java根据起止时间按天拆分日期

A：

实现这个功能可以使用Java标准库中的LocalDate类。具体实现步骤如下：

1. 定义起止时间和日期格式

String startDateStr = "2021-01-01";
String endDateStr = "2021-01-15";
DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd");

2. 转换起止时间为LocalDate类型

LocalDate startDate = LocalDate.parse(startDateStr, formatter);
LocalDate endDate = LocalDate.parse(endDateStr, formatter);

3. 循环遍历日期范围，按天拆分日期

List<LocalDate> dateList = new ArrayList<>();
while (!startDate.isAfter(endDate)) {
    dateList.add(startDate);
    startDate = startDate.plusDays(1);
}

4. 输出拆分后的日期列表

for (LocalDate date : dateList) {
    System.out.println(date.format(formatter));
}

完整代码示例：

import java.time.LocalDate;
import java.time.format.DateTimeFormatter;
import java.util.ArrayList;
import java.util.List;

public class SplitDateByDay {

    public static void main(String[] args) {
        String startDateStr = "2021-01-01";
        String endDateStr = "2021-01-15";
        DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd");

        LocalDate startDate = LocalDate.parse(startDateStr, formatter);
        LocalDate endDate = LocalDate.parse(endDateStr, formatter);

        List<LocalDate> dateList = new ArrayList<>();
        while (!startDate.isAfter(endDate)) {
            dateList.add(startDate);
            startDate = startDate.plusDays(1);
        }

        for (LocalDate date : dateList) {
            System.out.println(date.format(formatter));
        }
    }
}