Friend keeps obsessively texting/fb messaging! How to stop it?!?

[CJ]

This is one of my male friends, that i know has liked me in the past (and may still), but he knows for a fact how i feel about him, and I am NOT into him that way, but even so, he'll text me everyday, every few hours saying hey and asking how I am etc. Even if we meet up in person for lunch, within 10 mins he'll start trying to chat on text as if we hadn't talked in weeks, or within 2 hours, he'll ask me how I am. I respond saying "exactly how i was 2 hours ago" but he doesnt get the hint!!! I often am too busy to respond, and i noticed that he messages me on fb even if im offline, and then he moans when I don't reply for ages.

Below is a snippit of our facebook chat between 4th - 13th of october. My reason for not responding? - i wasnt online at all during that period!!

04/10/2013 10:41
hiya

05/10/2013 08:46
morning

06/10/2013 17:40
herro

08/10/2013 15:10
hi you ok

09/10/2013 14:37
hey

09/10/2013 15:58
you ok

11/10/2013 17:32
hi

12/10/2013 13:35
hi

13/10/2013 16:49
hii

13/10/2013 18:03
how are you#

--

Just this weekend I was at Comic Con. He KNEW I was taking it like a holiday and so wouldn't be responding to any texts/fb etc unless an emergency, and yet he texted and facebook messaged me 10 times over a 3-day-period -_-

It's getting ridiculous. How can I get it to stop?!
Just from today he's put:

5 hours ago
hi

4 hours ago
hiya

2 hours ago
you ok

1 hour ago
good time in london?

2 minutes ago
hi
I don't have a clue how to word it! I just wanna put "dude! i was on holiday! stop messaging me every freakin second!!!!" but im pretty sure that'd upset him -.-
To the people saying 'block him'. I did block him from chat (so he'd always see me as offline) yet he STILL said hi, asked me how i was, what i was up to, did i sleep well etc! how should i go about saying i want him to stop texting as frequently and actually give me some breathing space!?!