到目前为止，我有一个代码可以计算输入一年的复活节的日期。我需要对其进行更改，以便为您提供多年的多个日期（您输入2年而不是介于两者之间的所有日期）。希望有道理！
我不确定我要在这里做什么。我们已经学习了forloops（注意：我们只是在学习Java），所以我尝试为代码放一个forloop，但是由于我不确定这样做是如何实现的，所以简短了。
import java.util.Scanner;
public static void main(String[] args) {
System.out.print("Please enter a year to calculate Easter Sunday\n>");
Scanner sc = new Scanner(System.in);//imports java.util.Scanner to the library
int aNumber = sc.nextInt();//saves next inputted number as "aNumber"
while (aNumber <=0){//while statement to make sure inputted year is positive
System.out.println("Please enter a postive year: ");
aNumber = sc.nextInt();
}
int a = aNumber % 19,
b = aNumber / 100,
c = aNumber % 100,
d = b / 4,
e = b % 4,
g = (8 * b + 13) / 25,
h = (19 * a + b - d - g + 15) % 30,
j = c / 4,
k = c % 4,
m = (a + 11 * h) / 319,
r = (2 * e + 2 * j - k - h + m + 32) % 7,
month = (h - m + r + 90) / 25, //determines month as a number
date = (h - m + r + month + 19) % 32;//determines date
String test;
switch(month)//switch case to convert "month" to a string
{
case 1:
test = "January ";
break;
case 2:
test = "February ";
break;
case 3:
test = "March ";
break;
case 4:
test = "April ";
break;
case 5:
test = "May ";
break;
case 6:
test = "June ";
break;
case 7:
test = "July ";
break;
case 8:
test = "August ";
break;
case 9:
test = "September ";
break;
case 10:
test = "October ";
break;
case 11:
test = "November ";
break;
case 12:
test = "December ";
break;
default:
test = "error";
}
System.out.println("In " + aNumber + ", Easter Sunday will be on " + test + "" + date + ".");//displays year,date and month of Easter Sunday
}
我打算在您输入的两年之间每年获得多个日期。
答案 0 :(得分：1)
好吧，只要您的代码可以正确计算复活节，就可以针对以下目标：
static String printEasterFor(int aNumber) {
int a = aNumber % 19,
b = aNumber / 100,
c = aNumber % 100,
d = b / 4,
e = b % 4,
g = (8 * b + 13) / 25,
h = (19 * a + b - d - g + 15) % 30,
j = c / 4,
k = c % 4,
m = (a + 11 * h) / 319,
r = (2 * e + 2 * j - k - h + m + 32) % 7,
month = (h - m + r + 90) / 25, //determines month as a number
date = (h - m + r + month + 19) % 32;//determines date
String test;
switch(month)//switch case to convert "month" to a string
{
case 1:
test = "January ";
break;
case 2:
test = "February ";
break;
case 3:
test = "March ";
break;
case 4:
test = "April ";
break;
case 5:
test = "May ";
break;
case 6:
test = "June ";
break;
case 7:
test = "July ";
break;
case 8:
test = "August ";
break;
case 9:
test = "September ";
break;
case 10:
test = "October ";
break;
case 11:
test = "November ";
break;
case 12:
test = "December ";
break;
default:
test = "error";
}
return "In " + aNumber + ", Easter Sunday will be on " + test + "" + date + ".";//displays year,date and month of Easter Sunday
}
static List<String> showEasterBetween(int start, int end) {
List<String> result = new ArrayList<>();
IntStream.range(start, end).forEach(year -> result.add(printEasterFor(year)));
return result;
}
然后您这样称呼：
public static void main(String[] args) {
int startYear = 2005;
int endYear = 2025;
List<String> easters = showEasterBetween(startYear, endYear);
}
作为改进，您的方法printEasterFor可以返回LocalDate对象，而不是打印字符串，但我希望您能理解。
答案 1 :(得分：1)
Answer by mate00似乎正确。如此处所述，您应该使用 java.time 类型。让我们采用其他答案中所示的代码，并使其与现代的日期时间类更加完美。为了清楚起见，我们还更改了一些名称。
我们有一个Year类。使用该Year类型作为方法的参数使代码更具自记录性。
Year year = Year.of( 2019 ) ;
我们有LocalDate表示仅日期的值，没有日期和时区。
LocalDate localDate = LocalDate.of( 2019 , Month.JANUARY , 23 ) ;
我们有一个Month枚举，为一年的每个月预定义一个对象。使用Month枚举，我们可以将您长的switch语句折叠成一两行。 Month.values()方法生成一个由枚举预实例化的所有对象的数组。我们可以按数字从该数组中选择一个月。但是我们必须使用恼人的从零开始的索引计数。从1-12减去1得到0-11。
Month month = Month.values()[ 1-1 ]; // Get `Month.JANUARY` object for month number 1 (index number 0).
这里是一个完整的示例类Easter，其中有一对方法重载of（经过一年或两年）。给定已建立的java.time naming conventions，也许forYear和forYears可能是更好的方法名称。理想名称为for，但这是for循环的保留关键字。
当心：我尚未测试此代码的结果。使用风险自负。
package work.basil.example;
import java.util.ArrayList;
import java.util.List;
import java.util.Objects;
import java.time.*;
public class Easter
{
static LocalDate of ( Year year )
{
int yearNumber = year.getValue(); // Convert from object to simple integer.
int a = yearNumber % 19,
b = yearNumber / 100,
c = yearNumber % 100,
d = b / 4,
e = b % 4,
g = ( 8 * b + 13 ) / 25,
h = ( 19 * a + b - d - g + 15 ) % 30,
j = c / 4,
k = c % 4,
m = ( a + 11 * h ) / 319,
r = ( 2 * e + 2 * j - k - h + m + 32 ) % 7,
monthNumber = ( h - m + r + 90 ) / 25, //determines month as a number
dayOfMonth = ( h - m + r + monthNumber + 19 ) % 32;//determines date
int monthIndex = ( monthNumber - 1 ); // Convert from ordinal number to index number, zero-based for accessing an array in Java.
Month month = Month.values()[ monthIndex ]; // Get the `Month` enum object for this month index. Throws an exception if the month index is out of range of 0-11.
LocalDate easter = LocalDate.of( yearNumber , month , dayOfMonth );
return easter;
}
static List < LocalDate > of ( Year start , Year stop )
{
Objects.requireNonNull( start );
Objects.requireNonNull( stop );
if ( stop.isBefore( start ) ) // Verify the stop year is not before the start year. Defensive programming.
{
throw new IllegalArgumentException( "The stop year cannot be before the start year. Message # 296232f7-0c6e-49c2-a462-851aa0b30352." );
}
List < LocalDate > easters = new ArrayList <>();
Year year = start;
while ( year.isBefore( stop ) )
{
LocalDate easter = Easter.of( year ); // Determine the date of Easter for this particular year.
easters.add( easter );
// Prepare for next loop.
year = year.plusYears( 1L ); // Increment to the next year in succession.
}
return easters;
}
public static void main ( String[] args )
{
List < LocalDate > easters = Easter.of( Year.of( 2005 ) , Year.of( 2010 ) );
System.out.println( "easters.toString(): " + easters );
}
}
运行时。
easters.toString（）：[2005-03-27、2006-04-16、2007-04-08、2008-03-23、2009-04-12]
在此特定例程中，我们真的不需要Month枚举。我们可以将monthNumber整数传递给工厂方法LocalDate::of。
LocalDate easter = LocalDate.of( yearNumber , monthNumber , dayOfMonth );
要生成表示这些LocalDate对象值的字符串，请使用DateTimeFormatter类，尤其是其ofLocalizedDate方法。搜索堆栈溢出以获取更多信息，因为已经有很多次了。
DateTimeFormatter f = DateTimeFormatter.ofLocalizedDate( FormatStyle.FULL ).withLocale( Locale.CANADA_FRENCH) ; // Or `Locale.US` etc.
String output = localDate.format( f ) ;
dimanche 2005年3月27日