Convert array to comma-separated string, string to array

1. Convert array to comma separated string

List<String> list = new ArrayList<String>();
list.add("一屏");
list.add("二屏");
list.add("三屏");
  
String str = StringUtils.join(list, ",");

result

One screen, two screens, three screens

2. Convert string with comma to array

String str = "一屏,二屏,三屏";
List<String> result = Arrays.asList(str.split(","));

result

[One screen, two screens, three screens]