Programming Problem - AlphaNumericString ADT
You are to create an Abstract Data Type (ADT) called AlphaNumericString
that represents a string containing only alphanumeric characters (no
punctuation symbols).
Design and implement your ADT as a Java class named AlphaNumericString.
Your class must implement the following operations:
AlphaNumericString(String newstring) Constructor for objects
of this class.
getLength() Accessor to string's length. Return an
integer.
getLetterCount() Determine how many letters are in the
string. Return an integer.
getDigitCount() Determine how many numeric digits are in the
string. Return an integer.
getDigitSum() Compute the sum of all numeric digits in the
string. Return an integer.
isValid() Determine if the string contains only alphanumeric
characters. Return a boolean.
You should test your class using a separate driver or JUnit test.
Do not include a main method in the AlphaNumericString class.