java复制单个文件代码~

  
    

   
     
   
      1 
   
     import
   
      java.io.File;

   
      2 
   
      
   
     import
   
      java.io.FileInputStream;

   
      3 
   
     
   
     import
   
      java.io.FileOutputStream;

   
      4 
   
     
   
     import
   
      java.io.InputStream;

   
      5 
   
     

   
      6 
   
     

   
      7 
   
     
   
     public
   
      
   
     class
   
      FileCopy {

   
      8 
   
      
   
     public
   
      
   
     static
   
      
   
     void
   
      main(String[] args)

   
      9 
   
      {

   
     10 
   
      
   
     try
   
     

   
     11 
   
      {

   
     12 
   
      
   
     int
   
      bytesum 
   
     =
   
      
   
     0
   
     ;

   
     13 
   
      
   
     int
   
      byteread 
   
     =
   
      
   
     0
   
     ;

   
     14 
   
      File oldfile 
   
     =
   
      
   
     new
   
      File( 
   
     "
   
     c:/test.txt
   
     "
   
     );

   
     15 
   
      
   
     if
   
      ( oldfile.exists() )

   
     16 
   
      { 
   
     //
   
     文件存在时
   
     

   
     17 
   
     
   
      InputStream inStream 
   
     =
   
      
   
     new
   
      FileInputStream( 
   
     "
   
     c:/test.txt
   
     "
   
      ); 
   
     //
   
     读入原文件
   
     

   
     18 
   
     
   
      FileOutputStream fs 
   
     =
   
      
   
     new
   
      FileOutputStream( 
   
     "
   
     d:/test.txt
   
     "
   
      );

   
     19 
   
      
   
     byte
   
     [] buffer 
   
     =
   
      
   
     new
   
      
   
     byte
   
     [ 
   
     1444
   
      ];

   
     20 
   
      
   
     int
   
      length;

   
     21 
   
      
   
     while
   
      ( ( byteread 
   
     =
   
      inStream.read( buffer ) ) 
   
     !=
   
      
   
     -
   
     1
   
      )

   
     22 
   
      {

   
     23 
   
      bytesum 
   
     +=
   
      byteread; 
   
     //
   
     字节数 文件大小
   
     

   
     24 
   
     
   
      System.out.println( bytesum );

   
     25 
   
      fs.write( buffer, 
   
     0
   
     , byteread );

   
     26 
   
      }

   
     27 
   
      inStream.close();

   
     28 
   
      }

   
     29 
   
      }

   
     30 
   
      
   
     catch
   
      ( Exception e )

   
     31 
   
      {

   
     32 
   
      System.out.println( 
   
     "
   
     复制单个文件操作出错
   
     "
   
      );

   
     33 
   
      e.printStackTrace();

   
     34 
   
     

   
     35 
   
      }

   
     36 
   
      }

   
     37 
   
     }

   
     38