Java的文件字节流FileInputStream/FileOutputStream实例

package day20_IO;

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

/* * 需求：把D：\\test.avi复制到当前目录下的copy.avi中 * * 字节流四种方式复制文件： * 基本字节流一次读写一个字节 :耗时：328004ms * 基本字节流一次读写一个字节数组:耗时：551ms * 高效字节流一次读写一个字节:耗时：2187ms * 高效字节流一次读写一个字节数组:耗时：177ms * */
public class CopyMap4Demo {

    public static void main(String[] args) throws IOException {
        // TODO Auto-generated method stub
        long start=System.currentTimeMillis();
        //method1("D:\\test.avi","copy1.avi");
        //method2("D:\\test.avi","copy2.avi");
        //method3("D:\\test.avi","copy3.avi");
        method4("D:\\test.avi","copy4.avi");
        long end=System.currentTimeMillis();
        System.out.println("RunTime:"+(end-start)+"ms");
    }
    //高效字节流一次读写一个字节数组
        public static void method4(String srcString, String destString) throws IOException {
            // TODO Auto-generated method stub
            //创建对象
            BufferedInputStream bis = new BufferedInputStream(new FileInputStream(srcString));
            BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(destString));

            byte[] bys=new byte[1024];
            int len=0;
            while((len=bis.read(bys))!=-1){
                bos.write(bys, 0, len);
            }

            //释放资源
            bis.close();
            bos.close();
        }
    //高效字节流一次读写一个字节
    public static void method3(String srcString, String destString) throws IOException {
        // TODO Auto-generated method stub
        //创建对象
        BufferedInputStream bis = new BufferedInputStream(new FileInputStream(srcString));
        BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(destString));
        int by=0;
        while((by=bis.read())!=-1){
            bos.write(by);
        }

        //释放资源
        bis.close();
        bos.close();
    }

    //基本字节流一次读写一个字节数组
    public static void method2(String srcString, String destString) throws IOException {
        // TODO Auto-generated method stub
        //创建对象
        FileInputStream fis = new FileInputStream(srcString);
        FileOutputStream fos = new FileOutputStream(destString);

        byte[] bys=new byte[1024];
        int len=0;
        while((len=fis.read(bys))!=-1){
            fos.write(bys, 0, len);
        }

        //释放资源
        fis.close();
        fos.close();

    }
    //基本字节流一次读写一个字节
    public static void method1(String srcString, String destString) throws IOException {
        // TODO Auto-generated method stub
        //创建对象
        FileInputStream fis = new FileInputStream(srcString);
        FileOutputStream fos = new FileOutputStream(destString);

        int by=0;
        while((by=fis.read())!=-1){
            fos.write(by);
        }

        //释放资源
        fis.close();
        fos.close();
    }

}