DoubleBuffer mark() methods in Java with Examples

The mark() method of java.nio.DoubleBuffer Class is used to mark the current position of this DoubleBuffer as the mark of this buffer.
Syntax:
public DoubleBuffer mark()
Return Value: This method returns this DoubleBuffer after setting the buffer’s mark at the current position.
Below are the examples to illustrate the mark() method:
Examples 1:
// Java program to demonstrate// mark() 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 " + "marked before "); System.out.println("Exception throws: " + e); } }} |
Output:
position before reset: 4 position after reset: 2
Examples 2: To demonstrate InvalidMarkException
// Java program to demonstrate// mark() 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 1 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 " + "marked before "); System.out.println("Exception throws: " + e); } }} |
Output:
position before reset: 1 New position is less than the position marked before Exception throws: java.nio.InvalidMarkException
Reference: https://docs.oracle.com/javase/9/docs/api/java/nio/DoubleBuffer.html#mark–



