高效的RandomAccessFile

RandomAccessFile rafr,rafw;
rafr = new RandomAccessFile("F:\\ha.rar", "r");
rafw = new RandomAccessFile(".\\004.rar", "rw");
        
byte[] buffer=new byte[1024];

start = System.currentTimeMillis();
while((readcount = rafr.read(buffer)) != -1) {
        	rafw.write(buffer, 0, readcount);
}
rafr.close();
rafw.close();
System.out.println("RandomAccessFile Copy & Write File: "
      + brafReadFile.filename
      + "    FileSize: "
      + java.lang.Integer.toString((int)readfilelen >> 1024)
      + " (KB)    "
      + "Spend: "
      + (double)(System.currentTimeMillis()-start) / 1000
      + "(s)");