import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

public class SortAlphabetically {
public static void main(String[] args) {
    Scanner scanner = new Scanner(System.in);
    List<Character> alpha = new ArrayList<Character>();

    System.out.println("Enter a word or phrase");
    StringBuilder input = new StringBuilder(scanner.next());
    scanner.close();

    for (int i = 0; i < input.length(); i++) {
        if (Character.isWhitespace(input.charAt(i))) {
            input.deleteCharAt(i);
        } else {
            alpha.add(input.charAt(i));
        }
    }

    alpha.sort(null);
    System.out.println("Input sorted alphabetically: " + alpha);
    }
}

Enter a word or phrase
cba fed
Input sorted alphabetically: [a, b, c]