thread “main” java.lang.NumberFormatException: null

Question

I\'m a beginner to Java programming and I encounter the following exception:

Exception in thread \"main\" java.lang.NumberFormatException: null
            at ja         


        

Answer 1

That exception means that when you are executing this line of code

id1 = Integer.valueOf(id).intValue();

the value you are trying to convert into an integer (id), isn't a number.

You need to double check your input file's format.