I have an arraylist:
ArrayList<String> wholeWeekArrayList = new ArrayList<>();
DatabaseHelper(SQLite) is storing the values into the(above) arrayList:
Cursor data = mDatabaseHelper.getData();
while (data.moveToNext() ) {
wholeWeekArrayListString.add(data.getString(1));
//getString(1) is column values from SQLite
}
Then I have SumofWeek where all the data in wholeWeekArrayListString is added together.
(I Convert wholeWeekArrayListString to double to view it in a TEXTVIEW);
I want this SumOfWeek to reset to Zero at the end of the week but the data inside the SQLite must keep adding(for SumOfMonth view).
So by Sunday the data may be $50.00 (for Example) and Starting on int Monday. the data must reset to 0.0 and sum all the way up until Sunday.
This must happen weekly.
How would u do this? I have tried assining days of weeks.
Monday =1;
Tuesday = 2;
Wednesday =3;
// ...
and iterate through the whole week but Im not able to get(i), which is the data of each single day of the week and then reset it on which is
int Sunday =7;
I have the total amount but dont know what method to use to reset the data at the end of the week?
Without changing the DB calls, you´ll have to store the timestamp of the latest reset (resetTimestamp in the example below). If the current time is in a different week, the code will trigger a reset of sumofWeek. After that, it´s your normal sumofWeek logic.
Thread safety: to be added depending on the application specifics.
private ArrayList<Long> sumofWeek = new ArrayList<>();
private Long resetTimestamp;
public void populateWeek() {
if(resetTimestamp == null || isDifferentWeek(resetTimestamp)) {
sumofWeek = new ArrayList<Long>();
for(int i = 0; i < 7; i++){
sumofWeek.add(0l);
}
System.out.println(sumofWeek);
resetTimestamp = java.lang.System.currentTimeMillis();
}
// populate sumofWeek here
}
private boolean isDifferentWeek(long resetTimestamp) {
Calendar cl1 = new GregorianCalendar();
cl1.setTimeInMillis(java.lang.System.currentTimeMillis());
Calendar cl2 = new GregorianCalendar();
cl2.setTimeInMillis(resetTimestamp);
return cl1.get(Calendar.WEEK_OF_YEAR) != cl2.get(Calendar.WEEK_OF_YEAR);
}
Related
i am trying to create an Array of Calendar Objects where i get all dates between start and end, while skipping the date "skip". So let's imagine i have the dates:
start = 04.03.2016
skip = 21.07.2016
end = 02.03.2017
i tried something like this, but it didn't work that well:
public static Calendar[] getRange(Calendar start, Calendar skip, Calendar end){
Calendar[] daysRange = new Calendar[100];
Calendar placeholder = Calendar.getInstance();
while(start.before(end)){
if(placeholder.getTime() == skip.getTime()){
continue;
} placeholder.add(Calendar.Date, 1);
}
//(pseudocode)
//add placeholder to daysRange
return daysRange;
}
I would appreciate any tips on how i could continue.
Thanks!
First:
while (start.before(end)) {
You never modify start or end, so the loop is endless.
Second: you use one placeholder object, that means that your whole array points to that one object, create a new Calendar for every step en the loop.
Third: don't use an array, use an ArrayList.
This question already has answers here:
Java - Check if array contains 3 consecutive dates
(4 answers)
Closed 5 years ago.
I have an array of unique dates from each time the user completes a task. I want to check if the dates within the array are consecutive from and including todays date.
If the array contains dates: "2017/6/2, 2017/6/3, 2017/6/4, 2017/6/5" then based on today's date being 2017/6/5 the function would return 4 as there are 4 consecutive dates from and including today.
If the array contains dates "2017/6/2, 2017/6/3, 2017/6/4" then it would return 0 as the array does not include today's date. Otherwise the count would be broken upon a non consecutive date.
List<Date> dateList = new ArrayList<Date>();
int count = 0;
Date todayDate = new Date();
for (int i=0; i<dateList.size(); i++){
// Check if dates within the array are consecutive from todayDate, if so then increment count by 1.
}
If you're using Java 8, consider using the new java.time API. It's easier, less bugged and less error-prone than the old APIs.
If you're using Java <= 7, you can use the ThreeTen Backport, a great backport for Java 8's new date/time classes. And for Android, there's the ThreeTenABP (more on how to use it here).
Although you can also use JodaTime, it's being discontinued and replaced by the new APIs, do I don't recommend start a new project with joda. Even in joda's website it says: "Note that Joda-Time is considered to be a largely “finished” project. No major enhancements are planned. If using Java SE 8, please migrate to java.time (JSR-310).".
As you want to compare just the date (day/month/year), and not the time (hour/minute/second), the best choice is to use the LocalDate class. For java 8, this class is in java.time package, and in ThreeTen Backport, the package is org.threeten.bp. But the classes and methods names are the same.
The code would be like this:
public int count(List<LocalDate> dateList, LocalDate today) {
if (!dateList.contains(today)) { // today is not in the list, return 0
return 0;
}
int count = 0;
LocalDate prev = dateList.get(0); // get first date from list
for (int i = 1; i < dateList.size(); i++) {
LocalDate next = dateList.get(i);
if (prev.plusDays(1).equals(next)) {
// difference between dates is one day
count++;
} else {
// difference between dates is not 1
// Do what? return 0? throw exception?
}
prev = next;
}
return count + 1; // didn't count the first element, adding 1
}
Testing this method:
List<LocalDate> dateList = new ArrayList<>();
dateList.add(LocalDate.of(2017, 6, 2));
dateList.add(LocalDate.of(2017, 6, 3));
dateList.add(LocalDate.of(2017, 6, 4));
dateList.add(LocalDate.of(2017, 6, 5));
LocalDate today = LocalDate.now();
System.out.println(count(dateList, today)); // 4
Another test (when today is not in the list)
List<LocalDate> dateList = new ArrayList<>();
dateList.add(LocalDate.of(2017, 6, 2));
dateList.add(LocalDate.of(2017, 6, 3));
dateList.add(LocalDate.of(2017, 6, 4));
LocalDate today = LocalDate.now();
System.out.println(count(dateList, today)); // 0
Notes:
As it wasn't specified what to do when the days are not consecutive (return 0 or throw exception), I left this part commented. But it should be straightforward to add this to the code
If you want to convert java.util.Date to LocalDate, you can do as follows (using the code of this answer, full explanation is in this link in case you have any questions):
public LocalDate convert(Date date) {
return date.toInstant().atZone(ZoneId.systemDefault()).toLocalDate();
}
// if your Date has no toInstant method, try this:
public LocalDate convert(Date date) {
return Instant.ofEpochMilli(date.getTime()).atZone(ZoneId.systemDefault()).toLocalDate();
}
I understood that you want to check for consecutive days (so, a 1-day difference between the dates). But if you want to check if the previous date is before the next (no matter how many days), you can change the if (prev.plusDays(1).equals(next)) to if (prev.isBefore(next))
I'm not sure if that's the case, but if you want, you can also parse a String directly to a LocalDate (so you don't need to create lots of Date objects), using a DateTimeFormatter:
DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy/M/d");
LocalDate d = LocalDate.parse("2017/6/2", formatter); // 2017-06-02
There are a lot of ways to write it more clear:
Use new Date API;
Use libraries;
But, in such case, with usage of old Date classes, I would do that in such a way:
public static void main(String[] args) {
long millisInDay = TimeUnit.DAYS.toMillis(1);
List<Date> dates = Arrays.asList(new Date("2017/6/2"), new Date("2017/6/3"), new Date("2017/6/4"), new Date("2017/6/5"));
System.out.println(getSequentialNumber(millisInDay, dates));
}
private static int getSequentialNumber(long millisInDay, List<Date> dates) {
int count = 0;
Date now = setMidnight(Calendar.getInstance().getTime());
for (int i = dates.size() - 1; i >= 0; i--) {
Date date = setMidnight(dates.get(i));
if (date.getTime() == now.getTime()) {
count++;
}
now.setTime(now.getTime() - millisInDay);
}
return count;
}
private static Date setMidnight(Date date) {
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
calendar.set(Calendar.MINUTE, 0);
calendar.set(Calendar.MILLISECOND, 0);
calendar.set(Calendar.HOUR, 0);
calendar.set(Calendar.SECOND, 0);
calendar.set(Calendar.HOUR_OF_DAY, 0);
return calendar.getTime();
}
If I understand the requirement correctly, you have an array of Date objects, ordered by date, and guaranteed not to have two Date objects for the same day, but possibly with gaps between the days. Your goal is to return the length of the maximum sub-array that contains only consecutive days and also includes the current day, or to return 0 if there is no such sub-array. The current day may fall anywhere inside that sub-array, not necessarily at the beginning or end.
It's not clear if you need to support crossing year boundaries, but I'll assume so. I also assume that all the Date objects in the list are for the same time zone which is also the time zone for the device on which you are running. If that's not the case, you should refer to this answer for more information on testing whether two Date objects refer to the same day.
It's fairly simple to do this if you work with Calendar objects instead of Date objects. You don't need any third-party libraries, as both Date and Calendar are parts of the standard Android API. I suggest doing this in two phases: first search for the current date in the array and then scan in both directions for either a gap in the dates or an array boundary. Then just count how far you could go in each direction.
public int getDateSpanCount(List<Date> dateList) {
final int n = dateList.size();
final Calendar today = Calendar.getInstance();
final Calendar other = Calendar.getInstance();
int count = 0;
// First search for today in the date array
int posToday = -1;
for (int i=0; i<n; i++) {
other.setTime(dateList.get(i));
if (areSameDay(today, other)) {
posToday = i;
break;
}
}
// If today is in the list, count the size of the sub-array containing today
if (posToday >= 0) {
count++; // count today, at least
final Calendar probe = Calendar.getInstance();
// scan backwards from position of today's date
for (int prevPos = posToday - 1; prevPos >= 0; prevPos--) {
final Date prev = dateList.get(prevPos);
probe.setTime(prev);
other.add(Calendar.DAY_OF_YEAR, -1);
if (areSameDay(probe, other)) {
count++;
other.setTime(prev);
} else {
break;
}
}
// reset the other time
other.setTime(today.getTime());
// scan forward from position of today's date
for (int nextPos = posToday + 1; nextPos < n; nextPos++) {
final Date next = dateList.get(nextPos);
probe.setTime(next);
other.add(Calendar.DAY_OF_YEAR, 1);
if (areSameDay(probe, other)) {
count++;
other.setTime(next);
} else {
break;
}
}
}
return count;
}
/** Test whether two Calendar objects are set to the same day */
private static boolean areSameDay(Calendar c1, Calendar c2) {
// see discussion above if dates may not all be for the local time zone
return c1.get(Calendar.YEAR) == c2.get(Calendar.YEAR) &&
c1.get(Calendar.DAY_OF_YEAR) == c2.get(Calendar.DAY_OF_YEAR);
}
List of dates are as below (The list can be in any order):
3-Jan to 31-Mar, 2-Apr to 30-Jun, 1-Jul to 30-Sep, 4-Oct to 31-Dec
Current Date is: 19-Feb
Can someone please help me with the logic?
My approach is:
if(the given date should be greater than start date and less than end date){//this gives current quarter}else if(difference of the month of current date from the end date of each object should be less than or equal to 5)
i am hard coding the condition less than 5, which may break if in future the range of date will be of 4 months
Second approach is:
we can sort the list in ascending order and can get the current quarter index by comparing with current date and the next quarter will be of next index. But the complexity will be more.
I tried below code, but it gives only current quarter date. I am not able to get next quarter considering there would be only 3 objects and current date month is feb.
public static List getCurrentQtrOffr(List detail,Date currentDate) throws ParseException{
int currentQuarter = 9999, diff1;
int nextquarter = 9999, diff2;
Detail detail1;
Detail detail2;
Detail detail3 = null;
Detail detail4 = null;
Iterator<Detail> iterator = detail.iterator();
List<Detail> list = new ArrayList<Detail>();
while(iterator.hasNext()){
detail1 = iterator.next();
diff1 = getDiff(currentDate,detail1.startTime());
if(diff1>0){
if(iterator.hasNext()){
detail2 = iterator.next();
}else{
detail2 = null;
}
if(detail2 != null){
diff2 = getDiff(currentDate,detail2.startTime());
if(diff1 < diff2 ){
if(currentQuarter > diff1){
nextquarter = currentQuarter;
currentQuarter = diff1;
//how to assign detail3 before updating it with next minimum value, as if there will be only 3 object and flow comes in this if block then detail4 will be null
detail4=detail3;
detail3=detail1;
}else if(nextquarter > diff1){
nextquarter = diff1;
detail4=detail1;
}
}else{
if(currentQuarter > diff2){
nextquarter = currentQuarter;
currentQuarter = diff2;
detail4=detail3;
detail3=detail1;
}else if(nextquarter > diff2){
nextquarter = diff2;
detail4=detail1;
}
}
}else{
if(currentQuarter > diff1){
nextquarter = currentQuarter;
currentQuarter = diff1;
detail4=detail3;
detail3=detail1;
}else if(nextquarter > diff1){
nextquarter = diff1;
detail4=detail1;
}
}
}else{
System.out.println("skipped "+diff1);
}
}
list.add(detail3);
list.add(detail4);
return list;
}
If the periods are mutually exclusive (not overlapping) the you simply check for the first occurrence where:
The target is equal to or later than the start, and…
The target is before the stop.
This logic follows the Half-Open approach commonly used in date-time work where the beginning is inclusive while the ending is exclusive.
A shorter way of saying "the target is equal to or later than the start" is "not before start". The exclamation mark ! means not in Java syntax.
Boolean periodContainsTarget = ( ! target.isBefore( start ) ) && target.isBefore( stop ) ;
The above logic would be used with LocalDate if you meant date with a year. If you literally meant a month and day without a year, use the MonthDay class. The logic works for both.
Use Period class to represent the span of time between a pair of LocalDate objects. See Tutorial.
You might also find useful the Interval class in the ThreeTen-Extra project that supplements java.time.
I need to count the points of a chart for a duration picked by an user.
My chart is about logs, we need to know how many users are connected for every specified minutes while a specific duration. We don't want to use too many queries, so I work essentially with lists.
Dates are stored in String format as "yyyy-MM-dd HH:mm:ss".
My code works but is really too long to load:
old=ofy().load().type(Log.class).filter("site in",selectedSites).filter("license in",ofy().load().type(License.class).filter("name", name)).filter("date_out >=",datemin).filter("date_out <=",datemax).list();
Duration duration = new Duration(firstIn, lastDateOut); //Duration between two dates choosen by the user
int dimension=(int) ((duration.getStandardMinutes())/divideBy); //Number of abscissa points in the chart
DateTime[] dates=new DateTime[dimension+1]; //Init of the dates
int[] counts=new int[dimension+1]; //Init of the count table (count of logged users at the date
DateTime transfert=firstIn; //First date
for(int i=0;i<=dimension;i++){
counts[i]=0;
dates[i]=transfert.minusSeconds(transfert.getSecondOfMinute());
transfert=transfert.plusMinutes(divideBy);
for(Log log:old){
if((StaticMethods.toDateTime(log.getDate_in()).minusSeconds(StaticMethods.toDateTime(log.getDate_in()).getSecondOfMinute()).equals(dates[i]))
||((StaticMethods.toDateTime(log.getDate_in()).minusSeconds(StaticMethods.toDateTime(log.getDate_in()).getSecondOfMinute()).isBefore(dates[i]))
&&(StaticMethods.toDateTime(log.getDate_out()).minusSeconds(StaticMethods.toDateTime(log.getDate_out()).getSecondOfMinute()).isAfter(dates[i])))
||(StaticMethods.toDateTime(log.getDate_out()).minusSeconds(StaticMethods.toDateTime(log.getDate_out()).getSecondOfMinute()).equals(dates[i]))
){
counts[i]++;
}
}
GraphData nw=new GraphData(dates[i].toDate(), counts[i]);
}
I want to know if there is a possible less loading time (have read this and I need to know if there's similar way for approximate values).
you should order your data by Date_out value first, in ascending order. Also you don't need tables for Dates and Counts, try the following instead
Duration duration = new Duration(firstIn, lastDateOut); //Duration between two dates choosen by the user
int dimension=(int) ((duration.getStandardMinutes())/divideBy); //Number of abscissa points in the chart
DateTime transfert=firstIn; //First date
DateTime currentDate=transfert; // X-Axis Date
int currentCount=0; // Y-Axis LoggedUser Count
//Log data
DateTime log_DateIn;
DateTime log_DateOut;
for(int i=0;i<=dimension;i++)
{
currentDate = transfert;
currentCount = 0;
transfert = transfert.plusMinutes(divideBy);
for(Log log:old)
{
// We store our dates into variables, that way we avoid doing the time conversion twice
log_DateIn = StaticMethods.toDateTime(log.getDate_in()).minusSeconds(StaticMethods.toDateTime(log.getDate_in()).getSecondOfMinute());
log_DateOut = StaticMethods.toDateTime(log.getDate_out()).minusSeconds(StaticMethods.toDateTime(log.getDate_out()).getSecondOfMinute());
// Since we made the list ordered by DateOut, we are sure that if the stored DateOut is greater than transfert we can't find another user, that way we can break the for without parsing each log
if(log_DateOut.isAfter(transfert))
break;
// Now we can do checks to see if we need to increase the count
// We just check if the DateIn is between the currentDate and currentDate + divideBy (transfert)
if(log_DateIn.isAfter(currentDate) && log_DateIn.isBefore(transfert))
currentCount++;
// Same thing for DateOut
else if(log_DateOut.isAfter(currentDate) && log_DateOut.isBefore(transfert))
currentCount++;
// Now we need both cases
else if(log_DateIn.isBefore(currentDate) && log_DateOut.isAfter(transfert))
currentCount++;
// Equalities
else if(log_DateIn.equals(currentDate) || log_DateIn.equals(transfert) || log_DateOut.equals(currentDate) || log_DateOut.equals(transfert))
currentCount++;
}
GraphData nw = new GraphData(currentDate, currentCount);
}
Problem: I have a list containg hours, for example:
08:15:00
08:45:00
09:00:00
12:00:00
...
application is allowing user to make an appointment for a specific hour let'say: 8:15:00, each meeting takes half an hour.
Question: How to determine if there is a slot needed for appointment like this? I know that Calendar class have methods before() nad after(), but it doesn'solve my problem. I mean if there is appointment at 12:00 and another one at 12:00, how to prevent before making another one at 12:15?
edit:
I've tried using methods I mentioned before, like:
Calendar cal1 = Calendar.getInstance(); // for example 12:00:00
Calendar cal2 = Calendar.getInstance(); // for exmaple 12:30:00
Calendar userTime = Calendar.getInstance(); // time to test: 12:15:00
if(user.after(cal1)&& user.before(cal2)){
... // do sth
}
Check if the date to check is between the two provided:
SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy hh:mm");
Date before = sdf.parse("07/05/2012 08:00");
Date after = sdf.parse("07/05/2012 08:30");
Date toCheck = sdf.parse("07/05/2012 08:15");
//is toCheck between the two?
boolean isAvailable = (before.getTime() < toCheck.getTime()) && after.getTime() > toCheck.getTime();
To book for a determinate hour, I would do a class with two dates and a method to check this:
public class Appointment{
private Date start;
private Date end;
public boolean isBetween(Date toCheck){....}
}
Then you can simply do an Schedule class extending ArrayList, adding a method isDateAvailable(Date toCheck), iterating the list of Appointments and checking that there is no one conflicting.
I'd have some kind of appointment class with either a start timestamp and a duration or a start time and an end time. Then when adding new appointments to the schedule, check that the appointment with the start time before the new appointment doesn't run over the start time of the proposed new appointment.
Well how you would do it specifically depends on how you are storing your data, format, etc., but generally what you would do is simply check if there is an appointment for any time between the requested time to the requested time + requested length.
// Example (using int time(1 = 1 minute), assuming that appointments can only be at 15min intervals)
boolean isHalfHourTimeSlotAvaliable(int time) {
for (int i = 0; i < appointments.size(); i++) {
if (appointments.get(i).time == time || appointments.get(i).time == time + 15) {
return false;
}
}
return true;
}