The array() method of java.nio.CharBuffer Class is used to return the char array that backs this buffer. Any modifications done to this buffer’s content will cause the returned array’s content also to be modified, and vice versa. hasArray() method is invoked before invoking this method in order to ensure that this buffer has an accessible backing array.
Syntax:
public final char[] array()
Return Value: This method returns the array that backs this buffer.
Throws: This method throws the ReadOnlyBufferException(If this buffer is backed by an array but is read-only)
Below program illustrates the array() method:
Example 1:
// Java program to demonstrate// array() method import java.nio.*;import java.util.*; public class GFG { public static void main(String[] args) { // Declaring the capacity of the CharBuffer int capacity = 10; // Creating the CharBuffer try { // creating object of CharBuffer // and allocating size capacity CharBuffer cb = CharBuffer.allocate(capacity); // putting the value in CharBuffer cb.put('a'); cb.put(2, 'b'); cb.rewind(); // getting array from cb // CharBuffer using array() method char[] cbb = cb.array(); // printing the CharBuffer cb System.out.println("CharBuffer: " + Arrays.toString(cbb)); } catch (IllegalArgumentException e) { System.out.println("IllegalArgumentException catched"); } catch (ReadOnlyBufferException e) { System.out.println("ReadOnlyBufferException catched"); } }} |
Output:
CharBuffer: [a, , b, , , , , , , ]
Example 2:
// Java program to demonstrate// array() method import java.nio.*;import java.util.*; public class GFG { public static void main(String[] args) { // Declaring the capacity of the cb int capacity1 = 10; // Declaring the capacity of the cb1 int capacity2 = 5; // Creating the CharBuffer try { // // cb // // creating object of CharBuffer cb // and allocating size capacity CharBuffer cb = CharBuffer.allocate(capacity1); // putting the value in cb cb.put('a'); cb.put(2, 'b'); cb.put(3, 'c'); cb.rewind(); // print the CharBuffer System.out.println("CharBuffer cb: " + Arrays.toString(cb.array())); // // cb1 // // creating object of CharBuffer cb1 // and allocating size capacity CharBuffer cb1 = CharBuffer.allocate(capacity2); // putting the value in cb1 cb1.put(1, 'd'); cb1.put(2, 'e'); cb1.rewind(); // print the CharBuffer System.out.println("\nCharBuffer cb1: " + Arrays.toString(cb1.array())); // Creating a read-only copy of CharBuffer // using asReadOnlyBuffer() method CharBuffer readOnlycb = cb.asReadOnlyBuffer(); // print the CharBuffer System.out.print("\nReadOnlyBuffer CharBuffer: "); while (readOnlycb.hasRemaining()) System.out.print(readOnlycb.get() + ", "); // try to change readOnlycb System.out.println("\n\nTrying to get the array" + " from ReadOnlycb for editing"); char[] cbarr = readOnlycb.array(); } catch (IllegalArgumentException e) { System.out.println("IllegalArgumentException catched"); } catch (ReadOnlyBufferException e) { System.out.println("Exception thrown: " + e); } }} |
Output:
CharBuffer cb: [a,, b, c,,,,,, ] CharBuffer cb1: [, d, e,, ] ReadOnlyBuffer CharBuffer: a,, b, c,,,,,,, Trying to get the array from ReadOnlycb for editing Exception thrown: java.nio.ReadOnlyBufferException
