import java.io.*;

public class CopyFile {

    public static void main(String[] args) {

        //1、创建源

        File in = new File("d:/test/1111.mp4");

        File out = new File("d:/test/222.mp4");

        //2、选择流

        InputStream is = null;

        OutputStream os = null;

        try {

            //3、操作数据

            is = new FileInputStream(in);

            os = new FileOutputStream(out);

            byte[] buf = new byte[1024*1024];

            int length = -1;//记录实际读取到的长度

            while ((length = is.read(buf)) != -1) {

                os.write(buf, 0, length);

            }

            os.flush();

        } catch (FileNotFoundException e) {

            e.printStackTrace();

        } catch (IOException e) {

            e.printStackTrace();

        } finally {//4、关闭流（先打开的后关闭）

            try {

                if (os != null)

                    os.close();

            } catch (IOException e) {

                e.printStackTrace();

            }

            try {

                if (is != null)

                    is.close();

            } catch (IOException e) {

                e.printStackTrace();

            }

        }

    }

}