string转List

String str = "1,2,3,4,56";
//string 转list
List<String> list = Arrays.asList(str.split(","));
log.info("list:{}", list);
//print:[1, 2, 3, 4, 56]
list.forEach(log::info);

List转String

方式一

String collect = list.stream().collect(Collectors.joining(","));
log.info("collect:{}", collect);

方式二

String collect = String.join(",", list);
log.info("collect:{}", collect);