public synchronized void fromJson()

in iothub/device/iot-device-client/src/main/java/com/microsoft/azure/sdk/iot/device/twin/MethodParser.java [144:265]
79 lines of code
15 McCabe index (conditional complexity)

    public synchronized void fromJson(String json) throws IllegalArgumentException
    {

        if (json == null || json.isEmpty())
        {
            throw new IllegalArgumentException("Invalid json.");
        }

        JsonParser jsonParser = new JsonParser();
        try
        {
            JsonElement jsonElement = jsonParser.parse(json);
            if (jsonElement instanceof JsonPrimitive || jsonElement instanceof JsonArray)
            {
                /*
                   Basic JSON String or Array
                   Ex:
                       "this is payload."
                       1
                       true
                       2.0e10
                       2.6
                 */
                this.operation = Operation.payload;
                this.payload = jsonElement;
            }
            else if (jsonElement instanceof JsonObject)
            {
                JsonObject jsonObject = (JsonObject) jsonElement;
                JsonElement statusTagNode = jsonObject.get(STATUS_TAG);
                JsonElement methodNameNode = jsonObject.get(METHOD_NAME_TAG);
                if (methodNameNode == null)
                {
                    if (statusTagNode == null)
                    {
                        /*
                           If the json contains any payload without `methodName` or `status` identification, the fromJson shall parse only the payload, and set the operation as `payload`.
                           Ex:
                           {
                               "input1": "someInput",
                               "input2": "anotherInput"
                           }
                         */
                        operation = Operation.payload;
                        payload = jsonObject;
                    }
                    else
                    {
                        /*
                           If the json contains the `status` identification, the fromJson shall parse both status and payload, and set the operation as `response`.
                           Ex:
                           {
                               "status": 201,
                               "payload": {"AnyValidPayload" : "" }
                           }
                         */
                        operation = Operation.response;
                        if (statusTagNode.isJsonPrimitive())
                        {
                            status = statusTagNode.getAsInt();
                        }
                        JsonElement payloadNode = jsonObject.get(PAYLOAD_TAG);
                        if (payloadNode != null)
                        {
                            payload = payloadNode;
                        }
                    }
                }
                else
                {
                    if (statusTagNode == null)
                    {
                        /*
                           If the json contains the `methodName` identification, the fromJson shall parse the full method, and set the operation as `invoke`.
                           Ex:
                           {
                               "methodName": "reboot",
                               "responseTimeoutInSeconds": 200,
                               "connectTimeoutInSeconds": 5,
                               "payload":
                               {
                                   "input1": "someInput",
                                   "input2": "anotherInput"
                               }
                           }
                         */
                        operation = Operation.invoke;
                        name = methodNameNode.getAsString();
                        JsonElement responseTimeoutNode = jsonObject.get(RESPONSE_TIMEOUT_IN_SECONDS_TAG);
                        if (responseTimeoutNode != null)
                        {
                            responseTimeout = responseTimeoutNode.getAsLong();

                        }
                        JsonElement connetionTimeoutNode = jsonObject.get(CONNECT_TIMEOUT_IN_SECONDS_TAG);
                        if (connetionTimeoutNode != null)
                        {
                            connectTimeout = connetionTimeoutNode.getAsLong();
                        }
                        JsonElement payloadNode = jsonObject.get(PAYLOAD_TAG);
                        if (payloadNode != null)
                        {
                            payload = payloadNode;
                        }
                    }
                    else
                    {
                        throw new IllegalArgumentException("Invoke method name and Status reported in the same json");
                    }
                }
            }
            else
            {
                // JSON null, since string is not empty, it shouldn't reach here
                throw new IllegalArgumentException("Invalid json.");
            }
        }
        catch (Exception ex)
        {
            throw new IllegalArgumentException("Malformed json.", ex);
        }
    }