I just played a match of SF4 against a player who ONLY spammed hadokens. I really don't see this much, but this isn't the first time I've encountered players that play like this. I mean, I'm just average at SF4, but I feel like this strategy is absolutely ridiculous. All you can do is jump/FAD through them, but it gets to a point where it just becomes overwhelming when the missile spam spans for entire matches. To make matters worse, every time I actually got close enough, I get a few hits in and am promptly L-HK'd until he gets enough distance to continue the spam. I'm guessing the best way around this is to keep pressure on the other player, but it's really hard to do when said other player has such an obscene play style. Any more seasoned players know a way around this strategy? Or is it as hard as I think to win against it? 
 
 (Btw, I'm going to play some SF4 right now so add me if you want to play a few matches. GT is xATHFxMrBubbles.)

I just played a match of SF4 against a player who ONLY spammed hadokens. I really don't see this much, but this isn't the first time I've encountered players that play like this. I mean, I'm just average at SF4, but I feel like this strategy is absolutely ridiculous. All you can do is jump/FAD through them, but it gets to a point where it just becomes overwhelming when the missile spam spans for entire matches. To make matters worse, every time I actually got close enough, I get a few hits in and am promptly L-HK'd until he gets enough distance to continue the spam. I'm guessing the best way around this is to keep pressure on the other player, but it's really hard to do when said other player has such an obscene play style. Any more seasoned players know a way around this strategy? Or is it as hard as I think to win against it? 
 
 (Btw, I'm going to play some SF4 right now so add me if you want to play a few matches. GT is xATHFxMrBubbles.)

Yeah, fireball spam can be a good stratergy but it is very flawed. There are alot of ways to get around fireballs in this game unlike in the old days of SFII like hurricane kicks, wall dives, ex fireballs, ultras ect.
 
Also I'll play some :).

Ok I figured out why you're having a hard time.
 
You mash ultra when someone's attacking you.
You mash all kinds of SRK on wakeup.
You mash all kinds of SRK when someone's attacking you.
You Ultra midscreen randomly which is easily countered with a reverse ultra or anything else.
 
That's probably why you're having a hard time.
Good spirit though and at least you end a fight with a wink which is very important to me.

"Ok I figured out why you're having a hard time.  You mash ultra when someone's attacking you. You mash all kinds of SRK on wakeup. You mash all kinds of SRK when someone's attacking you. You Ultra midscreen randomly which is easily countered with a reverse ultra or anything else.  That's probably why you're having a hard time. Good spirit though and at least you end a fight with a wink which is very important to me. "

 @Noodlearms: By itself, it isn't really a good strategy.  It is used mainly for zoning(keeping your opponent where you want them) and a little bit of damage.  You have to know proper anti-airs/punish combos for when your opponent gets in.  
Honestly it seems like you just don't have a lot of time in the game yet.  The game probably seems really hectic and fast-paced right now.  Keep playing and the game will slow down and fireballs will not even bother you anymore.  
 Use @Scooper's advice and keep practicing and mostly, just have fun. 

We all get plastered by a good zoning player now and then.  However, once you have some more time in the game you'll be able to show mediocre zone players that you can break it down quickly and get in their face (most the time).  A combination of focusing through fireballs, using whatever tools your character has to get through them in other ways, and punishing them for making a mistake in their zoning really deters them in the later rounds.  Its a tool that not many people use correctly online, but it can be really good if they play the mind game pretty well.

If you can't detect a pattern to the projectile throwing, it's in your best interest to consider them a good player and respect the space a little more. It is what's called good zoning, and frustrated players usually call it spamming. If he was keeping you out successfully and backing out of danger, I'd say that's good zoning.