SRV.5.4 Request Path Elements

SRV.5.4 Request Path Elements

The request path that leads to a servlet servicing a request is composed of many important sections. The following elements are obtained from the request URI path and exposed via the request object:

• Context path: The path prefix associated with the ServletContext that this servlet is a part of. If this context is the "default" context rooted at the base of the web server's URL namespace, this path will be an empty string. Otherwise, this path starts with a '/' character but does not end with a '/' character.

• Servlet path: The path section that directly corresponds to the mapping which activated this request. This path starts with a '/' character.

• Path info : The part of the request path that is not part of the context path or the servlet path.

The following methods exist in the HttpServletRequest interface to access this information:

• getContextPath

• getServletPath

• getPathInfo

It is important to note that, except for URL encoding differences between the request URI and the path parts , the following equation is always true:

 requestURI = contextPath + servletPath + pathInfo 

To give a few examples to clarify the above points, consider Table SRV.5-1.

Table SRV.5-1. Example Context Setup

Context Path	/catalog
Servlet Mapping	Pattern: /lawn Servlet: LawnServlet
Servlet Mapping	Pattern: /garden Servlet: GardenServlet
Servlet Mapping	Pattern: *.jsp Servlet: JSPServlet

The behavior in Table SRV.5-2 is observed .

Table SRV.5-2. Observed Path Element Behavior

Request Path	Path Elements
/catalog/lawn/index.html	ContextPath: /catalog ServletPath: /lawn PathInfo: /index.html
/catalog/garden/implements/	ContextPath: /catalog ServletPath: /garden PathInfo: /implements/
/catalog/help/feedback.jsp	ContextPath: /catalog ServletPath: /help/feedback.jsp PathInfo: null