我如何从同一方法返回2 ArrayList

Question

我有一个方法如下,这个方法包含两个arraylist("eventList"和"emailList").

List<EmailUID> emailid=SharedEvent.getEmailUid(filter, uri, exchWD, EmailShare);

public static List<EmailUID> getEmailUid(Filter filter, String uri, NexWebDav exchWD,
            List<String> emailShare)
List eventsToday = null;
List<EmailUID> arrayList = new ArrayList<EmailUID>();
List<EmailUID> emailList = new ArrayList<EmailUID>();
List<EmailUID> eventList = new ArrayList<EmailUID>();

        for (String email : emailShare) {
            String uris = uri + email + "/events/";
            InputStream stream = null;
            try {
                stream = exchWD.get(uris);
                BufferedReader br = new BufferedReader(new InputStreamReader(stream));
                CalendarBuilder builder = new CalendarBuilder();
                net.fortuna.ical4j.model.Calendar calendar = builder.build(br);

                //eventsToday.add(email);

                eventsToday = (List<?>) filter.filter(calendar.getComponents(Component.VEVENT));
                arrayList=getEmailUID(eventsToday,email);
                emailList.addAll(arrayList);//
                eventList.addAll(eventsToday);//

            } catch (ParserException e) {
                LOGGER.error("Parse Exception"+e.getMessage());
            } finally {
                IOUtils.closeQuietly(stream);
            }
        }
    //return eventList;
    return emailList;
    }

如何同时获取列表"eventList"和"emailList"

Answer 1

它不是可能的两return statement从单一的功能,但你可以在新的包装Map或者List,可以返回两个ArrayList中.

public Map<String,List<EmailUID>> getList()
  List<EmailUID> emailList = new ArrayList<EmailUID>();
  List<EmailUID> eventList = new ArrayList<EmailUID>();
  ...
  Map<String,List<EmailUID>> map =new HashMap();
  map.put("emailList",emailList);
  map.put("eventList",eventList);
  return map;
}

Answer 2

好吧,如果你真的需要,你可以将它们包装成一个对象,它只有2个List字段.

另外,您可以返回2个列表的地图,每个列表都有一个唯一的键.

Answer 3

您可以创建一个包含两个列表作为其成员的类，然后可以使用列表返回该类对象。