Java date validation joda time

Question

Is there anyway to validate if a given date(yyyy-MM-dd) is a valid date? It should handle leap year too. eg(2015-02-29) should be invalid. I\'m retrieving the date as a stri

Answer 1

tl;dr

try {  … java.time.LocalDate.parse( input ) … } 
catch ( java.time.format.DateTimeParseException e ) { … }

java.time

The Joda-Time project is now in maintenance mode, with the team advising migration to the java.time classes.

The LocalDate class represents a date-only value without time-of-day and without time zone.

LocalDate ld = LocalDate.parse( "2015-02-29" ) ;

To detect invalid inputs, trap for a DateTimeParseException.

String input = "2015-02-29";
try
{
    LocalDate ld = LocalDate.parse( input );
    System.out.println( "ld.toString():  " + ld ) ;
} catch ( DateTimeParseException e )
{
    // … handle exception
    System.out.println( e.getLocalizedMessage( ) );
}

Text '2015-02-29' could not be parsed: Invalid date 'February 29' as '2015' is not a leap year

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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.

The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.

To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.

Where to obtain the java.time classes?

• Java SE 8, Java SE 9, and later
  • Built-in.
  • 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
  • Much of the java.time functionality is back-ported to Java 6 & 7 in ThreeTen-Backport.
• Android
  • The ThreeTenABP project adapts ThreeTen-Backport (mentioned above) for Android specifically.
  • 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.

Answer 2

This should work for you, I think (if you want to keep it simple).
You have to do setLenient(false) on a SimpleDateFormat.

public static boolean validateDate(String dateString){
    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
    sdf.setLenient(false);
    try {
        sdf.parse(dateString);
        return true;
    } catch (ParseException ex) {
        return false;
    }
}

Answer 3

Use SimpleDateFormat

public boolean valiDate(String dateString){
    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
    sdf.setLenient(false);
    try {
        Date date = sdf.parse(dateString);
        return true;
    } catch (ParseException ex) {
        return false;
    }
}

Answer 4

The previous responses should be fine, but given that the OP specifically asked for a Joda-Time version, this alternative will also work:

@Test
public void test() {

    String testDateOk = "2015-02-25"; // Normal date, no leap year
    String testDateOk2 = "2016-02-29"; // Edge-case for leap year
    String testDateWrong = "2017-02-29"; // Wrong date in a non-leap year
    String testDateInvalid = "2016-14-29"; // plain wrong date

    assertTrue(isValidDate(testDateOk));
    assertTrue(isValidDate(testDateOk2));
    assertFalse(isValidDate(testDateWrong));
    assertFalse(isValidDate(testDateInvalid));
}

boolean isValidDate(String dateToValidate){
    String pattern = "yyyy-MM-dd";

    try {
        DateTimeFormatter fmt = DateTimeFormat.forPattern(pattern);
        fmt.parseDateTime(dateToValidate);
    } catch (Exception e) {
        return false;
    }
    return true;
}