输入startDateendDate设置固定格式YYYY-MM-DD HHmmssstartDate为YYYY-MM-DD 000000endDate为YYYY-MM-DD 235959java代码实现

import java.text.SimpleDateFormat; import java.util.Calendar; import java.util.Date;

public class DateFormatExample {

public static void main(String[] args) {
    String startDate = "2022-01-01";
    String endDate = "2022-01-31";
    
    String formattedStartDate = formatDateTime(startDate, "00:00:00");
    String formattedEndDate = formatDateTime(endDate, "23:59:59");
    
    System.out.println("Formatted Start Date: " + formattedStartDate);
    System.out.println("Formatted End Date: " + formattedEndDate);
}

public static String formatDateTime(String date, String time) {
    try {
        SimpleDateFormat inputFormat = new SimpleDateFormat("yyyy-MM-dd");
        Date parsedDate = inputFormat.parse(date);
        
        Calendar calendar = Calendar.getInstance();
        calendar.setTime(parsedDate);
        
        SimpleDateFormat outputFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        return outputFormat.format(calendar.getTime()) + " " + time;
    } catch (Exception e) {
        e.printStackTrace();
        return null;
    }
}

}

输出： Formatted Start Date: 2022-01-01 00:00:00 Formatted End Date: 2022-01-31 23:59:5