I have a code of which is used to create a 24 hour countdown.
This code checks if a "date" file exists and if it doesn't it creates one, which contains the date and time in 24 hourse/a day. It then gets the current time and compares the two, to create a countdown from the current date, to the date in the document.
This makes it possible to save the timer and check how far it has come even though the code is "turned off". The only issue is the fact that sometimes the timer turns negative. Like if I run the code from the start with no "date" file created on Monday, right before midnight, lets say Monday at half past eleven at night. Then if I stop the code and run it again when the current date has passed midnight, so it is actually Tuesday, but there is still missing up to 23 hours before it hits the actual goal timer. If this is the case, the time left in the countdown is negative. Like it would show "-1day 23hours 60minutes and 60seconds remaining". But if as an example it is run from scratch past midnight on Tuesday and then relaunch after 30 minutes the same day, there is no issue.
I hope you can understand what the issue is, it is slightly hard to express through text. But I have attached the whole code of mine, which is the exact one I am using and of which is having that issue. The code has comments for every actions happening, so it should be rather easy to understand.
static File dFileD = new File("date.txt");
static String date = "";
public static void main(String[] args) throws ParseException {
Timer tickTock = new Timer();
TimerTask tickTockTask = new TimerTask(){
public void run(){
try {
timFunRun(); //Timer calls method to start the countdown
} catch (ParseException e) {
e.printStackTrace();
}
}
};
tickTock.schedule(tickTockTask, 1000, 1000);
}
static void timFunRun() throws ParseException {
if (!dFileD.exists()){ //if it doesn't exist, first part
//Get current date and time
Calendar startDat = Calendar.getInstance();
System.out.println("Current date: " + startDat.getTime());
//Get that current date and time and then add 1 day
Calendar todAdd = Calendar.getInstance();
todAdd.add(Calendar.DATE, 1);
System.out.println("Date in 1 day: " + todAdd.getTime());
//Create a format for sending date to text file
SimpleDateFormat formDat = new SimpleDateFormat("EEE, d MMM yyyy HH:mm:ss Z");
String formatted = formDat.format(todAdd.getTime());
System.out.println("Formatted: " + formatted);
try{
PrintWriter dW = new PrintWriter("date.txt");
dW.println(formatted);
dW.close();
} catch (IOException e) {
}
System.out.println(formDat.parse(formatted));
} else { //if it does exist, second part
//Get current date and time
Calendar currentDeT = Calendar.getInstance();
System.out.println("Current date: " + currentDeT.getTime());
SimpleDateFormat formDat2 = new SimpleDateFormat("EEE, d MMM yyyy HH:mm:ss Z");
Date dateFroText = null; //Get the "goal" date
try {
Scanner dateRead = new Scanner(dFileD);
while (dateRead.hasNextLine()) {
date = dateRead.nextLine();
dateFroText = formDat2.parse(date);
System.out.println("Date from text new format: " + dateFroText);
}
dateRead.close();
} catch (Exception e) {
System.out.println("Error!");
}
if (dateFroText != null){ //method to compare the current date and the goal date
Calendar dateFromTxtCal = Calendar.getInstance();
dateFromTxtCal.setTime(dateFroText);
int yearDiff = dateFromTxtCal.get(Calendar.YEAR) - currentDeT.get(Calendar.YEAR);
int dayDiff = ((yearDiff*365) + dateFromTxtCal.get(Calendar.DAY_OF_YEAR)) - currentDeT.get(Calendar.DAY_OF_YEAR);
dayDiff--;
int hourDiffer = dateFromTxtCal.get(Calendar.HOUR_OF_DAY)+23 - currentDeT.get(Calendar.HOUR_OF_DAY);
int minuDiff = dateFromTxtCal.get(Calendar.MINUTE)+60 - currentDeT.get(Calendar.MINUTE);
int secoDiff = dateFromTxtCal.get(Calendar.SECOND)+60 - currentDeT.get(Calendar.SECOND);
System.out.println(dayDiff + " days " + hourDiffer + " hours " + minuDiff +" minutes " + secoDiff + "seconds remaining");
}
}
}
