createObject() is used to create instances of classes. Now these can be
ColdFusion components, Java classes, CORBA objects and web services. In the
example I showed you I am creating an instance of the java.lang.String class
this is a native class of Java. In Java all Strings are actually objects with
methods. So the if I had just done <cfset bar = createObject("java",
"java.lang.String").init(foo)> that calls the constructor of the String class
and creates a String object with the content of foo. But in this instance I
suggested <cfset bar = createObject("java",
"java.lang.String").init(foo).split("\n")> now this creates the object and
calls the split() method. This method takes an Regex argument and then returns
an array that is split on the regex you passed "\n" is Regex for a new line so
it will create an array containing each row of your text file. Looping through
arrays in ColdFusion MX onwards are majorly faster than lists.
I hope that clears it up.