IO读写（复制）视频练习

Posted 2020-11-11

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);
  }
  }