Would You Give Up Your Source?

This week I was Posed an interesting question. It all started when my Communications Law class started talking about Media and the Law/ Ethics. Well, being the only broadcasting major in the class I was singled out and as this question: Would you give up your source in a trial if they brought you into a court case? ....
Talk about being caught off guard. Up until now i never gave it much thought. It something you don't think about until you are put in that situation. Well i had to give and answer the professor was waiting on me. My first response was that it depended on the situation. Because I'm not one to rat someone out that has helped me I'm also not the type of person who would let a rapist or terrorist go free. Well, that answer did not go over to well. So I said No. I would not divulge my sources for a trial. The way I see it is this: these people trust me which is why they tell me information. If I loose that trust then I loose my Information. Not only do I suffer but the public will suffer because they will not have the information that i have to give them anymore. So I chose the "don't bite the hand that feeds you" route.
That seemed to please my professor for about a 30 seconds and then she throws at me this ... what if it was between that and going to jail? Well I'll be honest I'm no martyr. I will do the right thing as I see it but even though I still feel that every situation should be handled in its own way is still had to answer. Again this is a lot to decide in a matter of 30 seconds... at least i felt that it was. I was deciding whether to end my career as a reporter (essentially) and possibly get marked by the party which I handed to the police or go to jail. So either way its just not a good situation. Plus, I would say I have pretty god morals. I don't like innocent people going to jail and certainly disapprove of a criminal going free. But if there is one thing that I have learned in life is that sometimes you have to make decisions based on your own personal needs.
In the end of the massive debate in my head I came to one conclusion... I would not let myself go to jail for someone Else's mishap even if I was threatened my by source. After all at least I could have a job and a life.... even if witness protection gave me a new name and place to live.
I came to all of these conclusions but i can't really say if they are right or wrong. In the end who is to say they are or aren't anyways. I started really thinking about them after class and wondering if my answers were something I would stick by. I have decided that they are but again I'll never really know until I've been faced with it. I am also still in school and don't really know exactly what its like to get a story that would have such drama associated with it. So its interesting to see what people would do.... so i pose this question to you.... What would you do if the police came to you and asked you to hand over information regarding your source, would you do it or refrain?