How do I get my spring rolls crispy?

As Brendon mentioned, the oil needs to be very hot. Just test this by dropping a cube of bread into the oil. If it 'sizzles' and starts to colour, the oil is hot enough. Also, cook the spring rolls in small batches, say 2 or 3 at a time. Overloading the pan or wok won't help.

If you don't have a fry thermometer -- the important part of frying is the bubbles coming off the food in the oil. If you don't have bubbles, the oil's too cold. The trick I use for measuring the temperature (as I don't have a fry thermometer) is to dip the end of a wooden spoon into the oil -- the wood holds enough moisture that if the oil's hot enough, it should bubble.

As you're adding food, if the bubbles lessen, you're cooling the oil off too much, and need to adjust the heat to compensate.

Was the oil hot when you added them? To get something crispy and not soggy, the oil needs to start out hot.

Trust me, my aunty makes homemade spring rolls for a living - Freeze them and fry them from frozen. And Control the heat so that when you add them at the start, it's hot enough that the oil is bubbling and they are crisping up, don't have the oil too low that they're just Soaking up the oil, but also not too hot that they're browning too quickly or burning, because they need to have time to cook properly on the inside aswell. Lower the heat if you need to. If they are browning too quickly you can take them off the heat completely until they settle down a bit, sometimes if the oil is too hot, even putting it on the lowest setting wont stop then from burning. But of course it's better to not let the oil get too hot in the first place :)

P. S If they stick together after frozen, put them in a plastic bag and lay something like a thick newspaper or rug on the floor (to protect your floor) and mildly bang or drop the frozen spring rolls on the floor until they seperate. And If you're filling is too thick and you're worried they won't cook through, I guees you could freeze them partially so the inside isn't too frozen. Hope that helps :)

1. The Filling

Consideration has to be taken into account on moisture content, size/thickness of the pieces and whether they need prior cooking and/or draining. All the ingredients should cook at the same time, or not require cooking.

2. The Wrapper (and wrapping)

Presuming the wrapper is the defrosted conventional Chinese wrapper (flour, water, oil) specifically made for Spring Rolls. Make sure you roll it tight and firm (a loose roll will allow oil to flood in, and seal the final end with ideally a flour paste, but egg wash would work.

3. Batter (or no batter)?

Depending on your desired look of your Spring Roll, and when you will serve them (ie immediately after frying, or later as in party or reheat before serving) will help you decide about Batter. Non battered spring rolls don't reheat well, especially in the fryer.

4. Frying

The type of oil, quantity and the temperature of the oil is important. You need a high smoking/burning point and enough volume of oil to keep the temperature from dropping as you add your spring roll/s. The temperature will depend on the size (length and thickness) and whether the filling needs to be cooked. Your spring roll/s should sizzle as they enter the oil and bubble away. Don't overload your fryer, your spring rolls will start soaking up the oil and possibly start to unravel. You might also want to check your fryer, a deeper pan would be better then a shallow pan - spring rolls are usually heavy at the start and sink down. When they float or when they stop bubbling much is a sign they are done.

5. Draining

Depending if you had wet ingredients you might need to make a small prick in two ends and stack them on their ends to drain any excess oil or liquid. Also your spring rolls should be spaced out from each other as they drain, this reduces them absorbing moisture from each other.

Hopefully yours turns out better!