import java.io.*;

public class CopyFile {

    public static void main(String[] args){

        String srcPath = "/opt/a.txt";

        String outPath = "/opt/b.txt";

        inputStreamOutputStream(srcPath,outPath);

    }

    /***

 *      *

 *           * @param src 源文件

 *                * @param out 目标文件

 *                     */

    public static void inputStreamOutputStream(String src,String out){

        FileInputStream fileInputStream = null;

        FileOutputStream fileOutPutStream = null;

        try{

            fileInputStream = new FileInputStream(src);

            fileOutPutStream = new FileOutputStream(out);

            byte[] bytes = new byte[1024];

            int num = 0;

            while((num = fileInputStream.read(bytes)) != -1){

                System.out.println(num);

                fileOutPutStream.write(bytes,0,num);

            }

        }catch(IOException e){

            e.printStackTrace();

        }finally {

            try { 

                fileOutPutStream.close();

                fileInputStream.close();

            } catch (IOException e) {

                e.printStackTrace();

            }

        }

    }

}