Loading an XML file into a String Variable

I am required to send XML data to a locally running java client in the following format:

http://localhost:5000/?xml= "XML GOES HERE"

Is it possible to load an XML file into a string variable and then use an HttpWebRequest to execute the query?

I have tried using a StreamReader on the XML file but it doesnt seem like the best way and I think its omitting the xml tags.

Any suggestions would be very helpful.
Tom