IO流读写（复制）视频文件练习（java）

Posted 2020-11-11 chenchengchen

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);
    }
}