CS651

CS651 | Web Systems

Servlet Equivalents of CGI variables

This page discusses how you retrieve CGI variables should you wish to access. CGI varaibles are in part taken from HTTP request headers, and server and client machine information.
CGI Variable	How to Access in Servlet r = instance of HttpServletRequest
AUTH_TYPE	Gives scheme specified (basic or digest) *r.getAuthType();*
CONTENT_LENGTH	For POST only, gives # bytes of data sent *r.getContentLength()* = returns int, convert to String to get same type as CONTENT_LENGTH
CONTENT_TYPE	MIME type of data being sent. *r.getContentType()*
DOCUMENT_ROOT	Specifies real directory of the URL *r.getRealPath()*
HTTP_XXX_YYY	This describes series of HTTP request header variables like HTTP_COOKIE, HTTP_USER_AGENT, etc. Access either via *r.getHeader("Cookie"), etc. or use direct methods if exis r.getCookies()*. See info on HTTP Request Headers.
PATH_INFO	Specifies path of URL *r.getPathInfo()*
QUERY_STRING	For GET requests, gives query data at the end of the URL *r.getParameter("name") can be used most efficiently to get the parsed value. r.getQueryString()* can be used to get the entire query data string in unparsed format.
REMOTE_ADDR	gives IP address of client making request *r.getRemoteAddr()*
REMOTE_HOST	gives domain name of client *r.getRemoteHost()*
REMOTE_USER	If an Authorization Header (see HTTP request headers) was specified, gives the user part. *r.getRemoteUser()*
REQUEST_METHOD	stipulates HTTP request type, e.g. GET, POST, PUT, DELETE, etc. *r.getMethod()*
SCRIPT_NAME	gives path to servlet *r.getServletPath()*
SERVER_NAME	gives host of server *r.getServerName()*
SERVER_PORT	gives port server on *r.getServerPort()*
SERVER_PROTOCOL	tells protocol and version used on server, (e.g. HTTP/1.1, etc) *r.getProtocol()*
SERVER_SOFTWARE	tells about id of Web-server *getServletContext().getServerInfo()* this is method of HttpServlet class!!!