Java入门第三季 6-5 Collections实现随机字符串排序

/** * 1、创建完List<String>之后， 往其中添加十条随机字符串 *
 * 2每条字符串的长度为10以内的随机整数 
 *  3、每条字符串的每个字符都为随机生成的字符，字符可以重复 
 *   4、每条随机字符串不可重复
 *  */
public void testSort3(){
    List<String> stringlistList = new ArrayList<String>();
    Random random = new Random();
    for(int i = 0; i < 10; i++){
        StringBuilder tempString = new StringBuilder();
        int ran = random.nextInt(10);
        if(ran == 0){
            ran = 10;
        }
                for(int k = 0; k < ran; k++){

                    int type = random.nextInt(3);
                    if(type == 1){
                        tempString.append((char)('0' + random.nextInt(10)));
                    }
                    else if(type == 0) {
                        tempString.append((char)('a' + random.nextInt(26)));
                    }
                    else{
                        tempString.append((char)('a' + random.nextInt(26)));
                    }
                }
                if(i == 0)
                {
                    stringlistList.add(tempString.toString());
                }
                else if(stringlistList.contains(tempString.toString())){
                    i--;
                }
                else {
                    stringlistList.add(tempString.toString());
                }
    }

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