I am/was in the same situation as you (just about a year ahead). The place I currently work at (also software, requiring a 4 year degree, and a small company). I replied around the beginning of my last semester for an Entry-level position.
Something to note is that what you actually know is a lot more powerful than the sheet of paper your school gave you says you know. Personal projects do wonders in showing what you know and that you have motivation to go beyond schooling and look good on a student's resume (assuming you don't have tons of work experience with software at the moment).
You'll never get punished for trying to get your foot in the door. Even if they don't agree to hire you, they might just encourage you to apply when you're graduated.
Another thing to note: If they are consciously aware that you are just graduating and will be entry level, it might be a good idea to elaborate on the wide range of topics (related) that you're knowledgeable about. You might not be a pro, but that's good! It means you'll be bringing a fresh mind to the company!