Copying Files with FileChannel and a Direct ByteBuffer - Java File Path IO

Java examples for File Path IO:File Channel

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Description

Copying Files with FileChannel and a Direct ByteBuffer

Demo Code

import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.StandardOpenOption;
import java.util.EnumSet;

public class Main {
  public static void main(String[] args) {
    Path copy_from = Paths.get("C:/folder1/folder2/folder3/videos/test.mp4");
    Path copy_to = Paths.get("C:/test.mp4");
    int bufferSizeKB = 4;
    int bufferSize = bufferSizeKB * 1024;
    System.out.println("Using FileChannel and direct buffer ...");
    try (FileChannel fileChannel_from = (FileChannel.open(copy_from,
        EnumSet.of(StandardOpenOption.READ)));
        FileChannel fileChannel_to = (FileChannel
            .open(copy_to, EnumSet.of(StandardOpenOption.CREATE_NEW,
                StandardOpenOption.WRITE)))) {
      ByteBuffer bytebuffer = ByteBuffer.allocateDirect(bufferSize);
      int bytesCount;
      while ((bytesCount = fileChannel_from.read(bytebuffer)) > 0) {
        bytebuffer.flip();//from  w  ww.  jav  a 2s  .  co  m
        fileChannel_to.write(bytebuffer);
        bytebuffer.clear();
      }
    } catch (IOException ex) {
      System.err.println(ex);
    }
  }
}

Result


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