question: public static boolean copyFile ( File file , File copy ) { if ( file == null || copy == null ) throw new NullPointerException ( "File cannot be null" ) ; if ( ! file . isFile ( ) || copy . isDirectory ( ) ) throw new IllegalArgumentException ( "Not a valid file" ) ; FileInputStream fis = null ; FileOutputStream fos = null ; try { fis = new FileInputStream ( file ) ; fos = new FileOutputStream ( copy ) ; int bytes ; byte [ ] packet = new byte [ COPY_PACKET_SIZE ] ; while ( ( bytes = fis . read ( packet , 0 , COPY_PACKET_SIZE ) ) != - 1 ) fos . write ( packet , 0 , bytes ) ; return true ; } catch ( Exception e ) { LOGGER . log ( Level . SEVERE , "Error copying file" , e ) ; return false ; } finally { try { if ( fos != null ) fos . close ( ) ; } catch ( Exception e ) { LOGGER . log ( Level . SEVERE , "Problem closing target stream" , e ) ; } try { if ( fis != null ) fis . close ( ) ; } catch ( Exception e ) { LOGGER . log ( Level . SEVERE , "Problem closing source stream" , e ) ; } } }
target:  Copies source file to the destination file, returns true if the file was successfully copied.