Excessive Barking When Not Home

Question
I have a 2.5 year old male boxer.  Recently i received a complaint from my apartment complex that he is barking excessively while i am not home.  I have to keep him in his crate when i leave for my classes because he will soil all over the house due to his anxiety.  In the crate he will not soil at all.  When i leave the house and put him in, he does not like it but does not cry or bark.  Also, when i return i do not hear barking upon my arrival.  However, i am being told he is baring while i am not there.  They have threatened to evict me if i cannot rectify the situation within 10 days.

I don't know what to do, he is fine while i am home, no barking.  How can i train him to not bark when i am gone if no one is there to reprimand him for this behavior.  I refuse to get rid of my dog, but i do not want to be evicted.  He has a deep, loud bark and i am sure it is not pleasant to hear at 7 in the morning when i leave.

Another expert responded telling me he needed more exercise, she went away on vacation before i could do a follow up. I was going to say that he does get a lot of exercise.  I take him to the dog park between 5-6 days a week, each time staying at least 2 hours so he can run around and play with the other dogs, which he does the whole time.  Can he need more exercise than this??

Answer
Lindsay,
It does sound like he is getting plenty of exercise, but each dog is different.  Maybe try taking him for a long walk right before you leave if that is possible.  Just something to tire him out in hopes that he will sleep during the day.   
Is it possible to gate him in the kitchen which I assume has a floor that would be easy to clean up if he had an accident.   Not sure if he is the type to open cabinets, get into things etc.   So, if so- -- definitely not an option.
Try getting a sterilized bone from your local petstore.  I've found that dogs will chew on them for hours on end and it tires them out and keeps them occupied.   Also, your boy could be barking at noises outside of the apartment.   Try keeping the radio or TV on for him.  Not only will it keep him company, it will help to drown out outside noises.