How to do concatenation of string in UDF

I have following udf code.

String MessageID;

java.util.Map param = container.getTransformationParameters();

MessageID = (String) param.get (StreamTransformationConstants.MESSAGE_ID);

return MessageID;

In above mentioned code string variable MessageID having value 500 and returning value, after execution of

this code. But requirement is value will return like (500) instead of 500. How to concatenate "(" and ")"  with string MessageID.

So value will come like - (500).

Thanks

Mrityunjoy