Receiving Inconsistent JSON Data - Class Object/Array of Class Objects

[RA-AlexRees]

Hi,
I have JSON data, from a client, where the input is either a class object or an array of class objects. Ideally, I would want to always have an array/list so if it is just a single class object, append it to the array instead.

I hope that makes sense.

[taowen]

 public static class MyList {
        public List<String> list;
    }

    public void test_list_or_single_element() {
        final TypeLiteral<List<String>> listOfString = new TypeLiteral<List<String>>() {
        };
        JsoniterSpi.registerTypeDecoder(MyList.class, new Decoder() {
            @Override
            public Object decode(JsonIterator iter) throws IOException {
                ValueType valueType = iter.whatIsNext();
                MyList myList = new MyList();
                switch (valueType) {
                    case ARRAY:
                        myList.list = iter.read(listOfString);
                        return myList;
                    case STRING:
                        myList.list = new ArrayList<String>();
                        myList.list.add(iter.readString());
                        return myList;
                    default:
                        throw new JsonException("unexpected input");
                }
            }
        });
        MyList list1 = JsonIterator.deserialize("\"hello\"", MyList.class);
        assertEquals("hello", list1.list.get(0));
        MyList list2 = JsonIterator.deserialize("[\"hello\",\"world\"]", MyList.class);
        assertEquals("hello", list2.list.get(0));
        assertEquals("world", list2.list.get(1));
    }

[jasonk000]

This corresponds to the Jackson features:

• DeserializationFeature.ACCEPT_SINGLE_VALUE_AS_ARRAY
• SerializationFeature.WRITE_SINGLE_ELEM_ARRAYS_UNWRAPPED.

(Noted here to help others searching for the issue).