The ByteEncoder class assumes that if a value isArray(), the array type is Object. This throws a ClassCastException if you attempt to pass a primitive array:

else if ( val.getClass().isArray() )
putList( name , Arrays.asList( (Object[])val ) );

It would be more flexible to use Array.get() to reflectively read the array:

private void putArray( String name , Object array )

{ _put( ARRAY , name ); final int sizePos = _buf.position(); _buf.putInt( 0 ); int size = Array.getLength(array); for ( int i=0; i<size; i++ ) _putObjectField( String.valueOf( i ) , Array.get( array, i ) ); _buf.put( EOO ); _buf.putInt( sizePos , _buf.position() - sizePos ); }

I can provide a patch, if needed.