在Java中，我们经常需要计算特定时间范围的开始和结束时间，例如当天、当周、当月、当季度和当年。本文将演示如何使用Java编写一个时间范围计算器，返回包含开始和结束时间的列表。
首先，我们可以使用Java 8引入的java.time包，其中包含了现代的日期时间处理类。以下是基于这个包的实现：
import java.time.format.DateTimeFormatter;
import java.util.ArrayList;
import java.util.List;
public class TimeRangeCalculator {
public static void main(String[] args) {
List<LocalDateTime> timeRange = getTimeRange(1);
for (LocalDateTime dateTime : timeRange) {
System.out.println(dateTime.format(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")));
}
// 同样的方式可以应用于其他参数
}
public static List<LocalDateTime> getTimeRange(int param) {
LocalDateTime now = LocalDateTime.now();
List<LocalDateTime> result = new ArrayList<>();
switch (param) {
case 1:
result.add(now.withHour(0).withMinute(0).withSecond(0));
result.add(now.withHour(23).withMinute(59).withSecond(59));
break;
case 2:
result.add(now.with(now.toLocalDate().with(java.time.DayOfWeek.MONDAY)).withHour(0).withMinute(0).withSecond(0));
result.add(now.with(now.toLocalDate().with(java.time.DayOfWeek.SUNDAY)).withHour(23).withMinute(59).withSecond(59));
break;
case 3:
result.add(now.with(now.toLocalDate().withDayOfMonth(1)).withHour(0).withMinute(0).withSecond(0));
result.add(now.with(now.toLocalDate().plusMonths(1).withDayOfMonth(1)).withHour(23).withMinute(59).withSecond(59));
break;
case 4:
int currentMonth = now.getMonthValue();
int quarterStartMonth = (currentMonth - 1) / 3 * 3 + 1;
result.add(now.with(now.toLocalDate().withMonth(quarterStartMonth).withDayOfMonth(1)).withHour(0).withMinute(0).withSecond(0));
result.add(now.with(now.toLocalDate().withMonth(quarterStartMonth + 2).withDayOfMonth(1).plusMonths(1).minusDays(1)).withHour(23).withMinute(59).withSecond(59));
break;
case 5:
result.add(now.with(now.toLocalDate().withDayOfYear(1)).withHour(0).withMinute(0).withSecond(0));
result.add(now.with(now.toLocalDate().plusYears(1).withDayOfYear(1).minusDays(1)).withHour(23).withMinute(59).withSecond(59));
break;
default:
// 处理无效参数的逻辑
break;
}
return result;
}
}
其次，我们也可以使用传统的Calendar类。以下是基于Calendar的实现：
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.List;
public class TimeRangeCalculator {
public static void main(String[] args) {
List<Calendar> timeRange = getTimeRange(1);
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
for (Calendar calendar : timeRange) {
System.out.println(dateFormat.format(calendar.getTime()));
}
// 同样的方式可以应用于其他参数
}
public static List<Calendar> getTimeRange(int param) {
Calendar now = Calendar.getInstance();
List<Calendar> result = new ArrayList<>();
switch (param) {
case 1:
result.add(getStartOfDay(now));
result.add(getEndOfDay(now));
break;
case 2:
result.add(getStartOfWeek(now));
result.add(getEndOfWeek(now));
break;
case 3:
result.add(getStartOfMonth(now));
result.add(getEndOfMonth(now));
break;
case 4:
result.add(getStartOfQuarter(now));
result.add(getEndOfQuarter(now));
break;
case 5:
result.add(getStartOfYear(now));
result.add(getEndOfYear(now));
break;
default:
// 处理无效参数的逻辑
break;
}
return result;
}
private static Calendar getStartOfDay(Calendar calendar) {
Calendar startOfDay = (Calendar) calendar.clone();
startOfDay.set(Calendar.HOUR_OF_DAY, 0);
startOfDay.set(Calendar.MINUTE, 0);
startOfDay.set(Calendar.SECOND, 0);
return startOfDay;
}
private static Calendar getEndOfDay(Calendar calendar) {
Calendar endOfDay = (Calendar) calendar.clone();
endOfDay.set(Calendar.HOUR_OF_DAY, 23);
endOfDay.set(Calendar.MINUTE, 59);
endOfDay.set(Calendar.SECOND, 59);
return endOfDay;
}
private static Calendar getStartOfWeek(Calendar calendar) {
Calendar startOfWeek = (Calendar) calendar.clone();
startOfWeek.set(Calendar.DAY_OF_WEEK, startOfWeek.getFirstDayOfWeek());
return getStartOfDay(startOfWeek);
}
private static Calendar getEndOfWeek(Calendar calendar) {
Calendar endOfWeek = (Calendar) calendar.clone();
endOfWeek.set(Calendar.DAY_OF_WEEK, endOfWeek.getActualMaximum(Calendar.DAY_OF_WEEK));
return getEndOfDay(endOfWeek);
}
private static Calendar getStartOfMonth(Calendar calendar) {
Calendar startOfMonth = (Calendar) calendar.clone();
startOfMonth.set(Calendar.DAY_OF_MONTH, 1);
return getStartOfDay(startOfMonth);
}
private static Calendar getEndOfMonth(Calendar calendar) {
Calendar endOfMonth = (Calendar) calendar.clone();
endOfMonth.set(Calendar.DAY_OF_MONTH, endOfMonth.getActualMaximum(Calendar.DAY_OF_MONTH));
return getEndOfDay(endOfMonth);
}
private static Calendar getStartOfQuarter(Calendar calendar) {
Calendar startOfQuarter = (Calendar) calendar.clone();
int currentMonth = startOfQuarter.get(Calendar.MONTH);
int quarterStartMonth = (currentMonth / 3) * 3;
startOfQuarter.set(Calendar.MONTH, quarterStartMonth);
startOfQuarter.set(Calendar.DAY_OF_MONTH, 1);
return getStartOfDay(startOfQuarter);
}
private static Calendar getEndOfQuarter(Calendar calendar) {
Calendar endOfQuarter = (Calendar) calendar.clone();
int currentMonth = endOfQuarter.get(Calendar.MONTH);
int quarterEndMonth = ((currentMonth / 3) + 1) * 3 - 1;
endOfQuarter.set(Calendar.MONTH, quarterEndMonth);
endOfQuarter.set(Calendar.DAY_OF_MONTH, endOfQuarter.getActualMaximum(Calendar.DAY_OF_MONTH));
return getEndOfDay(endOfQuarter);
}
private static Calendar getStartOfYear(Calendar calendar) {
Calendar startOfYear = (Calendar) calendar.clone();
startOfYear.set(Calendar.DAY_OF_YEAR, 1);
return getStartOfDay(startOfYear);
}
private static Calendar getEndOfYear(Calendar calendar) {
Calendar endOfYear = (Calendar) calendar.clone();
endOfYear.set(Calendar.DAY_OF_YEAR, endOfYear.getActualMaximum(Calendar.DAY_OF_YEAR));
return getEndOfDay(endOfYear);
}
}
这两个实现都提供了灵活的方式，根据不同的参数返回相应时间范围的开始和结束时间。你可以根据项目需求和个人偏好选择使用java.time或Calendar。这个时间范围计算器可以轻松地扩展到其他时间单位和需求。