Buffer hasArray() methods in Java with Examples Last Updated : 19 Jan, 2023 Summarize Comments Improve Suggest changes Share Like Article Like Report The hasArray() method of java.nio.Buffer class is used to tell whether or not this buffer is backed by an accessible array. If this method returns true then the array and arrayOffset() methods may safely be invoked. Syntax: public abstract 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 // 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 ByteBuffer int capacity = 10; // Creating the ByteBuffer try { // creating object of bytebuffer // and allocating size capacity ByteBuffer bb = ByteBuffer.allocate(capacity); // putting the value in bytebuffer bb.put((byte)10); bb.put((byte)20); bb.rewind(); // Typecast bytebuffer to Buffer Buffer buffer = (Buffer)bb; // checking buffer is backed by array or not boolean isArray = buffer.hasArray(); // checking if else condition if (isArray) System.out.println("buffer is" + " backed by array"); else System.out.println("buffer is" + " not backed by any array"); } catch (IllegalArgumentException e) { System.out.println("IllegalArgumentException catched"); } catch (ReadOnlyBufferException e) { System.out.println("ReadOnlyBufferException catched"); } } } Output:buffer is backed by array Examples 2: When the buffer is not backed by an array Java // 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 ByteBuffer int capacity = 10; // Creating the ByteBuffer try { // creating object of ByteBuffer // and allocating size capacity ByteBuffer bb = ByteBuffer.allocate(capacity); // putting the value in ByteBuffer bb.put((byte)8.56F); bb.put((byte)10); bb.rewind(); // Creating a read-only copy of ByteBuffer // using asReadOnlyBuffer() method ByteBuffer bb1 = bb.asReadOnlyBuffer(); // Typecast read-only ByteBuffer to read-only buffer Buffer buffer = (Buffer)bb1; // checking buffer is backed by array or not boolean isArray = buffer.hasArray(); // checking if else condition if (isArray) System.out.println("buffer is" + " backed by array"); else System.out.println("buffer is" + " not backed by any array"); } catch (IllegalArgumentException e) { System.out.println("IllegalArgumentException catched"); } catch (ReadOnlyBufferException e) { System.out.println("ReadOnlyBufferException catched"); } } } Output:buffer is not backed by any array Reference: https://docs.oracle.com/javase/9/docs/api/java/nio/Buffer.html#hasArray-- Comment More infoAdvertise with us Next Article Buffer flip() methods in Java with Examples R rohitprasad3 Follow Improve Article Tags : Java Java-Functions Java-NIO package Java-Buffer Practice Tags : Java Similar Reads ByteBuffer hasArray() method in Java with Examples The hasArray() method of java.nio.ByteBuffer class is used to ensure whether or not the given buffer is backed by an accessible byte 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() m 2 min read DoubleBuffer hasArray() method in Java with Examples 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( 2 min read Buffer hasRemaining() methods in Java with Examples The hasRemaining() method of java.nio.Buffer class is used to tell whether there are any elements between the current position and the limit. Syntax: public final boolean hasRemaining() Returns: This method will return true if, and only if, there is at least one element remaining in this buffer. Bel 2 min read Buffer flip() methods in Java with Examples The flip() method of java.nio.ByteBuffer Class is used to flip this buffer. The limit is set to the current position and then the position is set to zero. If the mark is defined then it is discarded. After a sequence of channel-read or put operations, invoke this method to prepare for a sequence of 3 min read Buffer array() methods in Java with Examples The array() method of java.nio.Buffer class is used to return the array that backs the taken buffer. This method is intended to allow array-backed buffers to be passed to native code more efficiently. Concrete subclasses provide more strongly-typed return values for this method. Modifications to thi 3 min read Buffer clear() methods in Java with Examples The clear() method of java.nio.ByteBuffer Class is used to clear this buffer. The position is set to zero, the limit is set to the capacity, and the mark is discarded. Invoke this method before using a sequence of channel-read or put operations to fill this buffer. For example: buf.clear(); // Prepa 3 min read Like