I have a set of files in particular diretory.

After retrieving the contents from all the files(text files) in the directory, I have a 
List of Strings.

Each string element represents the retrieved content from each file. So the first String element in the list represents the content from first file.

Now I want to split the string to get words.(Later the words store into an array of strings)
1) words can be seperated by single space/multiple space.
2) Sentences are end by a '.', so a new word can be started after '.'
3) A new word can start after '\n'

So can anyone suggest a regular expression which can fit into split() method?