StackOverflow - Q13348701

package stackoverflow;

import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

/**
 * @author TheLima
 */
public class Q_13348701 {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        String[] tests = {
            "11,22,33", //valid.
            "11,22,11", //not valid.
            "Nice,Code,Brian", //Flexible version of @Brian's - valid.
            "No,Means,No" //Flexible version of @Brian's - not valid.
        };

        System.out.println("My own initial method:");
        for (String s : tests) {
            System.out.println(isValid(s));
        }
        System.out.println();
        System.out.println("Modified Brian's \"Set method\":");
        for (String s : tests) {
            System.out.println(isValid_SetMethod(s));
        }
    }

    public static boolean isValid(String source) {
        List<String> list = new ArrayList<String>();
        for (String sub : source.split(",")) {
            if (list.contains(sub)) {
                return false;
            } else {
                list.add(sub);
            }
        }
        return true;
    }

    public static boolean isValid_SetMethod(String source) {
        Set<String> set = new HashSet<String>();
        for (String sub : source.split(",")) {
            if (!set.add(sub)) {
                return false;
            }
        }
        return true;
    }
}