public static long forChannel(File f1, File f2) throws Exception {
  long time = new Date().getTime();
  int size = 2*1024;

  FileInputStream in = new FileInputStream(f1);
  FileOutputStream out = new FileOutputStream(f2);

  FileChannel inC = in.getChannel();
  FileChannel outC = out.getChannel();

  ByteBuffer buffer = null;
  int count = size;
  while (inC.position() != inC.size()) {
   if ((inC.size() - inC.position()) < size) {
    count = (int) (inC.size() - inC.position());
   }
   buffer = ByteBuffer.allocateDirect(count);
   
   inC.read(buffer);
   
   buffer.flip();
   
   outC.write(buffer);
   
   outC.force(false);
  }
  inC.close();
  outC.close();
  
  in.close();
  out.flush();
  out.close();
  return new Date().getTime() - time;
 }
 
 public static long forChannelOne(File f1, File f2) throws IOException {
  long time = new Date().getTime();
  int size = 2 * 1024;// 2097152;
  FileInputStream in = new FileInputStream(f1);
  FileOutputStream out = new FileOutputStream(f2);

  FileChannel fcin = in.getChannel();
  FileChannel fcout = out.getChannel();

  ByteBuffer buffer = ByteBuffer.allocate(size); // 分配2KB作為緩衝區

  while (true) {
   buffer.clear(); // 每次使用必須置空緩衝區

   int r = fcin.read(buffer);

   if (r == -1) {
    break;
   }

   buffer.flip(); // 寫入前使用flip這個方法

   fcout.write(buffer);
  }

  fcin.close();
  fcout.close();

  in.close();
  out.flush();
  out.close();
  return new Date().getTime() - time;
 }

 
 public static long forJava(File f1, File f2) throws Exception {
  long time = new Date().getTime();
  int size = 2 * 1024;// 2097152;
  FileInputStream in = new FileInputStream(f1);
  FileOutputStream out = new FileOutputStream(f2);

  byte[] buffer = new byte[size];
  int ins;
  while ((ins = in.read(buffer)) != -1) {
   out.write(buffer, 0, ins);
  }

  in.close();
  out.flush();
  out.close();
  return new Date().getTime() - time;
 }

 
 public static long forTransfer(File f1, File f2) throws Exception {
  long time = new Date().getTime();
  int size = 2 * 1024;// 2k == 2097152;
  FileInputStream in = new FileInputStream(f1);
  FileOutputStream out = new FileOutputStream(f2);

  FileChannel inC = in.getChannel();
  FileChannel outC = out.getChannel();

  int count = size;
  while (inC.position() != inC.size()) {
   if ((inC.size() - inC.position()) < size) {
    count = (int) (inC.size() - inC.position());
   }
   inC.transferTo(inC.position(), count, outC);
   inC.position(inC.position() + count);
  }
  inC.close();
  outC.close();
  return new Date().getTime() - time;
 }

public void test(){
  String infile = "/sdcard/testUTF.txt"; //8k
  String outfile = "/sdcard/testUTF8.txt";
  File f1 = new File(infile);
  File f2 = new File(outfile);
  try {
//   Log.v("TAG", "" + Student.forJava(f1, f2));//31
//   Log.v("TAG", "" + Student.forTransfer(f1, f2));//28
   Log.v("TAG", "" + Student.forChannelOne(f1, f2));//22
//   Log.v("TAG", "" + Student.forChannel(f1, f2));//15
  } catch (Exception e) {
   e.printStackTrace();
  }

參考貼:http://blog.csdn.net/ta8210/archive/2008/01/30/2073817.aspx