Null Pointer Exception in Thread

Sathyaayyanar

Hai,

In LS sometimes it display the NullPointerException.


Exception in thread "Thread-168" java.lang.NullPointerException
        at com.chellasoft.activetrader.utils.OrderUtilities.run(OrderUtilities.j
ava:72)

The run function of Order Utilities as follows,


public void run() {
	//send order request/modify/cancel message 
	if (user != null) {
	try {
		OrderRequestMessage orderRequestMessage = new OrderRequestMessage();
		orderRequestMessage.setOrderValue(message);
		String jsonString = orderRequestMessage.toJSON();
		  	
                JsonSingleUserMessage jsonSingleUserMessage = new  JsonSingleUserMessage(user.getUserId(), jsonString.length(), jsonString, CustomConstants.JSONMessageTypes_OrderRequestMessage);  	  ProcessBrowserMessages.getInstance().sendJSONSingleUserMessage(jsonSingleUserMessage);
	}catch(JSONException e) {
	logger.severe("Error getting when parse order request message : " + e.getMessage() + "......");
			}
	
		} else {
			logger.info("Invalid user: " + user.getUserName() + " to place Order");
		}
		
		/*PrepareOrderArgs prepareOrderArgs = new PrepareOrderArgs(user, message);
		orderArgs = prepareOrderArgs.getOrderArgs();
		placeOrder();*/
	}

Please give suggestion for this issue.

Thanks in advance.

Mone

NullPointerException means that you tried to call a method or access a property on a variable that is actually null.

e.g.
if orderRequestMessage.toJSON(); returns null then the jsonString.length() on the following line will throw the NullPointerException.

moreover the exception tells you on which line it happened (in your case 72)

if the issue is reproducible at will you may debug your code step by step keeping an eye on the values of the variables

HTH