DoubleBuffer hasArray() method in Java with Examples
Last Updated :
04 Dec, 2018
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The hasArray() method of java.nio.DoubleBuffer class is used to ensure whether or not the given buffer is backed by an accessible float array. It returns true if there is an accessible backing array to this buffer, else it returns false. If this method returns true, then the array() and arrayOffset() methods may safely be invoked, as they work on the backing array.
Syntax:
Java
Java
public final boolean hasArray()Returns: This method will return true if, and only if, this buffer is backed by an array and is not read-only. Else it returns false. Below are the examples to illustrate the hasArray() method: Examples 1: When the buffer is backed by an array
// Java program to demonstrate
// hasArray() method
import java.nio.*;
import java.util.*;
public class GFG {
public static void main(String[] args)
{
// Declaring the capacity of the DoubleBuffer
int capacity = 10;
// Creating the DoubleBuffer
try {
// creating object of Doublebuffer
// and allocating size capacity
DoubleBuffer fb = DoubleBuffer.allocate(capacity);
// putting the value in Doublebuffer
fb.put(8.56F);
fb.put(2, 9.61F);
fb.rewind();
// checking DoubleBuffer fb is backed by array or not
boolean isArray = fb.hasArray();
// checking if else condition
if (isArray)
System.out.println("DoubleBuffer fb is"
+ " backed by array");
else
System.out.println("DoubleBuffer fb is"
+ " not backed by any array");
}
catch (IllegalArgumentException e) {
System.out.println("IllegalArgumentException catched");
}
catch (ReadOnlyBufferException e) {
System.out.println("ReadOnlyBufferException catched");
}
}
}
// Java program to demonstrate// hasArray() methodimport java.nio.*;import java.util.*;public class GFG { public static void main(String[] args) { // Declaring the capacity of the DoubleBuffer int capacity = 10; // Creating the DoubleBuffer try { // creating object of Doublebuffer // and allocating size capacity DoubleBuffer fb = DoubleBuffer.allocate(capacity); // putting the value in Doublebuffer fb.put(8.56F); fb.put(2, 9.61F); fb.rewind(); // checking DoubleBuffer fb is backed by array or not boolean isArray = fb.hasArray(); // checking if else condition if (isArray) System.out.println("DoubleBuffer fb is" + " backed by array"); else System.out.println("DoubleBuffer fb is" + " not backed by any array"); } catch (IllegalArgumentException e) { System.out.println("IllegalArgumentException catched"); } catch (ReadOnlyBufferException e) { System.out.println("ReadOnlyBufferException catched"); } }}
Output:
Examples 2: When the buffer is backed by an array
DoubleBuffer fb is backed by array
// Java program to demonstrate
// hasArray() method
import java.nio.*;
import java.util.*;
public class GFG {
public static void main(String[] args)
{
// Declaring the capacity of the DoubleBuffer
int capacity = 10;
// Creating the DoubleBuffer
try {
// creating object of Doublebuffer
// and allocating size capacity
DoubleBuffer fb = DoubleBuffer.allocate(capacity);
// putting the value in Doublebuffer
fb.put(8.56F);
fb.put(2, 9.61F);
fb.rewind();
// Creating a read-only copy of DoubleBuffer
// using asReadOnlyBuffer() method
DoubleBuffer fb1 = fb.asReadOnlyBuffer();
// checking DoubleBuffer fb is backed by array or not
boolean isArray = fb1.hasArray();
// checking if else condition
if (isArray)
System.out.println("DoubleBuffer fb is"
+ " backed by array");
else
System.out.println("DoubleBuffer fb is"
+ " not backed by any array");
}
catch (IllegalArgumentException e) {
System.out.println("IllegalArgumentException catched");
}
catch (ReadOnlyBufferException e) {
System.out.println("ReadOnlyBufferException catched");
}
}
}
// Java program to demonstrate// hasArray() methodimport java.nio.*;import java.util.*;public class GFG { public static void main(String[] args) { // Declaring the capacity of the DoubleBuffer int capacity = 10; // Creating the DoubleBuffer try { // creating object of Doublebuffer // and allocating size capacity DoubleBuffer fb = DoubleBuffer.allocate(capacity); // putting the value in Doublebuffer fb.put(8.56F); fb.put(2, 9.61F); fb.rewind(); // Creating a read-only copy of DoubleBuffer // using asReadOnlyBuffer() method DoubleBuffer fb1 = fb.asReadOnlyBuffer(); // checking DoubleBuffer fb is backed by array or not boolean isArray = fb1.hasArray(); // checking if else condition if (isArray) System.out.println("DoubleBuffer fb is" + " backed by array"); else System.out.println("DoubleBuffer fb is" + " not backed by any array"); } catch (IllegalArgumentException e) { System.out.println("IllegalArgumentException catched"); } catch (ReadOnlyBufferException e) { System.out.println("ReadOnlyBufferException catched"); } }}
Output:
DoubleBuffer fb is not backed by any array
