Welcome aboard, Arthur,
I'm sorry to tell you that coffee makers are one of the
prohibited items with Disney Cruise Line. The good news, however, is that there is always coffee available, all day and night. Besides the restaurants which serve coffee, there is also a 24-hour beverage station on the pool deck where you can help yourself to coffee and 24-hour room service is complimentary, so feel free to order coffee from them whenever you'd like as well. (Just be sure to have a couple of dollars which is customary to tip the Cast Member who delivers your room service.)
If you're very particular about your coffee and find that you're not a big fan of the coffee around the ship, you have another great option:
Cove Cafe. This adult exclusive cafe is in the Quiet Cove pool area, and it's a great place to relax with a specialty coffee drink. There is an additional cost for these specialty drinks, but they are delicious, Arthur, so swing by there to take a look at the menu.
I hope those details help as you continue planning for your cruise. Please stop back if you have any other questions before you set sail! I'm happy to help!