通过可嵌入的 Java 类流式传输

Question

我有一个带有实体的可嵌入类

@Embeddable
public class EventId implements Serializable {
    private Long id;
    private Date updateDateTime;
}

@Entity
public class Event {
    @EmbeddedId
    private EventId id;
    private String name;

}

How to get below map of EventId.id(Long),Event from steam for given event list

List<Event> events;
Map<Long, Event> eventMap = events.stream... ?

Answer 1

我猜你的目的是按 EventId.id 对

List<Event> events

进行排序，这样你就可以像这样使用

Collectors.groupingBy

：

Map<Long, List<Event>> collect = events.stream().collect(Collectors.groupingBy(Event -> Event.getId().getId()));