http://www.techscore.com/tech/J2SE/NIO/index.html
http://www.javainthebox.net/laboratory/JDK1.4/contents.html

 import java.io.*;
 import java.nio.*;
 import java.nio.channels.*;
 
 public class test {
   public static void main(String[] args){
     new test();
   }
   
   public test(){
     copyFileByStream("data.dat", "data_stream.dat");
     copyFileByChannel("data.dat", "data_channels.dat");
   }
   
   public void copyFileByChannel(String srcFilename, String destFilename){
     try{
       FileChannel in = (new FileInputStream(srcFilename)).getChannel();
       FileChannel out = (new FileOutputStream(destFilename)).getChannel();
       
       long start = System.currentTimeMillis();
       
       ByteBuffer buffer = ByteBuffer.allocateDirect(10000000);
       
       while (true) {
         buffer.clear();
         if(in.read(buffer) < 0){
           break;
         }
         buffer.flip();
         out.write(buffer);
       }
       
       long end = System.currentTimeMillis();
       
       System.out.println("Total time = " + (end-start));
       
       out.close();
       in.close();
     }catch(FileNotFoundException ex){
       ex.printStackTrace();
     }catch(IOException ex){
       ex.printStackTrace();
     }
   }
   public void copyFileByStream(String srcFilename, String destFilename){
     try{
       // InputStream in = new FileInputStream(srcFilename);
       // OutputStream out = new FileOutputStream(destFilename);
       BufferedInputStream in = new BufferedInputStream(new FileInputStream(srcFilename));
       BufferedOutputStream out = new BufferedOutputStream(new FileOutputStream(destFilename));
       
       long start = System.currentTimeMillis();
       
       byte[] buffer = new byte[10000000];
       int n;
       while ((n = in.read(buffer)) != -1) {
         out.write(buffer, 0, n);
       }
       
       out.flush();
       
       long end = System.currentTimeMillis();
       
       System.out.println("Total time = " + (end-start));
       out.close();
       in.close();
     }catch(FileNotFoundException ex){
       ex.printStackTrace();
     }catch(IOException ex){
       ex.printStackTrace();
     }
   }
 }

{{category2 プログラミング言語,Java}}