Java8中将list转换为用逗号隔开的字符串的几种方法

 public static <T> String parseListToStr(List<T> list){
       String result = Joiner.on(",").join(list);
        return result;
  }

public static <T> String parseListToStr2(List<T> list){
     StringBuffer sb = new StringBuffer();
     list.stream().forEach(str->{
         sb.append(str).append(",");
     });
     sb.deleteCharAt(sb.length()-1);
     return sb.toString();
}

 public static <T> String parseListToStr3(List<T> list){
      String result = list.stream().map(String::valueOf).collect(Collectors.joining(","));
      return result;
 }

public static <T> String parseListToStr(List<T> list){
        StringBuffer sb = new StringBuffer();
        if(listIsNotNull(list)) {
            for(int i=0;i<=list.size()-1;i++){
                if(i<list.size()-1){
                    sb.append(list.get(i) + ",");
                }else {
                    sb.append(list.get(i));
                }
            }
        }
        return sb.toString();
    }