Java实现将一个文件的复制到另一个文件中去（字节流形式...可复制文本，视频，音频等文件）

实现代码如下

package FileRead;

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;

public class Test {
    public static void main(String[] args) throws IOException {
        FileInputStream fileInputStream = new FileInputStream("D:\\file.mp4");
        FileOutputStream fileOutputStream = new FileOutputStream("D:\\myFile\\file.mp4");//使用时必须先创建文件夹myfile
        int b;
        while ((b = fileInputStream.read()) != -1){
            fileOutputStream.write(b);
        }

        fileInputStream.close();
        fileOutputStream.close();
    }
}

上述的实现代码只能对小型文件进行复制，但是像音频或者视频的话，一般文件较大，复制消耗的时间相当大，所以有了下面的改进版

package FileRead;

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;

public class Test {
    public static void main(String[] args) throws IOException {
//        FileInputStream fileInputStream = new FileInputStream("D:\\file.mp4");
//        FileOutputStream fileOutputStream = new FileOutputStream("D:\\myFile\\file.mp4");
//        int b;
//        while ((b = fileInputStream.read()) != -1){
//            fileOutputStream.write(b);
//        }
//
//        fileInputStream.close();
//        fileOutputStream.close();


        FileInputStream fileInputStream = new FileInputStream("D:\\file.mp4");
        FileOutputStream fileOutputStream = new FileOutputStream("D:\\myFile\\file.mp4");
        byte btye[] = new byte[1024];
        int len;
        while ((len = fileInputStream.read(btye)) != -1){
            fileOutputStream.write(btye,0,len);
        }

        fileInputStream.close();
        fileOutputStream.close();


    }
}