How to count the frequency of words in textual doent and then sort words(frequency wise) by using Java?

I WANT TO EXTRACT THE MOST FREQUENT WORDS FROM A TEXT FILE.So if there are 200 words a text file and "eat","algorithm" are the words which occurs in the text doent 20 and 15 times RESPECTIVELY,then the output of the program will be those two words,because they are the most frequently used words in the doent.HELP ME WITH THE CODE.PLEASE.PLEASE.PLEASE.