question: public static void appendFileToFile ( final File file1 , final File file2 ) { if ( ! isReadable ( file1 ) || ! isReadable ( file2 ) || ! isWritable ( file1 ) ) { return ; } try { FileInputStream inputStream = new FileInputStream ( file2 ) ; FileOutputStream outputStream = new FileOutputStream ( file1 , true ) ; int count ; final int buffer_size = 4096 ; byte [ ] bytes = new byte [ buffer_size ] ; while ( ( count = inputStream . read ( bytes , 0 , buffer_size ) ) > 0 ) outputStream . write ( bytes , 0 , count ) ; FileUtils . sync ( outputStream ) ; outputStream . close ( ) ; inputStream . close ( ) ; } catch ( FileNotFoundException e ) { e . printStackTrace ( ) ; } catch ( IOException e ) { e . printStackTrace ( ) ; } }
target:  Appends one file to another.