java逗号拼接字符串并且截断最后一个逗号

					List<String> strings = new ArrayList<>();
                    strings.add("aa");
                    strings.add("bb");
                    strings.add("cc");
                    StrBuilder strBuilder = new StrBuilder();
                    for (String s : strings) {
    
      
                        strBuilder.append((s)).append(",");
                    }
                    //转换string
                    String name = strBuilder.toString();
                     System.out.println(name);//a,b,c,
                    //截断最后一个字符
                    String substring = name.substring(0, name.length() - 1);
                    System.out.println(substring);//a,b,c