使用java编写一个日期转换工具类

public class DateUtil {

public static String formatDate(Date date, String pattern) {
    SimpleDateFormat sdf = new SimpleDateFormat(pattern);
    return sdf.format(date);
}

public static Date parseDate(String dateStr, String pattern) throws ParseException {
    SimpleDateFormat sdf = new SimpleDateFormat(pattern);
    return sdf.parse(dateStr);
}

public static String formatDateWithDefaultPattern(Date date) {
    return formatDate(date, "yyyy-MM-dd HH:mm:ss");
}

public static Date parseDateWithDefaultPattern(String dateStr) throws ParseException {
    return parseDate(dateStr, "yyyy-MM-dd HH:mm:ss");
}

}

使用示例： Date now = new Date(); String dateStr = DateUtil.formatDate(now, "yyyy-MM-dd"); System.out.println(dateStr); // 输出：2022-05-28 Date parsedDate = DateUtil.parseDate(dateStr, "yyyy-MM-dd"); System.out.println(parsedDate); // 输出：Sat May 28 00:00:00 CST 2022 String nowStr = DateUtil.formatDateWithDefaultPattern(now); System.out.println(nowStr); // 输出：2022-05-28 10:30:00 Date parsedNow = DateUtil.parseDateWithDefaultPattern(nowStr); System.out.println(parsedNow); // 输出：Sat May 28 10:30:00 CST 2022