Java comparable 和 comparator

public class ComparatorTest {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // ----写程序
        List<Step> list=new ArrayList<Step>();
        for (int i = 10; i < 12; i++) {
            list.add(new Step(i));
        }
        for (int i = 5; i < 9; i++) {
            list.add(new Step(i));
        }
        Comparators com=new Comparators();
        Collections.sort(list,com);
        System.out.println(list);
    }

}

class Step{
    int datatime;

    Step(int i){
        datatime=i;
    }
    public int getDatatime() {
        return datatime;
    }
    @Override
    public String toString() {
        // TODO Auto-generated method stub
        return "Step("+datatime+")";
    }
}

class Comparators implements Comparator<Step>{

    public int compare(Step o1, Step o2) {
        // TODO Auto-generated method stub
        
        return o1.getDatatime()>o2.getDatatime()?1:o1.getDatatime()==o2.getDatatime()?0:-1;
    }
    
}