Date before() method in Java with Examples

The before() method of Java Date class tests whether the date is before the specified date or not.

Syntax:

public boolean before(Date when)

Parameters: The function accepts a single parameter when which specifies the date that has to be checked.

Return Value: It returns a Boolean value. It will return true if this date is before the specified date otherwise false.

Exception: The function throws a single exception that is NullPointerException if when is null.

Program below demonstrates the above mentioned function:

// Java code to demonstrate
// before() function of Date class

import java.util.Date;
import java.util.Calendar;
public class GfG {
    // main method
    public static void main(String[] args)
    {

        // creating a Calendar object
        Calendar c = Calendar.getInstance();

        // set Month
        // MONTH starts with 0 i.e. ( 0 - Jan)
        c.set(Calendar.MONTH, 11);

        // set Date
        c.set(Calendar.DATE, 05);

        // set Year
        c.set(Calendar.YEAR, 1996);

        // creating a date object with specified time.
        Date dateOne = c.getTime();

        System.out.println("Date 1: " + dateOne);

        // creating a date of object
        // storing the current date
        Date currentDate = new Date();

        System.out.println("Date 2: " + currentDate);

        System.out.println("Is Date 2 before Date 1: "
                         + currentDate.before(dateOne));
    }
}

Output:

Date 1: Thu Dec 05 08:15:01 UTC 1996
Date 2: Wed Jan 02 08:15:01 UTC 2019
Is Date 2 before Date 1: false

// Java code to demonstrate
// before() function of Date class

import java.util.Date;

public class GfG {
    // main method
    public static void main(String[] args)
    {

        // creating a date of object
        // storing the current date
        Date currentDate = new Date();

        System.out.println("Date 1: " + currentDate);

        // specifiedDate is assigned to null.
        Date specifiedDate = null;

        System.out.println("Date 1: " + specifiedDate);

        System.out.println("On checking these 2 dates: ");

        try {
            // throws NullPointerException
            System.out.println(currentDate
                                   .before(specifiedDate));
        }
        catch (Exception e) {
            System.out.println("Exception: " + e);
        }
    }
}

Output:

Date 1: Wed Jan 02 08:15:06 UTC 2019
Date 1: null
On checking these 2 dates: 
Exception: java.lang.NullPointerException