似乎只检查月份就可以了：
private static final String seasons[] = {
"Winter", "Winter", "Spring", "Spring", "Summer", "Summer",
"Summer", "Summer", "Fall", "Fall", "Winter", "Winter"
};
public String getSeason( Date date ) {
return seasons[ date.getMonth() ];
}
// As stated above, getMonth() is deprecated, but if you start with a Date,
// you'd have to convert to Calendar before continuing with new Java,
// and that's not fast.
这里有一些很好的答案，但它们已经过时了。java.time 类使这项工作更容易。
Java 8 及更高版本中内置的java.time类已取代了与最早版本的 Java 捆绑在一起的麻烦的旧类。请参阅Oracle 教程。大部分功能已在 ThreeTen-Backport 中向后移植到 Java 6 和 7，并在ThreeTenABP中进一步适应 Android 。
Month鉴于此处使用整月定义季节，我们可以使用方便的enum。这样的枚举值比单纯的整数值 (1-12) 要好，因为它们是类型安全的，并且可以保证您得到有效值。Month
EnumSetAnEnumSet是一种跟踪枚举值子集的快速执行且内存紧凑的方法。
EnumSet<Month> spring = EnumSet.of( Month.MARCH , Month.APRIL );
EnumSet<Month> summer = EnumSet.of( Month.MAY , Month.JUNE , Month.JULY , Month.AUGUST );
EnumSet<Month> fall = EnumSet.of( Month.SEPTEMBER , Month.OCTOBER );
EnumSet<Month> winter = EnumSet.of( Month.NOVEMBER , Month.DECEMBER , Month.JANUARY , Month.FEBRUARY );
例如，我们获取特定时区的当前时刻。
ZoneId zoneId = ZoneId.of( "America/Montreal" );
ZonedDateTime zdt = ZonedDateTime.now( zoneId );
询问它的日期时间值Month。
Month month = Month.from( zdt );
通过调用查找哪个季节EnumSet具有该特定月份值contains。
if ( spring.contains( month ) ) {
…
} else if ( summer.contains( month ) ) {
…
} else if ( fall.contains( month ) ) {
…
} else if ( winter.contains( month ) ) {
…
} else {
// FIXME: Handle reaching impossible point as error condition.
}
如果你在你的代码库中使用这个季节的想法，我建议定义你自己的枚举，“季节”。
基本枚举很简单：public enum Season { SPRING, SUMMER, FALL, WINTER; }. 但是我们还添加了一个静态方法of来查找哪个月份映射到哪个季节。
package work.basil.example;
import java.time.Month;
public enum Season {
SPRING, SUMMER, FALL, WINTER;
static public Season of ( final Month month ) {
switch ( month ) {
// Spring.
case MARCH: // Java quirk: An enum switch case label must be the unqualified name of an enum. So cannot use `Month.MARCH` here, only `MARCH`.
return Season.SPRING;
case APRIL:
return Season.SPRING;
// Summer.
case MAY:
return Season.SUMMER;
case JUNE:
return Season.SUMMER;
case JULY:
return Season.SUMMER;
case AUGUST:
return Season.SUMMER;
// Fall.
case SEPTEMBER:
return Season.FALL;
case OCTOBER:
return Season.FALL;
// Winter.
case NOVEMBER:
return Season.WINTER;
case DECEMBER:
return Season.WINTER;
case JANUARY:
return Season.WINTER;
case FEBRUARY:
return Season.WINTER;
default:
System.out.println ( "ERROR." ); // FIXME: Handle reaching impossible point as error condition.
return null;
}
}
}
或者使用 Java 14 的 switch 表达式功能 ( JEP 361 )。
package work.basil.example;
import java.time.Month;
import java.util.Objects;
public enum Season
{
SPRING, SUMMER, FALL, WINTER;
static public Season of ( final Month month )
{
Objects.requireNonNull( month , "ERROR - Received null where a `Month` is expected. Message # 0ac03df9-1c5a-4c2d-a22d-14c40e25c58b." );
return
switch ( Objects.requireNonNull( month ) )
{
// Spring.
case MARCH , APRIL -> Season.SPRING;
// Summer.
case MAY , JUNE , JULY , AUGUST -> Season.SUMMER;
// Fall.
case SEPTEMBER , OCTOBER -> Season.FALL;
// Winter.
case NOVEMBER , DECEMBER , JANUARY , FEBRUARY -> Season.WINTER;
}
;
}
}
以下是如何使用该枚举。
ZoneId zoneId = ZoneId.of ( "America/Montreal" );
ZonedDateTime zdt = ZonedDateTime.now ( zoneId );
Month month = Month.from ( zdt );
Season season = Season.of ( month );
转储到控制台。
System.out.println ( "zdt: " + zdt + " | month: " + month + " | season: " + season );
zdt: 2016-06-25T18:23:14.695-04:00[美国/蒙特利尔] | 月份：六月 | 季节：夏季
好吧，它可能很简单
String getSeason(int month) {
switch(month) {
case 11:
case 12:
case 1:
case 2:
return "winter";
case 3:
case 4:
return "spring";
case 5:
case 6:
case 7:
case 8:
return "summer";
default:
return "autumn";
}
}
我在评论中被指责为更好的解决方案：枚举：
public static Enum Season {
WINTER(Arrays.asList(11,12,1,2)),
SPRING(Arrays.asList(3,4)),
SUMMER(Arrays.asList(5,6,7,8)),
AUTUMN(Arrays.asList(9,10));
Season(List<Integer> months) {
this.monthlist = months;
}
private List<Integer> monthlist;
public boolean inSeason(int month) {
return this.monthlist.contains(month); // if months are 0 based, then insert +1 before the )
}
public static Season seasonForMonth(int month) {
for(Season s: Season.values()) {
if (s.inSeason(month))
return s;
}
throw new IllegalArgumentException("Unknown month");
}
}
我感到受宠若惊，但受宠若惊。所以我会做的。
这不仅检查月份，而且检查月份中的某一天。
import java.util.*
public String getSeason(Date today, int year){
// the months are one less because GC is 0-based for the months, but not days.
// i.e. 0 = January.
String returnMe = "";
GregorianCalender dateToday = new GregorianCalender(year, today.get(Calender.MONTH_OF_YEAR), today.get(Calender.DAY_OF_MONTH);
GregorianCalender springstart = new GregorianCalender(year, 2, 1);
GregorianCalender springend = new GregorianCalender(year, 3, 30);
GregorianCalender summerstart = new GregorianCalender(year, 4, 1);
GregorianCalender summerend = new GregorianCalender(year, 7, 31);
GregorianCalender fallstart = new GregorianCalender(year, 8, 1);
GregorianCalender fallend = new GregorianCalender(year, 9, 31);
GregorianCalender winterstart = new GregorianCalender(year, 10, 1);
GregorianCalender winterend = new GregorianCalender(year, 1, 28);
if ((dateToday.after(springstart) && dateToday.before(springend)) || dateToday.equals(springstart) || dateToday.equals(springend)){
returnMe = "Spring";
else if ((dateToday.after(summerstart) && dateToday.before(summerend)) || dateToday.equals(summerstart) || dateToday.equals(summerend)){
returnMe = "Summer";
else if ((dateToday.after(fallstart) && dateToday.before(fallend)) || dateToday.equals(fallstart) || dateToday.equals(fallend)){
returnMe = "Fall";
else if ((dateToday.after(winterstart) && dateToday.before(winterend)) || dateToday.equals(winterstart) || dateToday.equals(winterend)){
returnMe = "Winter";
else {
returnMe = "Invalid";
}
return returnMe;
}
我敢肯定这很可怕，并且可以改进。在评论中告诉我。
public class lab6project1 {
public static void main(String[] args) {
Scanner keyboard = new Scanner(System.in);
System.out.println("This program reports the season for a given day and month");
System.out.println("Please enter the month and day as integers with a space between the month and day");
int month = keyboard.nextInt();
int day = keyboard.nextInt();
if ((month == 1) || (month == 2)) {
System.out.println("The season is Winter");
} else if ((month == 4) || (month == 5)) {
System.out.println("The season is Spring");
} else if ((month == 7) || (month == 8)) {
System.out.println("The season is Summer");
} else if ((month == 10) || (month == 11)) {
System.out.println("The season is Fall");
} else if ((month == 3) && (day <= 19)) {
System.out.println("The season is Winter");
} else if (month == 3) {
System.out.println("The season is Spring");
} else if ((month == 6) && (day <= 20)) {
System.out.println("The season is Spring");
} else if (month == 6) {
System.out.println("The season is Summer");
} else if ((month == 9) && (day <= 20)) {
System.out.println("The season is Summer");
} else if (month == 9) {
System.out.println("The season is Autumn");
} else if ((month == 12) && (day <= 21)) {
System.out.println("The season is Autumn");
} else if (month == 12) {
System.out.println("The season is Winter");
}
}
}
尝试使用哈希表或枚举。您可以将日期转换为某个值（jan 1 为 1，...），然后为某个字段创建 bin。或者您可以对月份进行枚举。{一月：冬天，二月：冬天，...七月：夏天，等等}
由于在此范围内所有季节都是整月，因此您可以使用日期的月份进行切换：
switch (date.getMonth()) {
case Calendar.JANUARY:
case Calendar.FEBRUARY:
return "winter";
case Calendar.MARCH:
return "spring";
//etc
}
我建议使用所有 12 个日历常量来完成整个切换，而不是最后一个的默认值。然后，您可以确保您的输入是正确的，例如
default:
throw new IllegalArgumentException();
在末尾。
根据您的用例，您可能还希望在季节中使用 Enum，而不是简单的字符串。
请注意 Date.getMonth() 方法已弃用，您应该改用 java.util.Calendar.get(Calendar.MONTH) 。（只需使用 calendar.setDate(yourDate) 将日期转换为日历）
简单的解决方案
Calendar calendar = Calendar.getInstance();
calendar.setTimeInMillis(timeInMills);
int month = calendar.get(Calendar.MONTH);
CurrentSeason = month == 11 ? 0 : (month + 1) / 3;
您的问题的标题非常笼统，因此大多数用户首先会想到天文季节。即使您的问题的详细内容仅限于自定义的日期范围，但这种限制可能只是由于无法计算天文情况造成的，所以我也敢于针对天文场景发布这个老问题的答案。
这里的大多数答案仅基于整月。我在这里举两个例子来解决天文季节和基于任意日期范围的季节。
在这里，我们肯定需要额外的信息，具体的时区或偏移量，否则我们无法java.util.Date使用月份和日期的组合将瞬间（如您输入的老式实例）转换为本地表示。为简单起见，我假设系统时区。
// your input
java.util.Date d = new java.util.Date();
ZoneId tz = ZoneId.systemDefault();
// extract the relevant month-day
ZonedDateTime zdt = d.toInstant().atZone(tz);
MonthDay md = MonthDay.of(zdt.getMonth(), zdt.getDayOfMonth());
// a definition with day-of-month other than first is possible here
MonthDay beginOfSpring = MonthDay.of(3, 1);
MonthDay beginOfSummer = MonthDay.of(5, 1);
MonthDay beginOfAutumn = MonthDay.of(9, 1);
MonthDay beginOfWinter = MonthDay.of(11, 1);
// determine the season
Season result;
if (md.isBefore(beginOfSpring)) {
result = Season.WINTER;
} else if (md.isBefore(beginOfSummer)) {
result = Season.SPRING;
} else if (md.isBefore(beginOfAutumn)) {
result = Season.SUMMER;
} else if (md.isBefore(beginOfWinter)) {
result = Season.FALL;
} else {
result = Season.WINTER;
}
System.out.println(result);
我使用了一个简单的帮助枚举，例如public enum Season { SPRING, SUMMER, FALL, WINTER; }.
在这里，我们还需要一个额外的信息，即季节是在北半球还是在南半球。我的库Time4J基于使用 v5.2 版本的预定义枚举AstronomicalSeason提供以下解决方案：
// your input
java.util.Date d = new java.util.Date();
boolean isSouthern = false;
Moment m = TemporalType.JAVA_UTIL_DATE.translate(d);
AstronomicalSeason result = AstronomicalSeason.of(m);
if (isSouthern) { // switch to southern equivalent if necessary
result = result.onSouthernHemisphere();
}
System.out.println(result);
如果只需要北半球的季节编号：
/**
* @return 1 - winter, 2 - spring, 3 - summer, 4 - autumn
*/
private static int getDateSeason(LocalDate date) {
return date.plus(1, MONTHS).get(IsoFields.QUARTER_OF_YEAR);
}
通过如何发现给定日期的季度？.
以下是如何计算给定日期的季节界限：
private static LocalDate atStartOfSeason(LocalDate date) {
return date.plus(1, MONTHS).with(IsoFields.DAY_OF_QUARTER, 1).minus(1, MONTHS);
}
private static LocalDate afterEndOfSeason(LocalDate date) {
return atStartOfSeason(date).plus(3, MONTHS);
}
import java.util.Scanner;
public class Season {
public static void main (String[] args) {
Scanner sc = new Scanner(System.in);
System.out.println("Enter the month:");
int mon=sc.nextInt();
if(mon>12||mon<1)
{
System.out.println("Invalid month");
}
else if(mon>=3&&mon<=5)
{
System.out.println("Season:Spring");
}
else if(mon>=6&&mon<=8)
{
System.out.println("Season:Summer");
}
else if(mon>=9&&mon<=11)
{
System.out.println("Season:Autumn");
}
else if(mon==12||mon==1||mon==2)
{
System.out.println("Season:Winter");
}
}
}