatted string: [{"success":"NO", "userid":"User 1", "bid":24.23}]

I need it in the order of userid, amount, then success. Already tried re-ordering in the code, but to no avail. I've also tried .append....need some help here thanks!!

Answer 1

You cannot and should not rely on the ordering of elements within a JSON object.

From the JSON specification at https://www.json.org/

An object is an unordered set of name/value pairs

As a consequence, JSON libraries are free to rearrange the order of the elements as they see fit. This is not a bug.

Answer 2

I agree with the other answers. You cannot rely on the ordering of JSON elements.

However if we need to have an ordered JSON, one solution might be to prepare a LinkedHashMap object with elements and convert it to JSONObject.

@Test def void testOrdered() {     Map obj = new LinkedHashMap()     obj.put("a", "foo1")     obj.put("b", new Integer(100))     obj.put("c", new Double(1000.21))     obj.put("d", new Boolean(true))     obj.put("e", "foo2")     obj.put("f", "foo3")     obj.put("g", "foo4")     obj.put("h", "foo5")     obj.put("x", null)      JSONObject json = (JSONObject) obj     logger.info("Ordered Json : %s", json.toString())      String expectedJsonString = """{"a":"foo1","b":100,"c":1000.21,"d":true,"e":"foo2","f":"foo3","g":"foo4","h":"foo5"}"""     assertEquals(expectedJsonString, json.toString())     JSONAssert.assertEquals(JSONSerializer.toJSON(expectedJsonString), json) } 

Normally the order is not preserved as below.

@Test def void testUnordered() {     Map obj = new HashMap()     obj.put("a", "foo1")     obj.put("b", new Integer(100))     obj.put("c", new Double(1000.21))     obj.put("d", new Boolean(true))     obj.put("e", "foo2")     obj.put("f", "foo3")     obj.put("g", "foo4")     obj.put("h", "foo5")     obj.put("x", null)      JSONObject json = (JSONObject) obj     logger.info("Unordered Json : %s", json.toString(3, 3))      String unexpectedJsonString = """{"a":"foo1","b":100,"c":1000.21,"d":true,"e":"foo2","f":"foo3","g":"foo4","h":"foo5"}"""      // string representation of json objects are different     assertFalse(unexpectedJsonString.equals(json.toString()))     // json objects are equal     JSONAssert.assertEquals(JSONSerializer.toJSON(unexpectedJsonString), json) } 

You may check my post too: http://www.flyingtomoon.com/2011/04/preserving-order-in-json.html