//集合--字符串--转换
List<Long> fileIds = Lists.newArrayList();
//list转成用逗号隔开的字符串
String fileids = StringUtils.join(fileIds.toArray(), ",");
//按照逗号分割转成list
List<String> fileIds= Arrays.asList(fileids.split(","));
//集合--字符串--转换
List<Long> fileIds = Lists.newArrayList();
//list转成用逗号隔开的字符串
String fileids = StringUtils.join(fileIds.toArray(), ",");
//按照逗号分割转成list
List<String> fileIds= Arrays.asList(fileids.split(","));