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:

Answer 1

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