教えていただいたSekigae.javaの改良版！

Sekigae_tnmt.java

import java.util.ArrayList;
import java.util.Collections;
import org.apache.commons.lang3.StringUtils;
import org.apache.commons.lang3.time.DateUtils;

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

  ArrayList<String> list = new ArrayList<String>();

        list.add("okkun");
        list.add("kitak");
        list.add("keoken");
        list.add("gussun");

        Collections.shuffle(list);
        String result = StringUtils.join(list.toArray(), ",");
        System.out.println(result);
        // System.out.println(StringUtils.join(list, " | "));

        // System.out.println(list.get(0) +" | "+ list.get(1) +" | "+
        //                 list.get(2) +" | "+ list.get(3));
    }
}