JAVA:如何根据字段对列表进行排序
我有下面的列表,我想根据日期对整个列表进行排序,我该怎么做JAVA:如何根据字段对列表进行排序,java,sorting,date,time,Java,Sorting,Date,Time,我有下面的列表,我想根据日期对整个列表进行排序,我该怎么做 List<DevicePing> devicePing=Arrays.asList( new DevicePing(1L,2017-11-21 10:10:10.0), new DevicePing(2L,2017-11-21 10:00:00.0), new DevicePing(3L,2017-11-21 10:15:10.0
List<DevicePing> devicePing=Arrays.asList(
new DevicePing(1L,2017-11-21 10:10:10.0),
new DevicePing(2L,2017-11-21 10:00:00.0),
new DevicePing(3L,2017-11-21 10:15:10.0),
new DevicePing(4L,2017-11-21 09:30:10.0),
new DevicePing(5L,2017-11-21 09:45:10.0),
new DevicePing(6L,2017-11-21 09:50:10.0),
new DevicePing(7L,2017-11-21 09:55:10.0);
尝试使用以下方法对其进行排序:
devicePing.sort(Comparator.comparing(devicePing::getDateTime))代码>从最旧到最新排序?从最新到最旧使用比较器-而且您没有显示完整的代码。请阅读并尝试使用具有相同代码的LocalDateTime。public void calculateTimesheet(RiderLocation RiderLocation,List devicePing,List riderAvailability){devicePing.sort(Comparator.comparing(devicePing::getDate));for(devicePing dp:devicePing){System.out.println(“dp:+dp”)}
我尝试了您的示例,但它打印的是相同的数据,而不是经过排序的数据DevicePing::getDateTime
,您的所有日期都在同一天。使用日期和时间实际上它是一个时间戳请检查我编辑的问题Java类型是什么<代码>本地日期时间
<代码>日期?我想根据时间戳对列表进行排序
Collections.sort(myList, new Comparator<MyObject>() {
public int compare(MyObject o1, MyObject o2) {
return o1.getDateTime().compareTo(o2.getDateTime());
}
});
public void calculateTimesheet(RiderLocation riderLocation,List<DevicePing> devicePing,List<RiderAvailability> riderAvailability)
{
devicePing.sort(Comparator.comparing(DevicePing::getDate));
for(DevicePing dp:devicePing)
{
System.out.println("dp: " + dp);
}
}
@Entity
public class DevicePing {
public DevicePing(Long id ,Date createdAt) {
this.id = id;
this.createdAt = createdAt;
}
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
@ManyToOne
private User rider;
@Column( nullable = false,columnDefinition = "TIMESTAMP DEFAULT CURRENT_TIMESTAMP")
@Temporal(TemporalType.TIMESTAMP)
private Date date;
//getter nad setter
}