import java.io.*;

class Test

{

    public static void main(String args[]){

        FileInputStream fin =null;

        FileOutputStream fout = null;

        try{

            fin = new FileInputStream("e://d/from.txt");

            fout = new FileOutputStream("e://d/to.txt");

            byte [] arr =new byte[1024];

            while(true){

            int temp = fin.read(arr,0,arr.length);

                if(temp == -1){            //读取到末端返回-1

                break;

                }

            fout.write(arr,0,temp);

            }

        }catch(Exception e){

            System.out.println(e);

        }

        finally{            //关掉流

            try{

                fout.close();

                fin.close();

            }catch(Exception e){

                System.out.println(e);

            }

        }

    }

}