字符串轉數組，補全4位，再轉字符串

/*補全code*/
if(q.getCode()!=null){
    String[] codeArr = q.getCode().split(",");
    StringBuffer sb = new StringBuffer();
    for(int i=0;i<codeArr.length;i++){
        String cod = String.format("%04d",Integer.parseInt(codeArr[i]));
        sb.append(cod+",");
    }
    q.setCode(sb.deleteCharAt(sb.length()-1).toString());
}