④

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;

public class CopyFile {

 /**
  * @param args
  */
 public static void copy(File a,File b){
  try {
   FileInputStream fis = new FileInputStream("a.mp3");
   FileOutputStream fos = new FileOutputStream("temp.mp3");
    //改进方法代码
   byte[] buf = new byte[2008];
   int length;
   int read = fis.read();
   while((length = fis.read(buf))!=-1){
    fos.write(buf, 0, length);
   //
   }
   fis.close();
   fos.close();
  } catch (IOException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }
 }
 public static void main(String[] args) {
  // TODO Auto-generated method stub
  //测试时间代码
  File a = new File("");
  File b = new File("");
  long start,end;
  start = System.currentTimeMillis();
  copy(a,b);
  end = System.currentTimeMillis();
  System.out.println("用时：" + (end - start) + "ms");
 //
 }
}