How do you write a full stack trace to the log?

Question

I was catching an exception and trying to write the stack trace to the logs like this:

log.warn(e.getMessage());

But all it said was

Answer 1

In your exception method, the underlying String which contains the message is null.

The above answer, now struck out, still holds, except that e is not null, but the detailMessage private instance variable on the Throwable class is null, which is why e.getMessage() is the String null, but e.toString() (which calls underlying null detailMessage.toString) throws a NullPointerException.