1. 逗号分隔的字符串转 List
(1)转 List<String>
String str = "1,2,3,4,5,6";
List<String> list = Arrays.stream(str.split(","))
.map(String::trim).collect(Collectors.toList());
(2)转 List<Long>
String str = "1,2,3,4,5,6";
List<Long> list = Arrays.stream(str.split(","))
.map(s -> Long.parseLong