List转变为逗号分隔的字符串

List转变为逗号分隔的字符串

List<String> list = new ArrayList<>();
        list.add("123");
        list.add("456");
        list.add("789");
        System.out.println(String.join(",",list));

String字符串分割

String string = "123,456,789";
string.split(",");//