Calculate date difference between overlapping periods

Question

hello folks,
i am learning my way into more complex problem of java.
i have to calculate the true period lenght for a set of periods.
it is a little complidated to explain the whole business rules on this subject, but on a nutshell:
we have teams that are give a single day payment for staying in a hotel, but since this team is composed of many people (?this is a team); there are days when more then one person stays in a hotel.
we get these details at the end of a business event when all information is entered on our business intelligence system.
for a given hotel stay, the following details are submitted:
start date
end date
number of days in economic accomodation (lower class)
number of days in luxure accomodation (higher class)
if no number of days in any class, or the number is smaller then lower class is assumed to be the one used
another business rule says that for the first night out (away from their home) staff receives an extra night for their transfer (!generous company!)
i have created a class for holding all this information so far - HotelStay.java
since this is a team information for a given business event i receive anything between 0 to 200 hotel stays.
thus my dataset looks like
teamID
hotelStayStartDt
hotelStayEndDt
daysInLowerClass
daysInHigherClass
my objective are:
to be able to calculate the actual number of stays (including any additions for the first day away)
to be able to calculate number of total days - including over laps - these will be paid in a different rate)
number of days in each hotel class - lower and higher
since i am clueless how to go about it, i would really appreciate assistance here.
below is my HotelStay.java
many thanks,
Nic

Answer 1

here is the class that i have created so far
package businessCalculations.awayStays;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
import com.sun.org.apache.xalan.internal.xsltc.trax.SmartTransformerFactoryImpl;
import com.sun.xml.internal.bind.v2.runtime.reflect.Accessor.SetterOnlyReflection;
* @author
public class HotelStay {
     * hotel starting date of stay hotel stays can only start in the past or
     * today as this is not processing future bookings only dates over and above
     * 1990 are considered into this system
    private Date hotelStayStartDt;
     * hotel date end of staying only dates over and above 1990 are considered
     * into this system
    private Date hotelStayEndDt;
     * days for which a person stayed in economic or other lower class
     * accommodation
    private int daysInLowerClass = 0;
     * days for which a person stayed in de-luxe or other higher class
     * accommodation
    private int daysInHigherClass = 0;
     * flags when person was sleeping in another hotel at the beginning of this
     * stay (they went from one hotel to another without going home in betwee
     * if they were they do not receive the added day bonus for transfer
     * (one overnight stay <b>EXTRA</b>) thus if at the beginning of the stay,
     * they were not sleeping in another hotel, they receive an extra night for
     * their transfer
    private boolean isSleepingAwayOverlapping = false;
     * default constructor
     * @param hotelStayStartDt
     * @param hotelStayEndDt
     * @param daysInLowerClass
     * @param daysInHigherClass
    public HotelStay(Date hotelStayStartDt, Date hotelStayEndDt,
         int daysInLowerClass, int daysInHigherClass) {
     boolean outcome = this.addNewHotelStay(hotelStayStartDt, hotelStayEndDt, daysInLowerClass, daysInHigherClass);
     * @param hotelStayStartDt
     * @param hotelStayEndDt
     * @param daysInLowerClass
     * @param daysInHigherClass
     * @return
    public boolean addNewHotelStay(Date hotelStayStartDt, Date hotelStayEndDt, int daysInLowerClass, int daysInHigherClass) {
     if (this.isValidStayDt(hotelStayStartDt) && this.isValidStayDt(hotelStayEndDt)){
         int lengthOfStay = this.getLengthOfStay(hotelStayStartDt, hotelStayEndDt);
         if(lengthOfStay >=1) {
         this.setHotelStayStartDt(hotelStayStartDt);
         this.setHotelStayEndDt(hotelStayEndDt);
         if (
              (daysInHigherClass + daysInLowerClass == 0)
          ||  (daysInHigherClass + daysInLowerClass <= lengthOfStay + 1 )
          this.setDaysInLowerClass(daysInLowerClass);
          this.setDaysInHigherClass(daysInHigherClass);
         } else {
          this.setDaysInLowerClass(daysInLowerClass);
          this.setDaysInHigherClass(daysInHigherClass);
         return true;
     }else{
         return false;
     * @return the admissionDt
    private Date getHotelStayStartDt() {
     return this.hotelStayStartDt;
     * @param admissionDt
     *            the admissionDt to set
    private void setHotelStayStartDt(Date admissionDt) {
     this.hotelStayStartDt = admissionDt;
     * @return the dischargeDt
    private Date getHotelStayEndDt() {
     return this.hotelStayEndDt;
     * @param dischargeDt
     *            the dischargeDt to set
    private void setHotelStayEndDt(Date dischargeDt) {
     this.hotelStayEndDt = dischargeDt;
     * @return the isOverlappingOtherCcStays
    private boolean isOverlappingOtherCcStays() {
     return this.isSleepingAwayOverlapping;
     * @param isOverlappingOtherCcStays
     *            the isOverlappingOtherCcStays to set
    private void setOverlappingOtherCcStays(boolean isOverlappingOtherCcStays) {
     this.isSleepingAwayOverlapping = isOverlappingOtherCcStays;
     * @return the daysInLowerClass
    private int getDaysInLowerClass() {
     return this.daysInLowerClass;
     * @param daysInLowerClass
     *            the daysInLowerClass to set
    private void setDaysInLowerClass(int daysInLowerClass) {
     this.daysInLowerClass = daysInLowerClass;
     * @return the daysInHigherClass
    private int getDaysInHigherClass() {
     return this.daysInHigherClass;
     * @param daysInHigherClass
     *            the daysInHigherClass to set
    private void setDaysInHigherClass(int daysInHigherClass) {
     this.daysInHigherClass = daysInHigherClass;
     * @return the isSleepingAwayOverlapping
    private boolean isSleepingAwayOverlapping() {
     return this.isSleepingAwayOverlapping;
     * @param isSleepingAwayOverlapping
     *            the isSleepingAwayOverlapping to set
    private void setSleepingAwayOverlapping(boolean isSleepingAwayOverlapping) {
     this.isSleepingAwayOverlapping = isSleepingAwayOverlapping;
    @Override
    public String toString() {
     String rtn = "";
     SimpleDateFormat sdf = new SimpleDateFormat("dd/MMM/yyyy hh:mm");
     String inDt = sdf.format(getHotelStayStartDt());
     String outDt = sdf.format(getHotelStayEndDt());
     rtn = "ArrivalDt("
         + (inDt.isEmpty() ? "" : inDt) + ")\t,BookOutDt("
          + (outDt.isEmpty() ? "" : outDt) + ")\t,DaysInLowerClass ("
          + String.valueOf(getDaysInLowerClass())
          + ")\t,DaysInHigerClass ("
          + String.valueOf(getDaysInHigherClass()) + ")";
     return rtn;
    public int getLengthOfStay(Date hotelStayStartDt, Date hotelStayEndDt ){
     Calendar startDt = new GregorianCalendar();
     startDt.setTime(hotelStayStartDt);
     Calendar endDt = new GregorianCalendar();
     endDt.setTime(hotelStayEndDt);
     long startMill = startDt.getTimeInMillis();
     long endMill = endDt.getTimeInMillis();
     // Calculate difference in days
     // divided by (24 hours, 60 minutes, 60 seconds, 1000 milliseconds
     // casted as (int)
     return (int) ((endMill - startMill) / (24 * 60 * 60 * 1000));
    private boolean isValidStayDt(Date aDate) {
     SimpleDateFormat sdf = new SimpleDateFormat("dd/MMM/yyyy");
     Calendar minDt = new GregorianCalendar();
     Calendar maxDt = new GregorianCalendar();
     maxDt.add(Calendar.DATE, +1);
     try {
         minDt.setTime(sdf.parse("01/jan/1990"));
     } catch (ParseException e) {
         e.printStackTrace();
     if (aDate.after(minDt.getTime()) && aDate.before(maxDt.getTime())) {
         return true;
     } else {
         return false;
}Edited by: www.jegue.net on Jul 17, 2010 11:31 AM