The request object breaks down the request URL into components. Servlets and JSP pages can use those components to vary the response while using the same servlet or JSP page.

Some reasons you may need to look at the URL information:

• form submission
• selecting sections of a manual
• displaying different stories on a news site
• displaying comments on a discussion group
• sort preferences for the discussion site
• search results

RequestURI

getRequestURI() returns the full path, excluding any query string.

ServletPath

getServletPath() returns the URI prefix that matches the servlet. In the case of a JSP, it will return everything up to the *.jsp.

The servlet path is useful for servlets like JSP, XTP, or SSI that read and transform files.

PathInfo

getPathInfo() returns everything after the ServletPath.

A discussion board servlet could use PathInfo to select stories and comments.

QueryString

getQueryString() returns the query string, everything after the '?'

Often, query strings are the result of form submissions but it's also useful for database-driven sites. For example, you might encode "story 15, comment 7" of a discussion as /comment.xtp?story=15&comment=7.

http://localhost:8080/test/env.jsp/tail?a=b

env.jsp

<table> <tr><td>URI <td><%= request.getRequestURI() %> <tr><td>ServletPath <td><%= request.getServletPath() %> <tr><td>PathInfo <td><%= request.getPathInfo() %> <tr><td>QueryString <td><%= request.getQueryString() %> <tr><td>a <td><%= request.getParameter("a") %> </table>

URI /test/env.jsp/tail ServletPath /test/env.jsp PathInfo /tail QueryString a=b a b

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