Core Servlets and JavaServer Pages™

3.2. Reading Form Data from Servlets

One of the nice features of servlets is that all of this form parsing is handled automatically. You simply call the getParameter method of the HttpServletRequest, supplying the case-sensitive parameter name as an argument. You use getParameter exactly the same way when the data is sent by GET as you do when it is sent by POST. The servlet knows which request method was used and automatically does the right thing behind the scenes. The return value is a String corresponding to the URL-decoded value of the first occurrence of that parameter name. An empty String is returned if the parameter exists but has no value, and null is returned if there was no such parameter. If the parameter could potentially have more ...