question: public static void writeFully ( FileChannel file , long pos , ByteBuffer src ) { try { int off = 0 ; do { int len = file . write ( src , pos + off ) ; off += len ; } while ( src . remaining ( ) > 0 ) ; } catch ( IOException e ) { throw newIllegalStateException ( ERROR_WRITING_FAILED , "Writing to {0} failed; length {1} at {2}" , file , src . remaining ( ) , pos , e ) ; } }
target:  Write to a file channel.