InputStream与OutputStream的使用例子-白红宇

package com.hanchao.test;

import java.io.BufferedInputStream;

import java.io.BufferedOutputStream;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileOutputStream;

/**

* 测试类

* @author hanlw

* 2012 -07 - 04

public class Test_two {

public static void main(String[] args) throws Exception{

/**

* InputStream与OutputStream的使用例子

* (缓冲文件输入流)BufferedInputStream → (文件输入流)FileInputStream → (输入流)java.io.InputStream

* (缓冲文件输出流)BufferedOuputStream → (文件输出流)FileOuputStream → (输出流)java.io.OutputStream

/**

* 1.通过流复制一个图片的例子

/* File file = new File("c:/images/1.png");

File outfile = new File("C:/temp.png");

FileInputStream inputStream = new FileInputStream(file);

FileOutputStream outputStream = new FileOutputStream(outfile);

int i = 0;

while(i != -1) {

i = inputStream.read();

outputStream.write(i);

}

//注意流的关闭(必须的)

inputStream.close();

outputStream.close();

/**

* 2.如果我们想提高要提高复制的速度，可以采用缓冲文件输入\输出流，如下：

/* File file = new File("C:/images/1.png");

File outfile = new File("C:/temp1.jpg");

//文件输入流

FileInputStream inputStream = new FileInputStream(file);

//文件输出流

FileOutputStream outputStream = new FileOutputStream(outfile);

//缓冲文件输入流

BufferedInputStream bufferedInputStream = new BufferedInputStream(inputStream);

//缓冲文件输出流

BufferedOutputStream bufferedOutputStream = new BufferedOutputStream(outputStream);

int i = 0;

while(i != -1) {

i = bufferedInputStream.read();

bufferedOutputStream.write(i);

}

//流的关闭

bufferedOutputStream.flush();//强制清除缓冲区的内容

bufferedInputStream.close();

bufferedOutputStream.close();

/**

* 3.当文件很大,我们要做一个缓冲处理来提高速度。如下：当文件的大小大于512个字节时，每次读入512个字节后再做处理

/* File file = new File("C:/images/1.png");

File outfile = new File("C:/temp2.png");

//文件输入流

FileInputStream inputStream = new FileInputStream(file);

//文件输出流

FileOutputStream outputStream = new FileOutputStream(outfile);

int i = 0;

//缓冲大小为512字节

byte[] buffer = new byte[512];

while(true) {

if(inputStream.available() < 512) {

while(i != -1) {

i = inputStream.read();

outputStream.write(i);

}

break;//注意此处不能忘记哦

} else {

//当文件的大小大于512字节时

inputStream.read(buffer);

outputStream.write(buffer);

}

//流的关闭

//注意流的关闭(必须的)

inputStream.close();

outputStream.close();

/**

* 4.根据上面的例子，我们可以知道：我们可以做一个双缓冲的文件复制

File file = new File("C:/images/1.png");

File outfile = new File("C:/temp3.png");

//文件输入流

FileInputStream inputStream = new FileInputStream(file);

//文件输出流

FileOutputStream outputStream = new FileOutputStream(outfile);

//缓冲文件输入流

BufferedInputStream bufferedInputStream = new BufferedInputStream(inputStream);

//缓冲文件输出流

BufferedOutputStream bufferedOutputStream = new BufferedOutputStream(outputStream);

int i = 0;

//缓冲区的大小

byte[] buffer = new byte[512];

while(true) {

if(bufferedInputStream.available() < 512) {

while(i != -1) {

i = bufferedInputStream.read();

bufferedOutputStream.write(i);

}

break;

} else {

//当文件的大小还大于512字节时

bufferedInputStream.read(buffer);

bufferedOutputStream.write(buffer);

}

//强制清空缓冲区的内容

bufferedOutputStream.flush();

//流的关闭

bufferedInputStream.close();

bufferedOutputStream.close();

}

本文转自韩立伟 51CTO博客，原文链接：http://blog.51cto.com/hanchaohan/922335

，如需转载请自行联系原作者