如何找到我当前的时间介于今天的时间和Tommorow在JAVA的时间之间

Question

我正在尝试确定当前时间(例如 19：30：00(是否在第二天 19：00：00 和 03：00：00 之间，但我的代码失败了。 我的代码在此情况下失败 如果是，我可以使用日期到露营时间，请告诉我如何

import java.util.Calendar;
import java.text.SimpleDateFormat;
public class DateUtils {
// format 24hre ex. 12:12 , 17:15
private static String  HOUR_FORMAT = "HH:mm";
private DateUtils() {    }
public static String getCurrentHour() {
Calendar cal = Calendar.getInstance();
SimpleDateFormat sdfHour = new SimpleDateFormat(HOUR_FORMAT);
String hour = sdfHour.format(cal.getTime());
return hour;
}
/**
* @param  target  hour to check
* @param  start   interval start
* @param  end     interval end
* @return true    true if the given hour is between
*/
public static boolean isHourInInterval(String target, String start, String end) {
return ((target.compareTo(start) >= 0)
&& (target.compareTo(end) <= 0));
}
/**
* @param  start   interval start
* @param  end     interval end
* @return true    true if the current hour is between
*/
public static boolean isNowInInterval(String start, String end) {
return DateUtils.isHourInInterval
(DateUtils.getCurrentHour(), start, end);
}
//    TEST
public static void main (String[] args) {
String now = DateUtils.getCurrentHour();
String start = "14:00";
String end   = "14:26";
System. out.println(now + " between " + start + "-" + end + "?");
System. out.println(DateUtils.isHourInInterval(now,start,end));
/*
* output example :
*   21:01 between 14:00-14:26?
*   false
*
*/
}
}

Answer 1

java.time.LocalTime是你的朋友。下面是一个快速示例，当然可以做得更短一些。

void test(){
var tz = ZoneId.of("CET");
var anyDate = LocalDate.of(2019,12,4);
var x = ZonedDateTime.of(LocalDateTime.of(anyDate, LocalTime.of(18,59)),tz).toInstant();
System.out.println(testTime(Clock.fixed( ZonedDateTime.of(LocalDateTime.of(anyDate, LocalTime.of(18,59)),tz).toInstant(),tz)));
System.out.println(testTime(Clock.fixed( ZonedDateTime.of(LocalDateTime.of(anyDate, LocalTime.of(19,01)),tz).toInstant(),tz)));
System.out.println(testTime(Clock.fixed( ZonedDateTime.of(LocalDateTime.of(anyDate, LocalTime.of(00,00)),tz).toInstant(),tz)));
System.out.println(testTime(Clock.fixed( ZonedDateTime.of(LocalDateTime.of(anyDate, LocalTime.of(02,59)),tz).toInstant(),tz)));
System.out.println(testTime(Clock.fixed( ZonedDateTime.of(LocalDateTime.of(anyDate, LocalTime.of(03,01)),tz).toInstant(),tz)));
}
boolean testTime(Clock clock){
var evening =LocalTime.of(19,00);
var midnight =LocalTime.of(00,00);
var night =LocalTime.of(03,00);
LocalTime wallTime = LocalTime.now(clock);
return (wallTime.isAfter(evening) && wallTime.isBefore(midnight.minusNanos(1))) ||  (midnight.isBefore(wallTime) && wallTime.isBefore(night)) || wallTime.equals(midnight);
}