java中提供带缓冲的输入输出流。在打开文件进行写入或读取操作时，都会加上缓冲，提高了IO读写性能。

1. BufferedInputStream 缓冲输入流

2. BufferedOutputStream 缓冲输出流

使用带缓冲的输入输出流写一个拷贝文件的操作。

package com.dcz.io;

import java.io.BufferedInputStream;

import java.io.BufferedOutputStream;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileOutputStream;

public class BufferStream {

	/**

	 * 拷贝文件带缓冲

	 *

	 * @param srcFile

	 * @param destFile

	 * @throws Exception

	 */

	public static void copyFileByBuffer(File srcFile, File destFile)

			throws Exception {

		// 缓冲输入流

		BufferedInputStream bufferInputStream = new BufferedInputStream(

				new FileInputStream(srcFile));

		// 缓冲输出流

		BufferedOutputStream bufferOutputStream = new BufferedOutputStream(

				new FileOutputStream(destFile));

		int bytes = 0;

		while ((bytes = bufferInputStream.read()) != -1) {

			bufferOutputStream.write(bytes);

			bufferOutputStream.flush();

		}

		bufferOutputStream.close();

		bufferInputStream.close();

	}

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

		BufferStream.copyFileByBuffer(new File("D:\\cglib-3.1.jar"), new File(

				"D:\\aa.jar"));

	}

}