Java中将List转化为以,分割的字符串或相反

• 将逗号分隔的字符串转换为List

List<String> list = Arrays.asList(str.split(","));
List<String> list = Arrays.asList(StringUtils.split(str, ","));

• 将list转化为逗号分割的字符串

String str = String.join(",", list);
String str = StringUtils.json(list.toArray(), ",");