The rewind() method of java.nio.CharBuffer Class is used to rewind this buffer. The position is set to zero and the mark is discarded. Invoke this method before a sequence of channel-write or get operations, assuming that the limit has already been set appropriately. Invoking this method neither changes nor discards the mark’s value.
Syntax:
public ByteBuffer rewind()
Return Value: This method returns this buffer.
Below are the examples to illustrate the rewind() method:
Examples 1:
// Java program to demonstrate // rewind() method import java.nio.*;
import java.util.*;
public class GFG {
public static void main(String[] args)
{
// defining and allocating CharBuffer
// using allocate() method
CharBuffer charBuffer = CharBuffer.allocate( 4 );
// put char value in charBuffer
// using put() method
charBuffer.put( 'a' );
charBuffer.put(( char ) 105 );
// print the char buffer
System.out.println( "Buffer before operation: "
+ Arrays.toString(
charBuffer.array())
+ "\nPosition: "
+ charBuffer.position()
+ "\nLimit: "
+ charBuffer.limit());
// rewind the Buffer
// using rewind() method
charBuffer.rewind();
// print the charbuffer
System.out.println( "\nBuffer after operation: "
+ Arrays.toString(
charBuffer.array())
+ "\nPosition: "
+ charBuffer.position()
+ "\nLimit: "
+ charBuffer.limit());
}
} |
Output:
Buffer before operation: [a, i,, ] Position: 2 Limit: 4 Buffer after operation: [a, i,, ] Position: 0 Limit: 4
Examples 2:
// Java program to demonstrate // rewind() method import java.nio.*;
import java.util.*;
public class GFG {
public static void main(String[] args)
{
// defining and allocating CharBuffer
// using allocate() method
CharBuffer charBuffer
= CharBuffer.allocate( 5 );
// put byte value in charBuffer
// using put() method
charBuffer.put( 'a' );
charBuffer.put( 'b' );
charBuffer.put( 'c' );
// mark will be going to discarded by rewind()
charBuffer.mark();
// print the buffer
System.out.println( "Buffer before operation: "
+ Arrays.toString(
charBuffer.array())
+ "\nPosition: "
+ charBuffer.position()
+ "\nLimit: "
+ charBuffer.limit());
// Rewind the Buffer
// using rewind() method
charBuffer.rewind();
// print the buffer
System.out.println( "\nBuffer after operation: "
+ Arrays.toString(
charBuffer.array())
+ "\nPosition: "
+ charBuffer.position()
+ "\nLimit: "
+ charBuffer.limit());
}
} |
Output:
Buffer before operation: [a, b, c,, ] Position: 3 Limit: 5 Buffer after operation: [a, b, c,, ] Position: 0 Limit: 5
Reference: https://docs.oracle.com/javase/9/docs/api/java/nio/CharBuffer.html#rewind–