时间的类型的相互转换（date/String）及时区的比较

String ->Date ->String

    @Test
    public void date() throws ParseException{
        String sdate = "01-01-2025";
        SimpleDateFormat sdf = new SimpleDateFormat("dd-MM-yyyy");
        Date date = sdf.parse(sdate);
        System.out.println("--date--"+date);
        
        sdate = (new SimpleDateFormat("yyyy-MM-dd")).format(date);
        
        System.out.println("---String---"+sdate);
    }

打印结果：

--date--Wed Jan 01 00:00:00 CST 2025
---String---2025-01-01

XMLGregorianCalendar -> Date -> String 

    /** 
     * 将Date类转换为XMLGregorianCalendar 
     * @param date 
     * @return  
     */  
    public static XMLGregorianCalendar dateToXmlDate(Date date){  
            Calendar cal = Calendar.getInstance();  
            cal.setTime(date);  
            DatatypeFactory dtf = null;  
             try {  
                dtf = DatatypeFactory.newInstance();  
            } catch (DatatypeConfigurationException e) {  
            }  
            XMLGregorianCalendar dateType = dtf.newXMLGregorianCalendar();  
            dateType.setYear(cal.get(Calendar.YEAR));  
            //由于Calendar.MONTH取值范围为0~11,需要加1  
            dateType.setMonth(cal.get(Calendar.MONTH)+1);  
            dateType.setDay(cal.get(Calendar.DAY_OF_MONTH));  
            dateType.setHour(cal.get(Calendar.HOUR_OF_DAY));  
            dateType.setMinute(cal.get(Calendar.MINUTE));  
            dateType.setSecond(cal.get(Calendar.SECOND));  
            return dateType;  
        }   
  
    /** 
     * 将XMLGregorianCalendar转换为Date 
     * @param cal 
     * @return  
     */  
    public static Date xmlDate2Date(XMLGregorianCalendar cal){  
        return cal.toGregorianCalendar().getTime();  
    }

有关TimeZone的计算

/**
     * Convert the string date value to date value.
     * 
     * @param format
     *            - Time pattern for this date format.
     * @param dateStr
     *            - String date value to be converted.
     * @return Date value for the input date string.
     */
    public static Date getStrToGMTDate(final String format, final String timeZoneOffset, final String dateStr) throws ParseException {
        Date result = null;
        if (!StringUtils.isEmpty(dateStr)) {
            SimpleDateFormat simpleDateFormat = new SimpleDateFormat();
            TimeZone tz=TimeZone.getTimeZone(TIMEZONE_GMT+timeZoneOffset);
            simpleDateFormat.setTimeZone(tz);
            simpleDateFormat.applyPattern(format);
            simpleDateFormat.setLenient(false);
            result = simpleDateFormat.parse(dateStr);
        }
        return result;
    }

    @Test
    public void date1() {

        String departureDateTimeStr = "2017-05-04 10:00";
        LocalDateTime departureDateTime = LocalDateTime.parse(departureDateTimeStr,
                DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm"));

        ZoneOffset offset = ZoneOffset.of("+08:00");
        long hours = Instant.now().until(departureDateTime.toInstant(offset), ChronoUnit.HOURS);
        // Check if the hour difference is more than 24 hours
        if (hours >= 24) {
            System.out.println("----------" + hours);
        }
    }

----------26

参考资料：

http://www.howsoftworks.net/javaapi/java.time/indexlocaldatetime.html

https://docs.oracle.com/javase/8/docs/api/java/time/ZoneOffset.html