ByteBuffer allocate() method in Java

A new ByteBuffer can be allocated using the method allocate() in the class java.nio.ByteBuffer. This method requires a single parameter i.e. the capacity of the buffer. It returns the new ByteBuffer that is allocated. If the capacity provided is negative, then the IllegalArgumentException is thrown.

A program that demonstrates this is given as follows −

Example

 Live Demo

import java.nio.*; import java.util.*; public class Demo {    public static void main(String[] args) {       int n = 5;       try {          ByteBuffer buffer = ByteBuffer.allocate(n);          buffer.put((byte)1);          buffer.put((byte)2);          buffer.put((byte)3);          buffer.put((byte)4);          buffer.put((byte)5);          buffer.rewind();          System.out.println("The ByteBuffer is: " + Arrays.toString(buffer.array()));       } catch (IllegalArgumentException e) { System.out.println("Error!!! IllegalArgumentException"); } catch (ReadOnlyBufferException e) { System.out.println("Error!!! ReadOnlyBufferException"); } } }

Output

The ByteBuffer is: [1, 2, 3, 4, 5]