IO读写（复制）视频练习

package com.chen.io1;

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

/**

• IO练习，一个复制视频的类
• 练习文件为大小1,443,621 字节的wmv视频文件
• @author Administrator

/ public class CopyVideo { /* * 方法一 * 基础复制方法 * 使用InputStream，OutputStream * 测试结果：基础复制花费时间：10367毫秒； * @param fromFileName * @param toFileName */ public static void baseCopyMethod(String fromFileName,String toFileName) { long startTime = System.currentTimeMillis(); InputStream in = null; OutputStream out = null; try { in = new FileInputStream(fromFileName); out = new FileOutputStream(toFileName); int tempRead ; while((tempRead = in.read())>-1) { out.write(tempRead); out.flush(); } } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); }finally { try { if(in!=null)in.close(); if(out!=null)out.close(); } catch (IOException e) { e.printStackTrace(); } } long endTime = System.currentTimeMillis(); long spendTime = endTime - startTime; System.out.println("方法一，基础复制花费时间："+ spendTime + "毫秒；"); }

/**
 * 方法二
 * 使用InputStream，OutputStream，并增加字节数组作为缓冲区，提升效率
 * 方法二，增加缓存后复制用时：121毫秒
 * @param fromFileName
 * @param toFileName
 */
public static void baseCopyMethod2(String fromFileName,String toFileName) {
	long startTime = System.currentTimeMillis();
	InputStream in = null;
	OutputStream out = null;
	
	try {
		in = new FileInputStream(fromFileName);
		out = new FileOutputStream(toFileName);
		byte[] buf = new byte[102];//缓冲区数组，减少硬盘的读取操作
		int tempRead ;
		while((tempRead=in.read(buf))>-1) {
			out.write(buf);
			out.flush();
		}
	} catch (FileNotFoundException e) {
		e.printStackTrace();
	} catch (IOException e) {
		e.printStackTrace();
	}finally {
		try {
			if(in!=null)in.close();
			if(out!=null)out.close();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
	long endTime = System.currentTimeMillis();
	long spendTime = endTime - startTime;
	System.out.println("方法二，增加缓存后复制用时："+ spendTime + "毫秒");
}

/**
 * 方法三
 * 方法三，使用BufferedInputStream和BufferedOutputStream
 * 方法三，使用BufferedInputStream和BufferedOutputStream后复制用时：8268毫秒
 * @param fromFileName
 * @param toFileName
 */
public static void bufferedCopyMethod(String fromFileName,String toFileName ) {
	long startTime = System.currentTimeMillis();
	BufferedInputStream in = null;
	BufferedOutputStream out = null;
	try {
		in = new BufferedInputStream(new FileInputStream(fromFileName));
		out = new BufferedOutputStream(new FileOutputStream(toFileName));
		int readContent;
		while((readContent = in.read())!=-1) {
			out.write(readContent);
			out.flush();
		}
	} catch (FileNotFoundException e) {
		e.printStackTrace();
	} catch (IOException e) {
		e.printStackTrace();
	}finally {
		try {
			if(in!=null)in.close();
			if(out!=null)out.close();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
	long endTime = System.currentTimeMillis();
	long spendTime = endTime - startTime;
	System.out.println("方法三，使用BufferedInputStream和BufferedOutputStream后复制用时："+ spendTime + "毫秒");
}

/**
 * 方法四
 * 方法四，在BufferedInputStream和BufferedOutputStream基础上再次添加缓存数组
 * 方法四，BufferedInputStream和BufferedOutputStream基础上添加缓存数组后复制用时：16毫秒
 * @param fromFileName
 * @param toFileName
 */
public static void bufferedCopyMethod2(String fromFileName,String toFileName ) {
	long startTime = System.currentTimeMillis();
	BufferedInputStream in = null;
	BufferedOutputStream out = null;
	try {
		in = new BufferedInputStream(new FileInputStream(fromFileName));
		out = new BufferedOutputStream(new FileOutputStream(toFileName));
		int readContent ;
		byte[] buf = new byte[1024];
		while((readContent=in.read(buf))!=-1) {
			out.write(buf);
			out.flush();
		}
	} catch (FileNotFoundException e) {
		e.printStackTrace();
	} catch (IOException e) {
		e.printStackTrace();
	}finally {
		try {
			if(in!=null)in.close();
			if(out!=null)out.close();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
	long endTime = System.currentTimeMillis();
	long spendTime = endTime - startTime;
	System.out.println("方法四，BufferedInputStream和BufferedOutputStream基础上添加缓存数组后复制用时："+ spendTime + "毫秒");
}


public static void main(String[] args) {
	String fromFileName = "C:\\Users\\Administrator\\Desktop\\test.wmv";
	String toFileName = "C:\\Users\\Administrator\\Desktop\\test1.wmv";
	//baseCopyMethod(fromFileName,toFileName);
	//baseCopyMethod2(fromFileName,toFileName);
	//bufferedCopyMethod(fromFileName,toFileName);
	bufferedCopyMethod(fromFileName,toFileName);
}

}