Requst object for JSP Study Notes

The request object is an instance of the HttpServletRequest interface, while the parent interface of HttpServletRequest is ServletRequest. However, currently, ServletRequest only has one HTTP ServletRequest interface. If a new Protocol appears in the future, as long as the new protocol inherits ServletRequest, the request object function can be: 1. Receive form parameter: request. getParameter (); in this case, it is important to note that garbled characters may occur when receiving parameters, because the execution process of all static WEB is to first retrieve a page from the server, and then submit the content through this page, after being submitted to the server, the server returns the processing result to the client for display. Therefore, if you want to directly enter the content, you must set the encoding to the same as the encoding of the server content, you can use the setCharacterEncoding () method provided in the ServletRequest interface for unified encoding settings, that is, you can use the request on the receiving page. setCh AracterEncoding ("GBK"); After unified encoding, the form value is received. 2. Form submission method: the form submitted by get and postget will display all the parameters in the address bar, which is insecure. If too much content is submitted, an error will occur, because the URL address bar can only store up to 4 K ~ 5 K content, so the Conference caused the failure to submit a post submission form in the address bar will not display the submission parameters and other content, such submission is safer, and will not be limited by the amount of content, however, if the content is too large, it will exceed the http timeout limit. 3. Use address rewriting to submit the parameter format: Xxx. jsp? Parameter Name = parameter value & parameter name = parameter value [html]