Java | Date format validation using Regex

We use java.util.regex.Pattern.compile(String regex) method which compiles the given regular expression into a pattern. Here regex is the expression to be compiled.

Java

// Java program to check if given date is
// valid or not.
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class GeeksforGeeks {

    // Returns true if d is in format
    // /dd/mm/yyyy
    public static boolean isValidDate(String d)
    {
        String regex = "^(1[0-2]|0[1-9])/(3[01]"
                       + "|[12][0-9]|0[1-9])/[0-9]{4}$";
        Pattern pattern = Pattern.compile(regex);
        Matcher matcher = pattern.matcher((CharSequence)d);
        return matcher.matches();
    }

    public static void main(String args[])
    {
        System.out.println(isValidDate("10/12/2016"));
        System.out.println(isValidDate("10/02/18"));
    }
}

Output:

true
false

More ways to validate a date :

SimpleDateFormat class. We can use parse method of this class to validate the date.
Writing our own method to check if a date is valid.

Java | Date format validation using Regex

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