36 lines
1.0 KiB
Java
36 lines
1.0 KiB
Java
// newio/ChannelCopy.java
|
|
// (c)2020 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.nio.*;
|
|
import java.nio.channels.*;
|
|
import java.io.*;
|
|
|
|
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);
|
|
}
|
|
}
|
|
}
|