FileInputStream,FileOutputStream文件拷贝之性能比较


package com.kingsoft.main;

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

public class TestIO03 {

/**
* @param args
* @throws IOException
*/
public static void main(String[] args) throws IOException {

InputStream ins = new FileInputStream(
"E:\\tools\\FreeMind-Windows-Installer-0.8.1-max.exe");
OutputStream ous = new FileOutputStream(
"D:\\FreeMind-Windows-Installer-0.8.1-max.exe_bk");

byte[] contents = new byte[ins.available()];

long start = System.currentTimeMillis();
// 读取文件
int i = 0;
int count = 0;
while ((i = ins.read()) != -1) {
contents[count] = (byte) i;
count++;
}

long end = System.currentTimeMillis();
System.out.println("读取耗时:" + (end - start) + "毫秒");

start = System.currentTimeMillis();
// 输出文件
for (int j = 0; j < contents.length; j++) {
ous.write(contents[j]);
}

end = System.currentTimeMillis();
System.out.println("读取耗时:" + (end - start) + "毫秒");

ins.close();
ous.flush();
ous.close();
}
}

执行结果如下:
读取耗时:13329毫秒
读取耗时:16083毫秒


InputStream ins = new FileInputStream(
"E:\\tools\\FreeMind-Windows-Installer-0.8.1-max.exe");
OutputStream ous = new FileOutputStream(
"D:\\FreeMind-Windows-Installer-0.8.1-max.exe_bk");

long start = System.currentTimeMillis();
int i = 0;
while ((i = ins.read()) != -1) {
ous.write(i);
}

long end = System.currentTimeMillis();
System.out.println("耗时:" + (end - start) + "毫秒");

ins.close();
ous.flush();
ous.close();

执行结果如下:
耗时:30013毫秒


InputStream ins = new FileInputStream(
"E:\\tools\\FreeMind-Windows-Installer-0.8.1-max.exe");
OutputStream ous = new FileOutputStream(
"D:\\FreeMind-Windows-Installer-0.8.1-max.exe_bk");

byte[] contents = new byte[ins.available()];

long start = System.currentTimeMillis();
ins.read(contents);
ous.write(contents);

long end = System.currentTimeMillis();
System.out.println("耗时:" + (end - start) + "毫秒");

ins.close();
ous.flush();
ous.close();

执行结果如下:
耗时:2384毫秒
评论
添加红包

请填写红包祝福语或标题

红包个数最小为10个

红包金额最低5元

当前余额3.43前往充值 >
需支付:10.00
成就一亿技术人!
领取后你会自动成为博主和红包主的粉丝 规则
hope_wisdom
发出的红包
实付
使用余额支付
点击重新获取
扫码支付
钱包余额 0

抵扣说明:

1.余额是钱包充值的虚拟货币,按照1:1的比例进行支付金额的抵扣。
2.余额无法直接购买下载,可以购买VIP、付费专栏及课程。

余额充值