public void testSort3(){
/**

• 创建10条随机字符串
• 字符串的长度在10以内
• 字符可随机生成，可重复

• 10条字符串不重复
  */
  List<String> stringList = new ArrayList<String>();

     String a = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
     Random random = new Random();           
     int count=0;
     while(count<10){
         StringBuilder stringbuilder = new StringBuilder();
         int rand = random.nextInt(10);
      for (int i = 0; i <= rand; i++) { 
  
          int rand1 = (int) (Math.random() * a.length()); 
          char c = a.charAt(rand1);
           stringbuilder = stringbuilder.append(c);
  
      }           
      if(!stringList.contains( stringbuilder)){
          stringList.add(stringbuilder.toString());
          count++;
           System.out.println("字符串:"+stringbuilder);
      }
      }
     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);               
     }

  }