What ist the fastest way to copy a big number of files in Java. So far I have used file streams and nio. Overall streams seem to be faster than nio. What experiences did you make so far?
What ist the fastest way to copy a big number of files in Java. So far I have used file streams and nio. Overall streams seem to be faster than nio. What experiences did you make so far?
Using Stream
private static void copyFileUsingStream(File source, File dest) throws IOException {
InputStream is = null;
OutputStream os = null;
try {
is = new FileInputStream(source);
os = new FileOutputStream(dest);
byte[] buffer = new byte[1024];
int length;
while ((length = is.read(buffer)) > 0) {
os.write(buffer, 0, length);
}
} finally {
is.close();
os.close();
}
}
Using Channel
private static void copyFileUsingChannel(File source, File dest) throws IOException {
FileChannel sourceChannel = null;
FileChannel destChannel = null;
try {
sourceChannel = new FileInputStream(source).getChannel();
destChannel = new FileOutputStream(dest).getChannel();
destChannel.transferFrom(sourceChannel, 0, sourceChannel.size());
}finally{
sourceChannel.close();
destChannel.close();
}
}
Using Apache Commons IO
private static void copyFileUsingApacheCommonsIO(File source, File dest) throws IOException {
FileUtils.copyFile(source, dest);
}
Using Java SE 7 Files
private static void copyFileUsingJava7Files(File source, File dest) throws IOException {
Files.copy(source.toPath(), dest.toPath());
}
Performance test
File source = new File("/Users/tmp/source.avi");
File dest = new File("/Users/tmp/dest.avi");
//copy file conventional way using Stream
long start = System.nanoTime();
copyFileUsingStream(source, dest);
System.out.println("Time taken by Stream Copy = "+(System.nanoTime()-start));
//copy files using java.nio FileChannel
source = new File("/Users/tmp/sourceChannel.avi");
dest = new File("/Users/tmp/destChannel.avi");
start = System.nanoTime();
copyFileUsingChannel(source, dest);
System.out.println("Time taken by Channel Copy = "+(System.nanoTime()-start));
//copy files using apache commons io
source = new File("/Users/tmp/sourceApache.avi");
dest = new File("/Users/tmp/destApache.avi");
start = System.nanoTime();
copyFileUsingApacheCommonsIO(source, dest);
System.out.println("Time taken by Apache Commons IO Copy = "+(System.nanoTime()-start));
//using Java 7 Files class
source = new File("/Users/tmp/sourceJava7.avi");
dest = new File("/Users/tmp/destJava7.avi");
start = System.nanoTime();
copyFileUsingJava7Files(source, dest);
System.out.println("Time taken by Java7 Files Copy = "+(System.nanoTime()-start));
RESULTS
Time taken by Stream Copy = 44,582,575,000
Time taken by Java7 Files Copy = 89,061,578,000
Time taken by Channel Copy = 104,138,195,000
Time taken by Apache Commons IO Copy = 108,396,714,000
Its depend of files(bigger files), for me is fastest way this one with buffered stream
public void copyFile(File inFileStr, File outFileStr) throws IOException {
try (BufferedInputStream bis = new BufferedInputStream(new FileInputStream(inFileStr));
BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(outFileStr))) {
byte[] buffer = new byte[1024 * 1024];
int read = 0;
while ((read = bis.read(buffer)) != -1) {
bos.write(buffer, 0, read);
}
bis.close();
bos.close();
} catch (IOException ex) {
ex.printStackTrace();
}
}