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–

DoubleBuffer mark() methods in Java with Examples

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