Java输入输出流复制文件所用时间对比
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
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