Develop Reference

Android GreenDao - How to compare to two date strings?

I have few string properties with custom type java.util.Date added in MainGenerator class.
In querybuilder how can I compare these strings with ge or le or gt or lt.
I save the db values in string type and I compare them like this
qb.queryBuilder().where(TestDao.Properties.Date_entered.ge(start)).list();
It doesn't work.

If you are using greenDao then in your MainGenerator you must be having the date as
testdao.addDateProperty("date_entered").notNull();
So in qb.queryBuilder().where(TestDao.Properties.Date_entered.ge(start)).list();
start should be java.util.Date.

Dates are persisted as timestamps of type long. Thus, for your query parameters, you should also use long values.

First Parse your date in String as you are saving date in database in string format. Then query data. Here is sample code.
SimpleDateFormat dateFormat;
Calendar calendar = Calendar.getInstance();
//Modify Calendar here according to your requirement.
dateFormat=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss", Locale.getDefault());
//Check if you have different date format then replace in above line.
String dateString = dateFormat.format(calendar.getTime());
//Then query your data
qb.queryBuilder().where(TestDao.Properties.Date_entered.ge(dateString )).list();

You can convert String date into milliseconds and can compare the values for your result:
public boolean checkDates(String date1, String date2) {
long milliDate1 = getMilliFromDate(date1);
long milliDate2 = getMilliFromDate(date2);
//Check date according to your requirement and condition
return milliDate1 < milliDate2;
}
public long getMilliFromDate(String dateFormat) {
Date date = new Date();
// "dd/MM/yyyy" this is date format i use you can use your own
//format which you are storing in local database like time stamp "yyyy-MM-dd HH:mm:ss"
SimpleDateFormat formatter = new SimpleDateFormat("dd/MM/yyyy");
try {
date = formatter.parse(dateFormat);
} catch (ParseException e) {
e.printStackTrace();
}
return date.getTime();
}

Convert the time stamps into long value

I would like to convert this time stamps to Long value.
2016-07-13T21:11:45+00:00
I still don't know what the format of above time stamp, like MM/dd/yyyy hh:mm:ss aa to use with the SimpleDateFormat.

Try this code to
String timeStr = "2016-11-01T09:45:00.000+02:00";
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss");
Date dateObj= sdf.parse(timeStr);
System.out.println(dateObj.getTime());

It would be yyyy-MM-dd\'T\'HH:mm:ss and you can convert it to long by:
public static long convertDateToMilliseconds(String fromFormat, String sourceDate) {
SimpleDateFormat sdfFrom = new SimpleDateFormat(fromFormat);
//SimpleDateFormat sdfTo = new SimpleDateFormat(toFormat);
Date date = sdfFrom.parse(sourceDate);
//String convertedDate = sdfTo.format(date);
return date.getTime();
}

Use this link to find in which formate to create Simple date formater then create date object with that date formater. Then you can get time in millis like below
long millisecond = beginupd.getTime();

SimpleDateFormat almost states this in its examples. For that you can use
"yyyy-MM-dd'T'HH:mm:ssXXX"

android date picker set time

i would like to set the date format of my date picker like this:
yyyy-MM-dd HH:ss:mm
I hope this is the correct format for dates in databases. if not, please tell me which format is right.
also i would like to set the hour,minute and second of selected date like 0
Example:
2015-11-30 00:00:00
For this i use this code:
long dateTime = DatePicker.getCalendarView().getDate();
Date date = new Date(dateTime);
date.setHours(0);
date.setMinutes(0);
date.setSeconds(0);
Android Studio tells me, that setHours,setMinutes and setSeconds is deprecated. what is the new way to set this values?

Use Calendar Object instead of Date:
Calendar c = Calendar.getInstance();
c.setTimeInMillis(DatePicker.getCalendarView().getDate(););
c.set(Calendar.HOUR,00);
like wise

SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSSSS'Z'");
String dateString = "2015-11-30 00:00:00";
try {
Date date = df.parse(dateString);
df.applyPattern("yyyy-mm-dd hh:mm:ss");
String result = df.format(date);
}
catch (ParseException e){
e.printStackTrace();
}

Comparison of Date and Time

I have to get count of days which are past to the current day.I have list of days in arraylist.I got the list and I dont know how to compare?Can anyone help me?
This is the code I tried,
private void weeklylogeval(){
int i;
DateFormat dateFormatter = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
dateFormatter.setLenient(false);
Date today = new Date();
String s = dateFormatter.format(today);
System.out.println("current date & time new:::"+s);
for(i=0;i<datetime.size();i++){
String daytime=datetime.get(i);
if(today.before(daytime))
}
}
Pls some one help me!

Try this code for date difference manipulation.
String fd=from_date;//date get from mysql database as string.
String td=to_date;//Today's date as string.
if(!fd.equalsIgnoreCase("") && !td.equalsIgnoreCase("")){
SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy");
SimpleDateFormat formatter;
Date frmdt=new Date(fd);
formatter = new SimpleDateFormat("dd/MM/yyyy");
String s1 = formatter.format(frmdt);
Date todt=new Date(td);
String s2 = formatter.format(todt);
Date frmdate = sdf.parse(s1);
Date todate = sdf.parse(s2);
if(frmdate.compareTo(todate)<=0) {
//do your stuff
} else {
// do your stuff
}
}

http://developer.android.com/reference/java/util/Calendar.html
This should be allot easier to use for your purpose
Edit:
Methods you can use:
boolean after(Object calendar)
Returns whether the Date represented by this Calendar instance is after the Date represented by the parameter.
boolean before(Object calendar)
Returns whether the Date represented by this Calendar instance is before the Date represented by the parameter.

Maybe you can construct a Date form the String you get from DB, and then use today.before(daytime) to compare them.
Date daytime = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss").parse(datetime.get(i));

Comparing formatted dates

I create a date and then format is like this:
Example 1:
SimpleDateFormat sdf = new SimpleDateFormat("HH:mm:ss dd/MM/yyyy");
String currentDate = sdf.format(new Date());
What I would like to do is check if this date is before another date (also formatted the same way). How would I go about doing this?
Example 2:
Also, how would I check whether one of these is before another:
long setForLong = System.currentTimeMillis() + (totalTime*1000);
String display = (String) DateFormat.format("HH:mm:ss dd/MM/yyyy", setForLong);
EDIT:
I think more detail is needed. I create a date in two different ways for two different uses. The first use just formats the current date into a string so it is readable for the user. In the second case, I am using a date in the future with System.currentTimeMillis and adding on a long. Both result in a string.
Both methods format the date in exactly the same way, and I set the strings into a TextView. Later, I need to compare these dates. I do not have the original data/date/etc, only these strings. Becasue they are formatted in the same way, I though it would be easy to compare them.
I have tried the if(String1.compareTo(String2) >0 ) method, but that does not work if the day is changed.

If you only have two String objects that are dates available to you. You will need to process them in something, either in your own comparator class or in another object. In this case, since these are already formatted into dates, you can just create Date objects and compare using the methods previously posted. Something like this:
String string = "05:30:33 15/02/1985";
Date date1 = new SimpleDateFormat("HH:mm:ss dd/MM/yyyy", Locale.ENGLISH).parse(string);
String string2 = "15:30:33 01/02/1985";
Date date2 = new SimpleDateFormat("HH:mm:ss dd/MM/yyyy", Locale.ENGLISH).parse(string2);
if(date1.getTime()>date2.getTime()) {
//date1 greater than date2
}
else if(date1.getTime()<date2.getTime()) {
//date1 less than date2
}
else {
//date1 equal to date2
}

You should use Calendar for convenient comparing dates.
Calendar c1 = Calendar.getInstance();
c1.setTime(Date someDate);
Calendar c2 = Calendar.getInstance();
c2.setTime(Date anotherDate);
if(c1.before(c2)){
// do something
}
And you can format it at any time
SimpleDateFormat sdf = new SimpleDateFormat("HH:mm:ss dd/MM/yyyy");
String currentDate = sdf.format(c1.getTime());