NumberFormatException: Invalid int even if it is really an integer

Question

I encounter some problems parsing a string into integer, I don't know what the problem is.

I am passing a string with an integer value to my function to check if it would be parseable.

This is my function.

private boolean isNumeric (String value){
        try {
            System.out.println("VALUE = " +value);
            int x = Integer.parseInt(value);
            return true;
        } catch (NumberFormatException e) {
            System.out.println("NumberFormatException: " + e.getMessage());
            return false;
        }
    }

I checked it by printing into the console. here is the result.

I/System.out: VALUE = 77
    NumberFormatException: Invalid int: "77"

Can you guys help me figure out what is wrong here. Cause I cannot convert this string into an integer.

Answer 1

You could try this as this will trim out all whitespaces from your input:

private boolean isNumeric (String value){
        try {
            System.out.println("VALUE = " +value);
            int x = Integer.parseInt(value.trim());
            return true;
        } catch (NumberFormatException e) {
            System.out.println("NumberFormatException: " + e.getMessage());
            return false;
        }
    }

parseInt() should return a NumberFormatException if the string is not parseable, but "77" should be. You should therefore try to trim it before you parse it to an int, maybe that would help.