緩衝流是一種處理流，需要套在節點流上使用，能提高寫入或讀取的速度

測試未加緩衝流和加緩衝流在速度上的差異，拷貝870M大小的檔案,BufferedInputStream 位元組輸入流和BufferedOutputStream位元組輸出流

package com.mike.io.eg;

import java.io.IOException;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.File;

/**
 * @author mike
 * @date 2020-11-26
 * @desc 位元組輸入緩衝流,測試無緩衝流拷貝檔案
 */
public class BufferedInputStreamDemo {
	public static void main(String[] args) {
		//定義輸入流
		FileInputStream fis = null;
		FileOutputStream fos = null;
		File source = new File("D:\\系統映象\\ubuntu-18.04.4-live-server-amd64.iso");
		File target = new File("F:\\ubuntu-18.04.4-live-server-amd64.iso");
		try {
			long start = System.currentTimeMillis();
			fis = new FileInputStream(source);
			fos = new FileOutputStream(target);
			byte[] buffer = new byte[1024];
			int len = 0;
			while((len = fis.read(buffer)) != -1) {
				fos.write(buffer,0,len);
			}
			long end = System.currentTimeMillis();
			System.out.println("拷貝成功,一共耗時" + (end - start) / 60 + "s" );//74s
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			try {
				fis.close();
				fos.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}

	}
}


 

輸出結果

package com.mike.io.eg;

import java.io.IOException;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;

/**
 * @author mike
 * @date 2020-11-26
 * @desc 位元組緩衝輸出流，測試加緩衝流拷貝檔案時間
 */
public class BufferedOutputStreamDemo1 {
	public static void main(String[] args) {
		File source = new File("D:\\系統映象\\ubuntu-18.04.4-live-server-amd64.iso");
		File target = new File("F:\\ubuntu-18.04.4-live-server-amd64.iso");
		BufferedInputStream bis = null;
		BufferedOutputStream bos = null;
		try {
			long start = System.currentTimeMillis();
			bis = new BufferedInputStream(new FileInputStream(source));
			bos = new BufferedOutputStream(new FileOutputStream(target));
			int len = 0;
			byte[] buffer = new byte[1024];
			while((len = bis.read(buffer)) != -1) {
				bos.write(buffer,0,len);
			}
			long end = System.currentTimeMillis();
			System.out.println("拷貝完成,一共耗時" + (end-start)/60 + "s" );
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			try {
				bis.close();
				bos.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}

	}
}

 

輸出結果

測試結果表明使用緩衝流讀寫檔案時間會縮短3分之一，強烈建議使用緩衝流