Main.java:

import java.nio.channels.*;
import java.nio.*;
import java.io.*;
 
public class Main
{
   public static void main(String []args) throws Exception {
      byte[] buffer = "contents of the buffer".getBytes();
      ByteArrayInputStream bais = new ByteArrayInputStream(buffer);
 
      ReadableByteChannel byteChannel = Channels.newChannel(bais);   
      ByteBuffer bb = ByteBuffer.allocate(10);
      
      int n;
      while ((n = byteChannel.read(bb)) > -1) {
         bb.rewind();
         
         for (int i=0; i<n; i++) {
            System.out.print((char) bb.get());
         }
      }
   }
}