you just have to set URL, method type (Get or Post) and respective parameters. If your page set cookie then you have to set cookie value. using this class you can get the HTML page of any application in Stream and then convert it to text and use as per your requirement. If you have to get any specific data from the result page then you can also HTML parse the page using HTMLEditorKit class.
Or you could simply use the RequestDispatcher.include method. Although "simply" might not be the best word, because I guess you would have to pass your own ServletResponse object that would let you capture the result (see the javax.servlet.ServletResponseWrapper class). But it still looks a bit simpler than HttpClient to me.