DoubleBuffer reset() methods in Java with Examples

The reset() method of java.nio.DoubleBuffer Class is used to reset the position of this buffer to a position which was previously-marked. In this, neither a marked value is changed nor discarded. It helps to recover the previously marked value in the buffer.

Syntax:

public final DoubleBuffer reset()

Parameters: The method does not take any parameters.

Return Value: This method returns this buffer.

Below are the examples to illustrate the reset() method:

Examples 1:

// Java program to demonstrate
// reset() method

import java.nio.*;
import java.util.*;

public class GFG {

    public static void main(String[] args)
    {

        try {

            double[] darr = { 10.5, 20.5, 30.5, 40.5 };

            // creating object of DoubleBuffer
            // and allocating size capacity
            DoubleBuffer db = DoubleBuffer.wrap(darr);

            // try to set the position at index 2
            db.position(2);

            // Set this buffer mark position
            // using mark() method
            db.mark();

            // try to set the position at index 4
            db.position(4);

            // display position
            System.out.println("position before reset: "
                               + db.position());

            // try to call reset() to restore
            // to the position we marked
            db.reset();

            // display position
            System.out.println("position after reset: "
                               + db.position());
        }

        catch (InvalidMarkException e) {
            System.out.println("new position is less than "
                               + "the position we"
                               + " marked before ");
            System.out.println("Exception throws: " + e);
        }
    }
}

Output:

position before reset: 4
position after reset: 2

Examples 2:

// Java program to demonstrate
// reset() method

import java.nio.*;
import java.util.*;

public class GFG {

    public static void main(String[] args)
    {

        try {

            double[] darr = { 10.5, 20.5, 30.5, 40.5 };

            // creating object of DoubleBuffer
            // and allocating size capacity
            DoubleBuffer db = DoubleBuffer.wrap(darr);

            // try to set the position at index 2
            db.position(2);

            // Set this buffer mark position
            // using mark() method
            db.mark();

            // try to set the position at index 4
            db.position(1);

            // display position
            System.out.println("position before reset: "
                               + db.position());

            // try to call reset() to restore
            // to the position we marked
            db.reset();

            // display position
            System.out.println("position after reset: "
                               + db.position());
        }

        catch (InvalidMarkException e) {
            System.out.println("\nnew position is less than "
                               + "the position we"
                               + " marked before ");
            System.out.println("Exception throws: " + e);
        }
    }
}

Output:

position before reset: 1

new position is less than the position we marked before 
Exception throws: java.nio.InvalidMarkException

Reference: https://docs.oracle.com/javase/9/docs/api/java/nio/DoubleBuffer.html#order–