What is the DoubleBuffer arrayOffset() method in Java?

java.nio.DoubleBuffer is a class that is used to store a buffer of doubles. The arrayOffset() method of the class java.nio.DoubleBuffer is used to return the offset of the first element of the buffer inside the buffer’s backing array.

Declaration

The DoubleBuffer.arrayOffset() method is declared as follows:

buff.arrayOffset()

buff: The DoubleBuffer whose first element offset is required.

Return value

The DoubleBuffer.arrayOffest() method returns an int that is the offset of the first element of buff.

Note:

If the buffer is not backed by an accessible array, UnsupportedOperationException is thrown.

If the buffer is backed by an array but the array is read-only, ReadOnlyBufferException is thrown.

Examples

Example 1

Consider the code snippet below, which demonstrates the use of the DoubleBuffer.arrayOffset() method.

import java.nio.*;
import java.util.*;
public class main {
   public static void main(String[] args) {
      int n1 = 5;
      try {
         DoubleBuffer buff1 = DoubleBuffer.allocate(n1);
         buff1.put(1.2);
         buff1.put(4.9);
         System.out.println("buff1: " + Arrays.toString(buff1.array()));
         
         int foo = buff1.arrayOffset();
         System.out.println("\nbuff1 array offset: " + foo);
         
      } catch (IllegalArgumentException e) {
         System.out.println("Error!!! IllegalArgumentException");
      } catch (ReadOnlyBufferException e) {
         System.out.println("Error!!! ReadOnlyBufferException");
      } catch (UnsupportedOperationException e) {
         System.out.println("Error!!! UnsupportedOperationException");
      }
   }
}

import java.nio.*;
import java.util.*;
public class main {
   public static void main(String[] args) {
      int n1 = 5;
      try {
         DoubleBuffer buff1 = DoubleBuffer.allocate(n1);
         buff1.put(1.2);
         buff1.put(4.9);
         System.out.println("buff1: " + Arrays.toString(buff1.array()));
         
         DoubleBuffer buff2 = buff1.asReadOnlyBuffer();
         
         int foo = buff2.arrayOffset();
         System.out.println("\nbuff2 array offset: " + foo);
         
      } catch (IllegalArgumentException e) {
         System.out.println("Error!!! IllegalArgumentException");
      } catch (ReadOnlyBufferException e) {
         System.out.println("Error!!! ReadOnlyBufferException");
      } catch (UnsupportedOperationException e) {
         System.out.println("Error!!! UnsupportedOperationException");
      }
   }
}