I find it curious that the most obvious way to create Date objects in Java has been deprecated and appears to have been "substituted" with a not so obvious to use lenient calendar.
How do you check that a date, given as a combination of day, month, and year, is a valid date?
For instance, 2008-02-31 (as in yyyy-mm-dd) would be an invalid date.
Key is df.setLenient(false);. This is more than enough for simple cases. If you are looking for a more robust (I doubt that) and/or alternate libraries like joda-time, then look at the answer by user "tardate"
final static String DATE_FORMAT = "dd-MM-yyyy";
public static boolean isDateValid(String date)
{
try {
DateFormat df = new SimpleDateFormat(DATE_FORMAT);
df.setLenient(false);
df.parse(date);
return true;
} catch (ParseException e) {
return false;
}
}
As shown by #Maglob, the basic approach is to test the conversion from string to date using SimpleDateFormat.parse. That will catch invalid day/month combinations like 2008-02-31.
However, in practice that is rarely enough since SimpleDateFormat.parse is exceedingly liberal. There are two behaviours you might be concerned with:
Invalid characters in the date string
Surprisingly, 2008-02-2x will "pass" as a valid date with locale format = "yyyy-MM-dd" for example. Even when isLenient==false.
Years: 2, 3 or 4 digits?
You may also want to enforce 4-digit years rather than allowing the default SimpleDateFormat behaviour (which will interpret "12-02-31" differently depending on whether your format was "yyyy-MM-dd" or "yy-MM-dd")
A Strict Solution with the Standard Library
So a complete string to date test could look like this: a combination of regex match, and then a forced date conversion. The trick with the regex is to make it locale-friendly.
Date parseDate(String maybeDate, String format, boolean lenient) {
Date date = null;
// test date string matches format structure using regex
// - weed out illegal characters and enforce 4-digit year
// - create the regex based on the local format string
String reFormat = Pattern.compile("d+|M+").matcher(Matcher.quoteReplacement(format)).replaceAll("\\\\d{1,2}");
reFormat = Pattern.compile("y+").matcher(reFormat).replaceAll("\\\\d{4}");
if ( Pattern.compile(reFormat).matcher(maybeDate).matches() ) {
// date string matches format structure,
// - now test it can be converted to a valid date
SimpleDateFormat sdf = (SimpleDateFormat)DateFormat.getDateInstance();
sdf.applyPattern(format);
sdf.setLenient(lenient);
try { date = sdf.parse(maybeDate); } catch (ParseException e) { }
}
return date;
}
// used like this:
Date date = parseDate( "21/5/2009", "d/M/yyyy", false);
Note that the regex assumes the format string contains only day, month, year, and separator characters. Aside from that, format can be in any locale format: "d/MM/yy", "yyyy-MM-dd", and so on. The format string for the current locale could be obtained like this:
Locale locale = Locale.getDefault();
SimpleDateFormat sdf = (SimpleDateFormat)DateFormat.getDateInstance(DateFormat.SHORT, locale );
String format = sdf.toPattern();
Joda Time - Better Alternative?
I've been hearing about joda time recently and thought I'd compare. Two points:
Seems better at being strict about invalid characters in the date string, unlike SimpleDateFormat
Can't see a way to enforce 4-digit years with it yet (but I guess you could create your own DateTimeFormatter for this purpose)
It's quite simple to use:
import org.joda.time.format.*;
import org.joda.time.DateTime;
org.joda.time.DateTime parseDate(String maybeDate, String format) {
org.joda.time.DateTime date = null;
try {
DateTimeFormatter fmt = DateTimeFormat.forPattern(format);
date = fmt.parseDateTime(maybeDate);
} catch (Exception e) { }
return date;
}
tl;dr
Use the strict mode on java.time.DateTimeFormatter to parse a LocalDate. Trap for the DateTimeParseException.
LocalDate.parse( // Represent a date-only value, without time-of-day and without time zone.
"31/02/2000" , // Input string.
DateTimeFormatter // Define a formatting pattern to match your input string.
.ofPattern ( "dd/MM/uuuu" )
.withResolverStyle ( ResolverStyle.STRICT ) // Specify leniency in tolerating questionable inputs.
)
After parsing, you might check for reasonable value. For example, a birth date within last one hundred years.
birthDate.isAfter( LocalDate.now().minusYears( 100 ) )
Avoid legacy date-time classes
Avoid using the troublesome old date-time classes shipped with the earliest versions of Java. Now supplanted by the java.time classes.
LocalDate & DateTimeFormatter & ResolverStyle
The LocalDate class represents a date-only value without time-of-day and without time zone.
String input = "31/02/2000";
DateTimeFormatter f = DateTimeFormatter.ofPattern ( "dd/MM/uuuu" );
try {
LocalDate ld = LocalDate.parse ( input , f );
System.out.println ( "ld: " + ld );
} catch ( DateTimeParseException e ) {
System.out.println ( "ERROR: " + e );
}
The java.time.DateTimeFormatter class can be set to parse strings with any of three leniency modes defined in the ResolverStyle enum. We insert a line into the above code to try each of the modes.
f = f.withResolverStyle ( ResolverStyle.LENIENT );
The results:
ResolverStyle.LENIENTld: 2000-03-02
ResolverStyle.SMARTld: 2000-02-29
ResolverStyle.STRICTERROR: java.time.format.DateTimeParseException: Text '31/02/2000' could not be parsed: Invalid date 'FEBRUARY 31'
We can see that in ResolverStyle.LENIENT mode, the invalid date is moved forward an equivalent number of days. In ResolverStyle.SMART mode (the default), a logical decision is made to keep the date within the month and going with the last possible day of the month, Feb 29 in a leap year, as there is no 31st day in that month. The ResolverStyle.STRICT mode throws an exception complaining that there is no such date.
All three of these are reasonable depending on your business problem and policies. Sounds like in your case you want the strict mode to reject the invalid date rather than adjust it.
About java.time
The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.
To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.
The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.
You may exchange java.time objects directly with your database. Use a JDBC driver compliant with JDBC 4.2 or later. No need for strings, no need for java.sql.* classes.
Where to obtain the java.time classes?
Java SE 8, Java SE 9, Java SE 10, Java SE 11, and later - Part of the standard Java API with a bundled implementation.
Java 9 adds some minor features and fixes.
Java SE 6 and Java SE 7
Most of the java.time functionality is back-ported to Java 6 & 7 in ThreeTen-Backport.
Android
Later versions of Android bundle implementations of the java.time classes.
For earlier Android (<26), the ThreeTenABP project adapts ThreeTen-Backport (mentioned above). See How to use ThreeTenABP….
The ThreeTen-Extra project extends java.time with additional classes. This project is a proving ground for possible future additions to java.time. You may find some useful classes here such as Interval, YearWeek, YearQuarter, and more.
You can use SimpleDateFormat
For example something like:
boolean isLegalDate(String s) {
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
sdf.setLenient(false);
return sdf.parse(s, new ParsePosition(0)) != null;
}
The current way is to use the calendar class. It has the setLenient method that will validate the date and throw and exception if it is out of range as in your example.
Forgot to add:
If you get a calendar instance and set the time using your date, this is how you get the validation.
Calendar cal = Calendar.getInstance();
cal.setLenient(false);
cal.setTime(yourDate);
try {
cal.getTime();
}
catch (Exception e) {
System.out.println("Invalid date");
}
java.time
With the Date and Time API (java.time classes) built into Java 8 and later, you can use the LocalDate class.
public static boolean isDateValid(int year, int month, int day) {
try {
LocalDate.of(year, month, day);
} catch (DateTimeException e) {
return false;
}
return true;
}
Building on Aravind's answer to fix the problem pointed out by ceklock in his comment, I added a method to verify that the dateString doesn't contain any invalid character.
Here is how I do:
private boolean isDateCorrect(String dateString) {
try {
Date date = mDateFormatter.parse(dateString);
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
return matchesOurDatePattern(dateString); //added my method
}
catch (ParseException e) {
return false;
}
}
/**
* This will check if the provided string matches our date format
* #param dateString
* #return true if the passed string matches format 2014-1-15 (YYYY-MM-dd)
*/
private boolean matchesDatePattern(String dateString) {
return dateString.matches("^\\d+\\-\\d+\\-\\d+");
}
An alternative strict solution using the standard library is to perform the following:
1) Create a strict SimpleDateFormat using your pattern
2) Attempt to parse the user entered value using the format object
3) If successful, reformat the Date resulting from (2) using the same date format (from (1))
4) Compare the reformatted date against the original, user-entered value. If they're equal then the value entered strictly matches your pattern.
This way, you don't need to create complex regular expressions - in my case I needed to support all of SimpleDateFormat's pattern syntax, rather than be limited to certain types like just days, months and years.
I suggest you to use org.apache.commons.validator.GenericValidator class from apache.
GenericValidator.isDate(String value, String datePattern, boolean strict);
Note: strict - Whether or not to have an exact match of the datePattern.
I think the simpliest is just to convert a string into a date object and convert it back to a string. The given date string is fine if both strings still match.
public boolean isDateValid(String dateString, String pattern)
{
try
{
SimpleDateFormat sdf = new SimpleDateFormat(pattern);
if (sdf.format(sdf.parse(dateString)).equals(dateString))
return true;
}
catch (ParseException pe) {}
return false;
}
Assuming that both of those are Strings (otherwise they'd already be valid Dates), here's one way:
package cruft;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
public class DateValidator
{
private static final DateFormat DEFAULT_FORMATTER;
static
{
DEFAULT_FORMATTER = new SimpleDateFormat("dd-MM-yyyy");
DEFAULT_FORMATTER.setLenient(false);
}
public static void main(String[] args)
{
for (String dateString : args)
{
try
{
System.out.println("arg: " + dateString + " date: " + convertDateString(dateString));
}
catch (ParseException e)
{
System.out.println("could not parse " + dateString);
}
}
}
public static Date convertDateString(String dateString) throws ParseException
{
return DEFAULT_FORMATTER.parse(dateString);
}
}
Here's the output I get:
java cruft.DateValidator 32-11-2010 31-02-2010 04-01-2011
could not parse 32-11-2010
could not parse 31-02-2010
arg: 04-01-2011 date: Tue Jan 04 00:00:00 EST 2011
Process finished with exit code 0
As you can see, it does handle both of your cases nicely.
This is working great for me. Approach suggested above by Ben.
private static boolean isDateValid(String s) {
SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy");
try {
Date d = asDate(s);
if (sdf.format(d).equals(s)) {
return true;
} else {
return false;
}
} catch (ParseException e) {
return false;
}
}
looks like SimpleDateFormat is not checking the pattern strictly even after setLenient(false); method is applied on it, so i have used below method to validate if the date inputted is valid date or not as per supplied pattern.
import java.time.format.DateTimeFormatter;
import java.time.format.DateTimeParseException;
public boolean isValidFormat(String dateString, String pattern) {
boolean valid = true;
DateTimeFormatter formatter = DateTimeFormatter.ofPattern(pattern);
try {
formatter.parse(dateString);
} catch (DateTimeParseException e) {
valid = false;
}
return valid;
}
Two comments on the use of SimpleDateFormat.
it should be declared as a static instance
if declared as static access should be synchronized as it is not thread safe
IME that is better that instantiating an instance for each parse of a date.
Above methods of date parsing are nice , i just added new check in existing methods that double check the converted date with original date using formater, so it works for almost each case as i verified. e.g. 02/29/2013 is invalid date.
Given function parse the date according to current acceptable date formats. It returns true if date is not parsed successfully.
public final boolean validateDateFormat(final String date) {
String[] formatStrings = {"MM/dd/yyyy"};
boolean isInvalidFormat = false;
Date dateObj;
for (String formatString : formatStrings) {
try {
SimpleDateFormat sdf = (SimpleDateFormat) DateFormat.getDateInstance();
sdf.applyPattern(formatString);
sdf.setLenient(false);
dateObj = sdf.parse(date);
System.out.println(dateObj);
if (date.equals(sdf.format(dateObj))) {
isInvalidFormat = false;
break;
}
} catch (ParseException e) {
isInvalidFormat = true;
}
}
return isInvalidFormat;
}
Here's what I did for Node environment using no external libraries:
Date.prototype.yyyymmdd = function() {
var yyyy = this.getFullYear().toString();
var mm = (this.getMonth()+1).toString(); // getMonth() is zero-based
var dd = this.getDate().toString();
return zeroPad([yyyy, mm, dd].join('-'));
};
function zeroPad(date_string) {
var dt = date_string.split('-');
return dt[0] + '-' + (dt[1][1]?dt[1]:"0"+dt[1][0]) + '-' + (dt[2][1]?dt[2]:"0"+dt[2][0]);
}
function isDateCorrect(in_string) {
if (!matchesDatePattern) return false;
in_string = zeroPad(in_string);
try {
var idate = new Date(in_string);
var out_string = idate.yyyymmdd();
return in_string == out_string;
} catch(err) {
return false;
}
function matchesDatePattern(date_string) {
var dateFormat = /[0-9]+-[0-9]+-[0-9]+/;
return dateFormat.test(date_string);
}
}
And here is how to use it:
isDateCorrect('2014-02-23')
true
// to return valid days of month, according to month and year
int returnDaysofMonth(int month, int year) {
int daysInMonth;
boolean leapYear;
leapYear = checkLeap(year);
if (month == 4 || month == 6 || month == 9 || month == 11)
daysInMonth = 30;
else if (month == 2)
daysInMonth = (leapYear) ? 29 : 28;
else
daysInMonth = 31;
return daysInMonth;
}
// to check a year is leap or not
private boolean checkLeap(int year) {
Calendar cal = Calendar.getInstance();
cal.set(Calendar.YEAR, year);
return cal.getActualMaximum(Calendar.DAY_OF_YEAR) > 365;
}
Here is I would check the date format:
public static boolean checkFormat(String dateTimeString) {
return dateTimeString.matches("^\\d{4}-\\d{2}-\\d{2}") || dateTimeString.matches("^\\d{4}-\\d{2}-\\d{2}\\s\\d{2}:\\d{2}:\\d{2}")
|| dateTimeString.matches("^\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}") || dateTimeString
.matches("^\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}Z") ||
dateTimeString.matches("^\\d{4}-\\d{2}-\\d{2}\\s\\d{2}:\\d{2}:\\d{2}Z");
}
public static String detectDateFormat(String inputDate, String requiredFormat) {
String tempDate = inputDate.replace("/", "").replace("-", "").replace(" ", "");
String dateFormat;
if (tempDate.matches("([0-12]{2})([0-31]{2})([0-9]{4})")) {
dateFormat = "MMddyyyy";
} else if (tempDate.matches("([0-31]{2})([0-12]{2})([0-9]{4})")) {
dateFormat = "ddMMyyyy";
} else if (tempDate.matches("([0-9]{4})([0-12]{2})([0-31]{2})")) {
dateFormat = "yyyyMMdd";
} else if (tempDate.matches("([0-9]{4})([0-31]{2})([0-12]{2})")) {
dateFormat = "yyyyddMM";
} else if (tempDate.matches("([0-31]{2})([a-z]{3})([0-9]{4})")) {
dateFormat = "ddMMMyyyy";
} else if (tempDate.matches("([a-z]{3})([0-31]{2})([0-9]{4})")) {
dateFormat = "MMMddyyyy";
} else if (tempDate.matches("([0-9]{4})([a-z]{3})([0-31]{2})")) {
dateFormat = "yyyyMMMdd";
} else if (tempDate.matches("([0-9]{4})([0-31]{2})([a-z]{3})")) {
dateFormat = "yyyyddMMM";
} else {
return "Pattern Not Added";
//add your required regex
}
try {
String formattedDate = new SimpleDateFormat(requiredFormat, Locale.ENGLISH).format(new SimpleDateFormat(dateFormat).parse(tempDate));
return formattedDate;
} catch (Exception e) {
//
return "";
}
}
setLenient to false if you like a strict validation
public boolean isThisDateValid(String dateToValidate, String dateFromat){
if(dateToValidate == null){
return false;
}
SimpleDateFormat sdf = new SimpleDateFormat(dateFromat);
sdf.setLenient(false);
try {
//if not valid, it will throw ParseException
Date date = sdf.parse(dateToValidate);
System.out.println(date);
} catch (ParseException e) {
e.printStackTrace();
return false;
}
return true;
}
With 'legacy' date format, we can format the result and compare it back to the source.
public boolean isValidFormat(String source, String pattern) {
SimpleDateFormat sd = new SimpleDateFormat(pattern);
sd.setLenient(false);
try {
Date date = sd.parse(source);
return date != null && sd.format(date).equals(source);
} catch (Exception e) {
return false;
}
}
This execerpt says 'false' to source=01.01.04 with pattern '01.01.2004'
We can use the org.apache.commons.validator.GenericValidator's method directly without adding the whole library:
public static boolean isValidDate(String value, String datePattern, boolean strict) {
if (value == null
|| datePattern == null
|| datePattern.length() <= 0) {
return false;
}
SimpleDateFormat formatter = new SimpleDateFormat(datePattern, Locale.ENGLISH);
formatter.setLenient(false);
try {
formatter.parse(value);
} catch(ParseException e) {
return false;
}
if (strict && (datePattern.length() != value.length())) {
return false;
}
return true;
}
A simple and elegant way for Android developers (Java 8 not required):
// month value is 1-based. e.g., 1 for January.
public static boolean isDateValid(int year, int month, int day) {
Calendar calendar = Calendar.getInstance();
try {
calendar.setLenient(false);
calendar.set(year, month-1, day);
calendar.getTime();
return true;
} catch (Exception e) {
return false;
}
}
Below code works with dd/MM/yyyy format and can be used to check NotNull,NotEmpty as well.
public static boolean validateJavaDate(String strDate) {
if (strDate != null && !strDate.isEmpty() && !strDate.equalsIgnoreCase(" ")) {
{
SimpleDateFormat date = new SimpleDateFormat("dd/MM/yyyy");
date.setLenient(false);
try {
Date javaDate = date.parse(strDate);
System.out.println(strDate + " Valid Date format");
}
catch (ParseException e) {
System.out.println(strDate + " Invalid Date format");
return false;
}
return true;
}
} else {
System.out.println(strDate + "----> Date is Null/Empty");
return false;
}
}
I didn't found my "bug" in another question, so I really need help.
In my app, I have this code:
Calendar calendar = Calendar.getInstance();
calendar.set(Calendar.MONTH, Calendar.MONTH);
calendar.set(Calendar.YEAR, Calendar.YEAR);
calendar.set(Calendar.DAY_OF_MONTH, Calendar.DAY_OF_MONTH);
calendar.set(Calendar.HOUR_OF_DAY, Calendar.HOUR);
calendar.set(Calendar.MINUTE, Calendar.MINUTE);
calendar.set(Calendar.SECOND, Calendar.SECOND);
frase(calendar);
This code is inside onCreate and the code below is below onCreate();
public void frase(Calendar calendar)
{
int day = calendar.get(Calendar.DAY_OF_WEEK);
switch (day) {
case Calendar.MONDAY:textView.setText(getText(R.string.segunda));break;
case Calendar.TUESDAY:textView.setText(getText(R.string.terca));break;
case Calendar.WEDNESDAY:textView.setText(getText(R.string.quarta));break;
case Calendar.THURSDAY:textView.setText(getText(R.string.quinta));break;
case Calendar.FRIDAY:textView.setText(getText(R.string.sexta));break;
case Calendar.SATURDAY:textView.setText(getText(R.string.sabado));break;
case Calendar.SUNDAY:textView.setText(getText(R.string.domingo));break;
}
}
When I run the app, my emulator always returns me the Saturday case but the emulator day of the week is wednesday.
The second argument to Calendar.set() is the value you want to that particular field defined by the first argument. Now you're setting constant values i.e. field index numbers, which makes no sense.
Remove your set() calls altogether. Calendar.getInstance() already returns an instance that is initialized to current date and time.
Get Date
public static String getDate() {
Date myDate = new Date();
String date = new SimpleDateFormat("yyyy-MM-dd").format(myDate);
// new SimpleDateFormat("hh-mm-a").format(myDate);
return date;
}
Get day of week
public static int dayOfWeek(String date) {
try {
int day = 0;
SimpleDateFormat simpleDateformat = new SimpleDateFormat("yyyy-MM-dd");
Date now = simpleDateformat.parse(date);
Calendar calendar = Calendar.getInstance();
calendar.setTime(now);
day = calendar.get(Calendar.DAY_OF_WEEK) - 1;
return day;
} catch (Exception e) {
return null;
}
}
Or simply call
getDay(new Date());
public static String getDay(Date date){
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("EEEE");
//System.out.println("DAY "+simpleDateFormat.format(date).toUpperCase());
return simpleDateFormat.format(date).toUpperCase();
}
This question already has answers here:
Localized date format in Java
(6 answers)
Closed 8 years ago.
I need to show date and time in this format, Date: 9th Dec, Time: 19:20
Although my following code is working fine in English, have no idea this is correct way in other languages which my application is supporting like Chinese, Thai, etc. Any idea would be appreciated? Thanks
This is my code:
private String getFormattedTime(Calendar calendar)
{
int hour = calendar.get(Calendar.HOUR_OF_DAY);
int minute = calendar.get(Calendar.MINUTE);
StringBuilder sBuilder = new StringBuilder(4);
sBuilder.append(hour);
sBuilder.append(":");
// We want to display the hour like this: 12:09,
// but by not using following code it becomes 12:9
if (minute < 10)
{
sBuilder.append("0");
}
sBuilder.append(minute);
return sBuilder.toString();
}
private String getDateSuffix( int day)
{
if (day < 1 || day > 31)
{
throw new IllegalArgumentException("Illegal day of month");
}
switch (day)
{
case 1:
case 21:
case 31:
return ("st");
case 2:
case 22:
return ("nd");
case 3:
case 23:
return ("rd");
default:
return ("th");
}
}
I would recommend that you use Joda Time.
Here is an example from their Quick Start Guide.
DateTime dt = new DateTime();
String monthName = dt.monthOfYear().getAsText();
String frenchShortName = dt.monthOfYear().getAsShortText(Locale.FRENCH);
While "Dec" could mean December or décembre, Joda will use the correct one, depending on Locale.
Since Locale.CHINESE and Locale.THAI are available, it will do the translation for you.
If you use Java 8, Joda comes with the package.
You will save yourself a mountain of work if you use this package.
I did some research based on what #MadProgrammer said and this is my code for those how have same problem. DateFormat and SimpleDateFormat Examples.
private String getFormattedDate(Calendar calendar)
{
Date date = calendar.getTime(); // out: Dec 9, 2014
// String str = DateFormat.getDateInstance().format(date);
// Log.d(TAG, str);
String str = new SimpleDateFormat("MMM d").format(date);
// Log.d(TAG, str);
return str;
}
private String getFormattedTime(Calendar calendar)
{
Date date = calendar.getTime();
String str = DateFormat.getTimeInstance(DateFormat.SHORT).format(date);
// Log.d(TAG, str);
return str;
}
This question already has answers here:
Get the week start and end date given a current date and week start
(4 answers)
Closed 8 years ago.
I have the date and time stored in preferences as Long:
// put
SharedPreferences settings =
PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
settings.edit().putLong("pref_datetime", System.currentTimeMillis()).commit();
// get
Date date2 = new Date(settings.getLong("pref_datetime", 0));
Once date is extracted, how could I check if it belongs to the current week (starting on Monday) or not?
You can use a Calendar instance to create this Monday and next Monday Date instances based on the current date then check that your date lies between them.
Calendar c = Calendar.getInstance();
c.setFirstDayOfWeek(Calendar.MONDAY);
c.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);
c.set(Calendar.HOUR_OF_DAY, 0);
c.set(Calendar.MINUTE, 0);
c.set(Calendar.SECOND, 0);
c.set(Calendar.MILLISECOND, 0);
Date monday = c.getTime();
Date nextMonday= new Date(monday.getTime()+7*24*60*60*1000);
boolean isThisWeek = date2.after(monday) && date2.before(nextMonday);
You can construct a Calendar, and use getField(int) to get both the Calendar.YEAR and the Calendar.WEEK_OF_YEAR. When those are the same, the two Dates are from the same week.
When constructing the Calendar, also call setFirstDayOfWeek(Calendar.MONDAY) to make sure the weeks start on Monday (if you don't, it depends on the current locale).
After #SiKelly's objection that this won't work reliably in the end of December, beginning of January:
Compare WEEK_OF_YEAR.
If not equal, it is a different week.
If equal, it could be the wrong year, but that is hard to check. So just also check that the difference in getTime() is less than 8 * 24 * 60 * 60 * 1000 (eight days to be on the safe side).
(you could do step 3 first. then you avoid having to construct the calendar at all in many cases).
You can use Calendar to calculate week number for today and your date also,then simpy try to match it,
// put
SharedPreferences settings =
PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
settings.edit().putLong("pref_datetime", System.currentTimeMillis()).commit();
// get
Date date2 = new Date(settings.getLong("pref_datetime", 0));
Calendar calendar = Calendar.getInstance();
calendar.setFirstDayOfWeek(Calendar.MONDAY);
int current_year = calendar.get(Calendar.YEAR);
int current_week_number = calendar.get(Calendar.WEEK_OF_YEAR);
calendar.setTime(date2);
int year = calendar.get(Calendar.YEAR);
int week_number= calendar.get(Calendar.WEEK_OF_YEAR);
if(current_year==year && current_week_number==week_number)
{
//same
}
else
{
//different
}
try this
private boolean is_ThisWeek(Date date2){
Date now =new Date(System.currentTimeMillis());
int diffInDays = (int)( (now.getTime() - date2.getTime())
/ (1000 * 60 * 60 * 24) );
Calendar calendar = Calendar.getInstance();
calendar.setTime(now);
int reslut = calendar.get(Calendar.DAY_OF_WEEK);
int days_before = get_days_before(reslut);
if (diffInDays<days_before) {
Toast.makeText(this, "this week", Toast.LENGTH_SHORT).show();
return true;
}else {
Toast.makeText(this,"not this week", Toast.LENGTH_SHORT).show();
return false;
}
}
int get_days_before(int reslut){
int days_before = 0;
switch (reslut) {
case Calendar.MONDAY:
days_before=1;
break;
case Calendar.TUESDAY:
days_before=2;
break;
case Calendar.WEDNESDAY:
days_before=3;
break;
case Calendar.THURSDAY:
days_before=4;
break;
case Calendar.FRIDAY:
days_before=5;
break;
case Calendar.SATURDAY:
days_before=6;
break;
case Calendar.SUNDAY:
days_before=7;
break;
}
return days_before;
}
i have a table in oracle where I saved the twelve public days in Mexico and I need to calculate a limit day since you registered
public Date calcularFechaLimite() {
try {
DiaFestivoDTO dia = new DiaFestivoDTO();
// Calendar fechaActual = Calendar.getInstance();
Calendar fechaL = Calendar.getInstance();
fechaL.add(Calendar.DATE, 3);
switch (fechaL.get(Calendar.DAY_OF_WEEK)) {
case Calendar.SATURDAY:
fechaL.add(Calendar.DATE, 2);
break;
case Calendar.SUNDAY:
fechaL.add(Calendar.DATE, 2);
break;
case Calendar.MONDAY:
fechaL.add(Calendar.DATE, 2);
break;
case Calendar.TUESDAY:
fechaL.add(Calendar.DATE, 1);
default:
break;
}
dia.setFechaLimite(fechaL.getTime());
Integer numeroDiasFest = seleccionPagoBO.obtenerDiasFestivos(dia);
if (numeroDiasFest != 0) {
fechaL.add(Calendar.DATE, numeroDiasFest);
dia.setFechaLimite(fechaL.getTime());
}
fechaLimite = fechaL.getTime();
} catch (Exception e) {
e.printStackTrace();
}
return fechaLimite;
}
This is what i have but March 28 and 29 are public days and it is not working, any idea??
Several issues:
You are not checking if the first 3 days you skip contain weekend days.
Also you are skipping strange amounts of days and skipping for weekdays as well (which are business days and therefore should not be skipped).
I assume the method DiaFestivoDTO.obtenerDiasFestivos() calculates the number of national holidays in a certain date range but what is the start date? Is it initialized to the current date when DiaFestivoDTO is created?
When there is a national holiday in your date range you increase the date range but never check if this new daterange includes new national holidays or weekend days.
If what you are trying to do is calculate a date '3 business days from now' here's roughly what I would do:
// get all the holidays as java.util.Date
DiaFestivoDTO dia = new DiaFestivoDTO();
List<Date> holidays = dia.getAllNationalHolidays();
// get the current date without the hours, minutes, seconds and millis
Calendar cal = Calendar.getInstance();
cal.set(Calendar.HOUR_OF_DAY, 0);
cal.set(Calendar.MINUTE, 0);
cal.set(Calendar.SECOND, 0);
cal.set(Calendar.MILLISECOND, 0);
// iterate over the dates from now and check if each day is a business day
int businessDayCounter = 0
while (businessDayCounter < 3) {
int dayOfWeek = cal.get(Calendar.DAY_OF_WEEK);
if (dayOfWeek != Calendar.SATURDAY && dayOfWeek != Calendar.SUNDAY && !holidays.contains(cal.getTime())) {
businessDayCounter++;
}
cal.add(Calendar.DAY_OF_YEAR, 1);
}
Date threeBusinessDaysFromNow = cal.getTime();
For this to work I would advise you to add a new method 'getAllNationalHolidays' to list al the holidays because it is more efficient to store twelve dates in memory than to access the database multiple times to check for them.
If you cannot change/add database methods then you could do this
while (businessDayCounter < 3) {
// determine if this day is a holiday
DiaFestivoDTO dia = new DiaFestivoDTO();
dia.setFechaInitial(cal.getTime());
dia.setFechaLimite(cal.getTime());
boolean isHoliday = seleccionPagoBO.obtenerDiasFestivos(dia) > 0;
int dayOfWeek = cal.get(Calendar.DAY_OF_WEEK);
if (dayOfWeek != Calendar.SATURDAY && dayOfWeek != Calendar.SUNDAY && !isHoliday) {
businessDayCounter++;
}
cal.add(Calendar.DAY_OF_YEAR, 1);
}
Here I assumed you can set the 'from' date in your DiaFestivoDTO using 'setFechaInitial' or something like that. But in this way you would be calling the database at least three times which is inefficient.