CharBuffer asReadOnlyBuffer() method in Java
The asReadOnlyBuffer() method of java.nio.CharBuffer Class is used to create a new, read-only char buffer with this buffer’s content. The new buffer is a replica of this buffer. Hence changes made to this buffer’s content will be visible in the new buffer.
Since the new buffer is read-only, therefore any modification to its content won’t be allowed. The two buffers’ position, limit, and mark values will be independent. The new buffer’s capacity, limit, position, and mark values will be identical to those of this buffer. If this buffer is itself read-only then this method behaves in exactly the same way as the duplicate method.
Syntax :
public abstract CharBuffer asReadOnlyBuffer()
Return Value: This method returns the new, read-only char buffer with the same content as that of this buffer.
Below are the examples to illustrate the asReadOnlyBuffer() method:
Examples 1:
import java.nio.*;
import java.util.*;
public class GFG {
public static void main(String[] args)
{
int capacity = 10 ;
try {
CharBuffer cb = CharBuffer.allocate(capacity);
cb.put( 'a' );
cb.put( 2 , 'b' );
cb.rewind();
System.out.println( "Original CharBuffer: "
+ Arrays.toString(cb.array()));
CharBuffer charBuffer = cb.asReadOnlyBuffer();
System.out.print( "\nReadOnlyBuffer CharBuffer: " );
while (charBuffer.hasRemaining())
System.out.print(charBuffer.get() + ", " );
}
catch (IllegalArgumentException e) {
System.out.println( "IllegalArgumentException catched" );
}
catch (ReadOnlyBufferException e) {
System.out.println( "ReadOnlyBufferException catched" );
}
}
}
|
Output:
Original CharBuffer: [a, , b, , , , , , , ]
ReadOnlyBuffer CharBuffer: a, , b, , , , , , , ,
Examples 2:
import java.nio.*;
import java.util.*;
public class GFG {
public static void main(String[] args) throws Exception
{
int capacity1 = 10 ;
int capacity2 = 5 ;
try {
CharBuffer cb = CharBuffer.allocate(capacity1);
cb.put( 'a' );
cb.put( 2 , 'b' );
cb.rewind();
System.out.println( "CharBuffer cb: "
+ Arrays.toString(cb.array()));
CharBuffer cb1 = CharBuffer.allocate(capacity2);
cb1.put( 1 , 'c' );
cb1.put( 2 , 'd' );
cb1.rewind();
System.out.println( "\nCharBuffer cb1: "
+ Arrays.toString(cb1.array()));
CharBuffer readOnlyCb = cb.asReadOnlyBuffer();
System.out.print( "\nReadOnlyBuffer CharBuffer: " );
while (readOnlyCb.hasRemaining())
System.out.print(readOnlyCb.get() + ", " );
System.out.println( "\n\nTrying to get the array"
+ " from ReadOnlyCb for editing" );
char [] fbarr = readOnlyCb.array();
}
catch (IllegalArgumentException e) {
System.out.println( "IllegalArgumentException catched" );
}
catch (ReadOnlyBufferException e) {
System.out.println( "Exception thrown: " + e);
}
}
}
|
Output:
CharBuffer cb: [a, , b, , , , , , , ]
CharBuffer cb1: [ , c, d, , ]
ReadOnlyBuffer CharBuffer: a, , b, , , , , , , ,
Trying to get the array from ReadOnlyCb for editing
Exception thrown: java.nio.ReadOnlyBufferException
Last Updated :
19 Sep, 2018
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