I moved your question out of the main competition thread so we could have some discussion about it on the side. Once you have it working and are happy with it then you are more than welcome to submit your new solution to the competition thread again.
Now, back to your question:
You are so very close. Observe that the tests are inspecting the data being returned from the wordOccurrence method, they are not inspecting what is being output with System.out.println. So have a think about what you need to do with wordMap at the end of the method.