废话不多说，关键代码如下所述：

package com.edu.xynu; import java.io.BufferedInputStream; import java.io.BufferedOutputStream; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; public class IOUnitCopy { //按字节 public static void copyByByte(File srcFile,File destFile) throws IOException{ FileInputStream fis=new FileInputStream(srcFile); FileOutputStream fos=new FileOutputStream(destFile); int i; while((i=fis.read())!=-1){ fos.write(i); } fis.close(); fos.close(); } //按字节数组 public static void copyByByteArray(File srcFile,File destFile) throws IOException{ FileInputStream fis=new FileInputStream(srcFile); FileOutputStream fos=new FileOutputStream(destFile); byte []buf=new byte[10*1024]; int i; while((i=fis.read(buf, 0, buf.length))!=-1){ fos.write(buf, 0, i); } fis.close(); fos.close(); } //字节缓冲流 public static void copyByBuff(File srcFile,File destFile) throws IOException{ BufferedInputStream bis=new BufferedInputStream(new FileInputStream(srcFile)); BufferedOutputStream bos=new BufferedOutputStream(new FileOutputStream(destFile)); int i; while((i=bis.read())!=-1){ bos.write(i); } bos.flush(); bis.close(); bos.close(); } //字节数组批量读取 缓冲输出流写入 public static void copyByBuffArray(File srcFile,File destFile) throws IOException{ FileInputStream bis=new FileInputStream(srcFile); BufferedOutputStream bos=new BufferedOutputStream(new FileOutputStream(destFile)); byte [] buf=new byte[10*1024]; int len; while((len=bis.read(buf,0,buf.length))!=-1){ bos.write(buf,0,len); } bos.flush(); bis.close(); bos.close(); } } package com.edu.xynu; import java.io.File; import java.io.IOException; public class IOUnitsCopyTest { public static void main(String[] args) { // TODO Auto-generated method stub try { long start=System.currentTimeMillis(); // IOUnitCopy.copyByByte(new File("c:1.mp3"), new File( // "c:2.mp3"));//90713ms // IOUnitCopy.copyByByteArray(new File("c:1.mp3"), new File( // "c:3.mp3"));//41ms // IOUnitCopy.copyByBuff(new File("c:1.mp3"), new File( // "c:4.mp3"));//556ms // IOUnitCopy.copyByByteArray(new File("c:1.mp3"), new File( // "c:5.mp3"));//30ms long end=System.currentTimeMillis(); System.out.println(end-start); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } }

测试文件是