public void testSort2() {
        List<String> stringlist=new ArrayList<String >();
        String a="dsadwqfsbcvigntlerimcjzfoweqjoeqwjoifiowqeog2128";
      Random random=new Random();
      for(int i=0;i<10;i++) {
      String st=new String();

          do {
        for(int j=0;j<random.nextInt(10)+1;j++) {     
           int number=random.nextInt(a.length());
           st=st+a.charAt(number);
        }
          }while(stringlist.contains(st));
              stringlist.add(st);
          }

        System.out.println("------排序前------");
        for(String string:stringlist) {
            System.out.println("元素:"+string);
        }
        Collections.sort(stringlist);
        System.out.println("------排序后------");
        for(String string:stringlist) {
            System.out.println("元素:"+string);
        }

    }