Finding the longest word (Java)

HI again

I'm a bit new to Java programming and was wondering how i would find the longest word. (In this context a word is taken to mean any sequence of characters which does not contain a space).

So, if a string object had the following state :

This is a test_string (to illustrate) a line containing several words.

The state of the string object is created from the contents of a file.

I'm absolutely stumped as to how to create the code for this

 

i take it that is a no