121.借助文件拷贝设置对照组测试字节缓冲的效率提升

借助 "118.IO工具类"中的copy设立对照组，测试字节缓冲对性能的提升

package cn.yzy.io;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

public class testProductivityOfBufferedStream {
     
	public static void main(String[] args) {
     
		//不使用字节缓冲流
		long t1 = System.currentTimeMillis();
		copy5("182.181_IO_字节缓冲流.mp4", "copy.mp4");
		long t2 = System.currentTimeMillis();
		System.out.println(t2 - t1);
		
		//使用字节缓冲流
		long t3 = System.currentTimeMillis();
		copy6("182.181_IO_字节缓冲流.mp4", "copy.mp4");
		long t4 = System.currentTimeMillis();
		System.out.println(t4 - t3);
	}
	public static void copy5(String srcPath, String destPath) {
     
		//创建源
		File srcFile = new File(srcPath);
		File destFile = new File(destPath);
		
		try(InputStream inputStream = new FileInputStream(srcFile);
				OutputStream outputStream = new FileOutputStream(destFile)) {
     
			//分段读取
			byte[] flush = new byte[1024];
			int len = -1;
			while((len = inputStream.read(flush)) != -1) {
     
				outputStream.write(flush, 0, len);
			}
			
		}catch (FileNotFoundException e) {
     
			e.printStackTrace();
		}catch (IOException e) {
     
			e.printStackTrace();
		}
	}
	
	public static void copy6(String srcPath, String destPath) {
     
		//创建源
		File srcFile = new File(srcPath);
		File destFile = new File(destPath);
		
		try(InputStream inputStream = new BufferedInputStream(new FileInputStream(srcFile));
				OutputStream outputStream = new BufferedOutputStream(new FileOutputStream(destFile))) {
     
			//分段读取
			byte[] flush = new byte[1024];
			int len = -1;
			while((len = inputStream.read(flush)) != -1) {
     
				outputStream.write(flush, 0, len);
			}
			
		}catch (FileNotFoundException e) {
     
			e.printStackTrace();
		}catch (IOException e) {
     
			e.printStackTrace();
		}
	}
}

发现使用字节缓冲流可以极大的提高数据文件拷贝速度