How to find the Sum of Digits in an Alphanumeric value ?

package pack1;

public interface AlphanumericIntf {

	/* Define the functional interface with SAM 'ParseAlphanumeric' */
	float ParseAlphanumeric(String str1);

	/* Define the static method 'displayMsg' */
	static void displayMsg(String inpSen, float sumVal) {
		
		System.out.println("The sum of digits in the given string '" + inpSen + "' is " + sumVal);
		System.out.println("\n");
	}
}

package pack1;

import java.util.ArrayList;
import java.util.Optional;
import java.util.logging.Logger;

class InputAlphanumeric {

	private String strParam;
	float sumDigits = 0;
    
	/* Declare the logger object for the class to display the log messages */
	static Logger logger = Logger.getLogger(InputAlphanumeric.class.getName());

	public boolean validateInputs(String alphaNumericValue) {

		/* Fetch the class object's name from which this method is called */
		String cName = Thread.currentThread().getStackTrace()[2].getClassName();
		String mName = "validateInputs()";
		logger.info("This method '" + mName + "' called from the Class '" + cName + "'");

		/* Validating the function parameters using Optional String data type methods */
		Optional<String> strInput = Optional.ofNullable(alphaNumericValue);

		/*
		 * Fetch the value of the Optional String parameters using 'isPresent' condition
		 * check. If the value is available use 'get' method otherwise simply return
		 * 'false' to stop the program execution without proceeding further.
		 */
		if (strInput.isPresent()) {
			setStrParam(strInput.get());
		} else {
			return false;
		}

		logger.info("The provided Input validated Successfully");
		return true;
	}

	/* Define getter and setters for strParam & sumDigits variables */
	public String getStrParam() {
		return strParam;
	}

	public void setStrParam(String strings) {
		this.strParam = strings;
	}
	
	public float getSumDigits() {
		return sumDigits;
	}

	public void setSumDigits(float sumDigits) {
		this.sumDigits = sumDigits;
	}
}

class SumDgtsInAlphanumeric_Using_String extends InputAlphanumeric implements AlphanumericIntf {

	public float ParseAlphanumeric(String alphaNumericStr) {

		/* Fetch the class object's name from which this method is called */
		String cName = Thread.currentThread().getStackTrace()[2].getClassName();
		String mName = "ParseAlphanumeric";
		logger.info("This method '" + mName + "' called from the Class '" + cName + "'");

		if (validateInputs(alphaNumericStr)) {

			System.out.println("The given input alphaNumeric value is = '" + alphaNumericStr + "'");
			/*
			 * Traversing through each character of the alphanumeric input, and check whether
			 * any character is digit. If digit found, sum of all digits.
			 */
		   int lenOfStr=alphaNumericStr.length();
	        while (lenOfStr > 0) {
	        	if (Character.isDigit(alphaNumericStr.charAt(lenOfStr-1)))
	        	setSumDigits(getSumDigits()+Character.getNumericValue(alphaNumericStr.charAt(lenOfStr-1)));
	            lenOfStr=lenOfStr-1;
	        }

		} else
			logger.info("The given Input Alphanumeric is null");
		
        AlphanumericIntf.displayMsg(alphaNumericStr,getSumDigits());
		return getSumDigits();
	}
}

class SumDgtsInAlphanumeric_Using_Lamdba extends InputAlphanumeric implements AlphanumericIntf {

	public float ParseAlphanumeric(String alphaNumericStr) {

		/* Fetch the class object's name from which this method is called */
		String cName = Thread.currentThread().getStackTrace()[2].getClassName();
		String mName = "ParseAlphanumeric";
		logger.info("This method '" + mName + "' called from the Class '" + cName + "'");
		
		/* Define the Lambda expression for the user defined functional interface */
		/*
		 * Traversing through each character of the alphanumeric input, and check whether
		 * any character is digit. If digit found, sum of all digits.
		 */
		AlphanumericIntf ds = ((alphaNumStr) -> {
            int lenOfStr = alphaNumStr.length(), sum = 0;
            while (--lenOfStr >= 0)
                if (Character.isDigit(alphaNumStr.charAt(lenOfStr)))
                    sum += Character.getNumericValue(alphaNumStr.charAt(lenOfStr));
            return sum;
        });

		if (validateInputs(alphaNumericStr)) {

			System.out.println("The given input sentence is = '" + alphaNumericStr + "'");
			setSumDigits(ds.ParseAlphanumeric(alphaNumericStr));
			
		} else
			logger.info("The given Input Alphanumeric is null");
		
	    AlphanumericIntf.displayMsg(alphaNumericStr,getSumDigits());
		return getSumDigits();
	}
}

class SumDgtsInAlphanumeric_Using_Stream extends InputAlphanumeric implements AlphanumericIntf {

	public float ParseAlphanumeric(String alphaNumericStr) {

		/* Fetch the class object's name from which this method is called */
		String cName = Thread.currentThread().getStackTrace()[2].getClassName();
		String mName = "ParseAlphanumeric";
		logger.info("This method '" + mName + "' called from the Class '" + cName + "'");

		if (validateInputs(alphaNumericStr)) {

			System.out.println("The given Alphanumeric is = '" + alphaNumericStr + "'");
			ArrayList<Character> arrChars = new ArrayList<Character>();
		        for (char ch : alphaNumericStr.toCharArray())
		            arrChars.add(ch);
		        System.out.println("The list of Characters are= " + arrChars);
		 
		        /* Apply filter, map methods on the extracted List of characters. 
		         * If the digits found, accumulate sum of digits in the reduce method 
		         */
		        setSumDigits(arrChars.stream().filter(c -> Character.isDigit(c))
		        								.map(x -> Character.getNumericValue(x))
		        								  .reduce(0, (a, b) -> a + b));
		} else
			logger.info("The given Input Alphanumeric is null");

		AlphanumericIntf.displayMsg(alphaNumericStr,getSumDigits());
		return getSumDigits();
	}
}


public class SumofDgtsInAlphanumericJ8 {
	
	public static void main(String[] args) {

		/*
		 * create the class object SumDgtsInAlphanumeric_Using_String, and call the method
		 * ParseAlphanumeric
		 */
		SumDgtsInAlphanumeric_Using_String SDUStr = new SumDgtsInAlphanumeric_Using_String();
		SDUStr.ParseAlphanumeric("Java25Python35Yaers");

		/*
		 * create the class object SumDgtsInAlphanumeric_Using_Lamdba, and call the method
		 * ParseAlphanumeric
		 */
		SumDgtsInAlphanumeric_Using_Lamdba SDULambda = new SumDgtsInAlphanumeric_Using_Lamdba();
		SDULambda.ParseAlphanumeric("Tomcat35Jboss20Weblogic15Years");

		/*
		 * create the class object SumDgtsInAlphanumeric_Using_Stream, and call the method
		 * ParseAlphanumeric
		 */
		SumDgtsInAlphanumeric_Using_Stream SDUStream = new SumDgtsInAlphanumeric_Using_Stream();
		SDUStream.ParseAlphanumeric("");
		
		SDUStream.ParseAlphanumeric(null);
	}
}