pageContext is an implicit object available in JSPs. The EL documentation says
The context for the JSP page. Provides access to various objects including:
Thus this expression will get the current
HttpServletRequest object and get the context path for the current request and append
/JSPAddress.jsp to it to create a link (that will work even if the context-path this resource is accessed at changes).
The primary purpose of this expression would be to keep your links ‘relative’ to the application context and insulate them from changes to the application path.
For example, if your JSP (named
thisJSP.jsp) is accessed at
http://myhost.com/myWebApp/thisJSP.jsp, thecontext path will be
myWebApp. Thus, the link href generated will be
If someday, you decide to deploy the JSP on another server with the context-path of
corpWebApp, the href generated for the link will automatically change to
/corpWebApp/JSPAddress.jsp without any work on your part.