如何将名称/值对添加到JSONArray

Question

I'm sending a json object to a REST url as :

JSONObject loan=new JSONObject();
loan.put("clientId", "1");
loan.put("productId", "1");

Now I also have to send an array as part of the payload :

{  
    "clientId": 1,
    "productId": 1, 
    "disbursementData": [
        {
            "expectedDisbursementDate":"21 December 2018",
            "principal":2000,
            "approvedPrincipal":2000
        }
    ]    
}

How do I send the array disbursementData using the JSONObject as I'm doing with the other elements

I have tried using:

JSONArray arr = new JSONArray();
arr.put("expectedDisbursementDate","21 December 2018");
arr.put("principal", "1000");
arr.put("approvedPrincipal", "1000");
loan.put("disbursementData", arr);

I get the following exception :

The method put(int, boolean) in the type JSONArray is not applicable for the arguments (String, String).

It appears my issue is with adding a name-value pair to JSONArray. Any help on how I can achieve this?

Answer 1

Logic would be the same for any library but the syntax will differ. I am using the com.google.gson library.

Create object to be placed in the array :

JsonObject jsonObj = new JsonObject();
jsonObj.addProperty("expectedDisbursementDate", "21 December 2018");
jsonObj.addProperty("principal", "2000");
jsonObj.addProperty("approvedPrincipal", "2000");

Create the array and add the object to it :

JsonArray jsonArray = new JsonArray();
jsonArray.add(jsonObj);

Add the array to the original json object :

JsonObject loan = new JsonObject();
loan.addProperty("clientId", "1");
loan.addProperty("productId", "1");
loan.addProperty("disbursementData", jsonArray.toString());

Answer 2

You have to create a JSONObject, put it in a JSONArray and then add it to your first JSONObject, try the following code:

    JSONObject aux=new JSONObject();
    aux.put("expectedDisbursementDate","21 December 2018");
    aux.put("principal", "1000");
    aux.put("approvedPrincipal", "1000");
    JSONArray arr = new JSONArray();
    arr.put(aux);
    loan.put("disbursementData",arr);

Answer 3

JSONArray implements Collection (the json.org implementation from which this API is derived does not have JSONArray implement Collection). And JSONObject has an overloaded put() method which takes a Collection and wraps it in a JSONArray (thus causing the problem). I think you need to force the other JSONObject.put() method to be used:

you try to add below line

loan.put("disbursementData", (Object)arr);

You should file a bug with the vendor, pretty sure their JSONObject.put(String,Collection) method is broken.

Answer 4

You are creating JSONArray, array is not map and doesnt support put(key,value). You have to use put(int index, Object value), where index is the array index(same as array[index]). In your case the value should be the JSONObject :

 {
            "expectedDisbursementDate":"21 December 2018",
            "principal":2000,
            "approvedPrincipal":2000
        }