// newio/ChannelCopy.java

// (c)2017 MindView LLC: see Copyright.txt

// We make no guarantees that this code is fit for any purpose.

// Visit http://OnJava8.com for more book information.

// Copying a file using channels and buffers

// {java ChannelCopy ChannelCopy.java test.txt}

import java.io.FileInputStream;

import java.io.FileOutputStream;

import java.io.IOException;

import java.nio.ByteBuffer;

import java.nio.channels.FileChannel;

public class ChannelCopy {

private static final int BSIZE = 1024;

public static void main(String[] args) {

if (args.length != 2) {

System.out.println(

"arguments: sourcefile destfile");

System.exit(1);

}

try (

FileChannel in = new FileInputStream(

args[0]).getChannel();

FileChannel out = new FileOutputStream(

args[1]).getChannel()

) {

ByteBuffer buffer = ByteBuffer.allocate(BSIZE);

while (in.read(buffer) != -1) {

buffer.flip(); // Prepare for writing

out.write(buffer);

buffer.clear(); // Prepare for reading

}

} catch (IOException e) {

throw new RuntimeException(e);

}

}

}