Java speeds up reading and copying large files

File channel (FileChannel) to achieve file replication, for your reference, the specific contents are as follows

Regardless of multithreaded optimization, the fastest method for single-threaded file copy is (the larger the file, the more advantageous this method is, which is generally 30 +% faster than common methods):

Directly on the code:

package test;
 import java.io.BufferedInputStream;
 import java.io.BufferedOutputStream;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.nio.channels.FileChannel;

 public class Test {
public static void main(String[] args) {
File source = new File("E:\\tools\\fmw_12.1.3.0.0_wls.jar");
File target = new File("E:\\tools\\fmw_12.1.3.0.0_wls-copy.jar");
long start, end;

start = System.currentTimeMillis();
fileChannelCopy(source, target);
end = System.currentTimeMillis();
System.out.println(" File channel time: " + (end - start) + " Milliseconds ");

start = System.currentTimeMillis();
copy(source, target);
end = System.currentTimeMillis();
System.out.println(" Ordinary buffer time: " + (end - start) + " Milliseconds ");
}

/**
 *  Copy files using file channels 
 * @param source  Source file 
 * @param target  Object file 
 */
 public static void fileChannelCopy(File source, File target) {


  FileInputStream in = null;
  FileOutputStream out = null;
  FileChannel inChannel = null;
  FileChannel outChannel = null;
  try {
  in = new FileInputStream(source);
  out = new FileOutputStream(target);
  inChannel = in.getChannel();// Get the corresponding file channel 
  outChannel = out.getChannel();// Get the corresponding file channel 
  inChannel.transferTo(0, inChannel.size(), outChannel);// Connect the two channels and derive from the inChannel Channel read and then write to outChannel Channel 
 } catch (IOException e) {
  e.printStackTrace();
  } finally {
  try {
   in.close();
   inChannel.close();
   out.close();
   outChannel.close();
  } catch (IOException e) {
   e.printStackTrace();
  }


  }


 }
 
/**
*  Normal buffer replication 
* @param source  Source file 
* @param target  Object file 
*/
public static void copy (File source, File target) {
InputStream in = null;
BufferedOutputStream out = null;
try {
in = new BufferedInputStream(new FileInputStream(source));
out = new BufferedOutputStream(new FileOutputStream(target));
byte[] buf = new byte[4096];
int i;
while ((i = in.read(buf)) != -1) {
out.write(buf, 0, i);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
if (null != in) {
in.close();
}
if (null != out) {
out.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
 }

 }