# **[JAVA] 假日查詢API Calendar型別運用**

###### tags: `Java` `Restful API` `工作筆記`

## [實作目的] 專案需求，需要開一個假日查詢的API，給各個部屬於不同AP的服務call ##

## [前情提要] 後台有假日管理功能，可以手動加入補班日/颱風假/彈性放假

#### DTO ####

package gov.pcc.pwc.service.dto;

public class HolidayApiDTO {
    private String calendarDay;
    private String workingDay;
    private String dateStart;
    private String dateEnd;
    private String date;
    private Integer days;
    private Boolean isWorkingDay;

    public String getCalendarDay() {
        return calendarDay;
    }

    public void setCalendarDay(String calendarDay) {
        this.calendarDay = calendarDay;
    }

    public String getWorkingDay() {
        return workingDay;
    }

    public void setWorkingDay(Boolean workingDay) {
        isWorkingDay = workingDay;
    }

    public void setWorkingDay(String workingDay) {
        this.workingDay = workingDay;
    }

    public String getDateStart() {
        return dateStart;
    }

    public void setDateStart(String dateStart) {
        this.dateStart = dateStart;
    }

    public String getDateEnd() {
        return dateEnd;
    }

    public void setDateEnd(String dateEnd) {
        this.dateEnd = dateEnd;
    }

    public String getDate() {
        return date;
    }

    public void setDate(String date) {
        this.date = date;
    }

    public Integer getDays() {
        return days;
    }

    public void setDays(Integer days) {
        this.days = days;
    }

    public Boolean getIsWorkingDay() {
        return isWorkingDay;
    }

    public void setIsWorkingDay(Boolean isWorkingDay) {
        this.isWorkingDay = isWorkingDay;
    }
}

#### controller類別 ####

package gov.pcc.pwc.pwb.rest;

/**
 * REST controller for managing {@link HolidayApiDTO}.
 */
@RestController
@RequestMapping("/api")
public class HolidayApiResource {

    private final Logger log = LoggerFactory.getLogger(HolidayApiResource.class);

    private static final String ENTITY_NAME = "HolidayApiDAO";

    @Value("${jhipster.clientApp.name}")
    private String applicationName;

    private final AdmHolidayService admHolidayService;
    private final AdmHolidayRepository admHolidayRepository;
    private final HolidayApiService holidayApiService;

    public HolidayApiResource(AdmHolidayService admHolidayService, AdmHolidayRepository admHolidayRepository, HolidayApiService holidayApiService) {
        this.admHolidayService = admHolidayService;
        this.admHolidayRepository = admHolidayRepository;
        this.holidayApiService = holidayApiService;
    }

    @PostMapping("/holiday-api/is-holiday")
    public boolean isHoliday(@Valid @RequestBody HolidayApiDTO holidayApiDTO) throws ParseException {
        log.debug("REST request to get isHoliday : date:{}", holidayApiDTO.getDate());
        return holidayApiService.isHoliday(holidayApiDTO.getDate());
    }

    @PostMapping("/holiday-api/getDate")
    public String getCalendarDayOrWorkingDay(@Valid @RequestBody HolidayApiDTO holidayApiDTO) throws ParseException {
        log.debug("REST request to get calendarDay Or workingDay : date:{}, days:{} ,isWorkingDay:{}", holidayApiDTO.getDate(), holidayApiDTO.getDays(), holidayApiDTO.getIsWorkingDay());
        return holidayApiService.getCalendarDayOrWorkingDay(holidayApiDTO.getDate(), holidayApiDTO.getDays(), holidayApiDTO.getIsWorkingDay());
    }

    @PostMapping("/holiday-api/getDays")
    public HolidayApiDTO getCalendarDayAndWorkingDay(@Valid @RequestBody HolidayApiDTO holidayApiDTO) throws ParseException {
        log.debug("REST request to get calendarDay And workingDay : dateStart:{}, dateEnd:{}", holidayApiDTO.getDateStart(), holidayApiDTO.getDateEnd());
        return holidayApiService.getCalendarDayAndWorkingDay(holidayApiDTO.getDateStart(), holidayApiDTO.getDateEnd());
    }

}

#### service類別 ####

package gov.pcc.pwc.service;

@Service
public class HolidayApiService {

    private final Logger log = LoggerFactory.getLogger(HolidayApiService.class);

    private final AdmHolidayRepository admHolidayRepository;

    public HolidayApiService(AdmHolidayRepository admHolidayRepository) {
        this.admHolidayRepository = admHolidayRepository;
    }

    /**
     * 判斷是否為假日：
     * 輸入111/02/28，於ADM_HOLIDAY找到二二八，回傳true
     * 輸入111/03/05，為星期六，回傳true
     * 輸入111/01/22，為星期六，但在ADM_HOLIDAY找到圍捕般日，回傳false
     * @param date
     * @return boolean
     * @throws ParseException
     */
    public Boolean isHoliday(String date) throws ParseException {
        String addDate = transferMinguoDateToADDate(date);
        Calendar calendarDate = transferADDateStringToCalendar(addDate);
        LocalDate localDate = LocalDate.ofInstant(calendarDate.toInstant(), ZoneId.systemDefault());
        //查詢AMD_HOLIDAY判斷是否是節日、補班日
        if (!admHolidayRepository.existsByHolidayDate(localDate)) {
            //如果不是，繼續判斷是否為星期六、星期日
            switch (calendarDate.get(Calendar.DAY_OF_WEEK)) {
                case Calendar.SATURDAY:
                case Calendar.SUNDAY:
                    return true;
                default:
                    return false;
            }
        } else {
            return true;
        }
    }

    /**
     * 回傳以當日日期開始的工作日or日曆日
     * 輸入111/03/01、5、false，回傳111/03/05
     * 輸入111/03/01、5、true，回傳111/03/07
     * @param date
     * @param days
     * @param isWorkingDay
     * @return
     * @throws ParseException
     */
    public String getCalendarDayOrWorkingDay(String date, Integer days, Boolean isWorkingDay) throws ParseException {
        String adDate = transferMinguoDateToADDate(date);
        Calendar calendarDate = transferADDateStringToCalendar(adDate);
        if (isWorkingDay) {
            try {
                if (isHoliday(transferADDateToMinguoDate(transferCalendarToADDateString(calendarDate)))) {
                    days++;
                }
                for (int i = 0; i < days-1 ; i++) {
                    calendarDate.add(Calendar.DAY_OF_MONTH, 1);
                    if(isHoliday(transferADDateToMinguoDate(transferCalendarToADDateString(calendarDate)))){
                        i--;
                    }
                }
                return transferADDateToMinguoDate(transferCalendarToADDateString(calendarDate));
            } catch (Exception e) {
                log.error(e.getMessage());
            }
        } else {
            calendarDate.add(Calendar.DAY_OF_MONTH, days-1);
            String adDateString = transferCalendarToADDateString(calendarDate);
            String minguoDateString = transferADDateToMinguoDate(adDateString);
            return minguoDateString;
        }
        return null;
    }

    public HolidayApiDTO getCalendarDayAndWorkingDay(String dateStart, String dateEnd) throws ParseException {

        String adDateStart = transferMinguoDateToADDate(dateStart);
        Calendar calendarDateStart = transferADDateStringToCalendar(adDateStart);
        long timeStart = calendarDateStart.getTimeInMillis();
        String adDateEnd = transferMinguoDateToADDate(dateEnd);
        Calendar calendarDateEnd = transferADDateStringToCalendar(adDateEnd);
        long timeEnd = calendarDateEnd.getTimeInMillis();
        int betweenDays = Integer.parseInt(String.valueOf((timeEnd - timeStart) / (1000 * 60 * 60 * 24)));

        //日曆日
        String calendarDays = String.valueOf(betweenDays + 1);

        //工作日
        int workingDaysCount = 0;
        if (!isHoliday(transferADDateToMinguoDate(transferCalendarToADDateString(calendarDateStart)))) {
            workingDaysCount++;
        }
        for (int i = 0; i < betweenDays; i++) {
            calendarDateStart.add(Calendar.DAY_OF_MONTH, 1);
            workingDaysCount++;
            if (isHoliday(transferADDateToMinguoDate(transferCalendarToADDateString(calendarDateStart)))) {
                workingDaysCount--;
            }
        }
        String workingDays = String.valueOf(workingDaysCount);

        HolidayApiDTO holidayApiDTO = new HolidayApiDTO();
        holidayApiDTO.setCalendarDay(calendarDays);
        holidayApiDTO.setWorkingDay(workingDays);
        return holidayApiDTO;
    }

#### 日期Util ####

    /**
     * Transfer AD date to minguo date.
     * 西元年 yyyyMMdd 轉 民國年 yyy/MM/dd
     *
     * @param dateString the String dateString
     * @return the string
     */
    public static String transferADDateToMinguoDate(String dateString) {
        LocalDate localDate = LocalDate.parse(dateString, DateTimeFormatter.ofPattern("yyyyMMdd"));
        return MinguoDate.from(localDate).format(DateTimeFormatter.ofPattern("yyy/MM/dd"));
    }

    /**
     * Transfer minguo date to AD date.
     * 民國年 yyy/MM/dd 轉 西元年 yyyyMMdd
     *
     * @param dateString the String dateString
     * @return the string
     */
    public static String transferMinguoDateToADDate(String dateString) {
        Chronology chrono = MinguoChronology.INSTANCE;
        DateTimeFormatter df = new DateTimeFormatterBuilder().parseLenient()
                .appendPattern("yyy/MM/dd")
                .toFormatter()
                .withChronology(chrono)
                .withDecimalStyle(DecimalStyle.of(Locale.getDefault()));

        ChronoLocalDate chDate = chrono.date(df.parse(dateString));
        return LocalDate.from(chDate).format(DateTimeFormatter.ofPattern("yyyyMMdd"));
    }

    public static Calendar transferADDateStringToCalendar(String dateString) throws ParseException {
        Calendar cal = Calendar.getInstance();
        SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd", Locale.TAIWAN);
        cal.setTime(sdf.parse(dateString));
        return cal;
    }

    public static String transferCalendarToADDateString(Calendar calendar) {
        SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd", Locale.TAIWAN);
        return sdf.format(calendar.getTime());
    }
}