Simon Brown's Blog: Comparing webapp frameworks : Model 1 with JSP XML

My pages	Projects	Communities	java.net

Get Involved

java-net Project

Request a Project

Project Help Wanted Ads

Publicize your Project

Get Informed

java.net Online Books

java.net Archives

Get Connected

java.net Forums

Wiki and Javapedia

People, Partners, and Jobs

Java User Groups

RSS Feeds

Search

Online Books:

Advanced Search

Simon Brown's Blog

«Comparing webapp frameworks : Model 1 with JSTL | Main | Comparing webapp frameworks : Struts »

Comparing webapp frameworks : Model 1 with JSP XML

Posted by simongbrown on January 12, 2006 at 02:49 AM | Comments (0)

For completeness, I wanted to show how the JSP pages from the JSTL version could be written using the JSP XML syntax. Unsurprisingly, many people don't even know of its existence and, as I've blogged before, there aren't that many situations where you'd want to use it to write pages by hand. Should you need to, here are a couple of examples of how you would go about it using the XML syntax.

Home page
Here's the home page once again, implemented using the JSTL and written in the JSP XML syntax.

<?xml version="1.0" encoding="UTF-8"?>
<jsp:root xmlns="http://www.w3.org/1999/xhtml"
   xmlns:jsp="http://java.sun.com/JSP/Page"
   xmlns:c="http://java.sun.com/jstl/core_rt"
   xmlns:fmt="http://java.sun.com/jstl/fmt_rt"
   version="2.0">

  <jsp:useBean id="blogService" scope="request" class="domain.BlogService"/>
  <c:set var="blog" value="${blogService.blog}" />

  <jsp:output doctype-root-element="html"
    doctype-public="-//W3C//DTD XHTML 1.0 Transitional//EN"
    doctype-system="http://www.w3c.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"/>
  <jsp:directive.page contentType="text/html;charset=UTF-8" />

  <html xmlns="http://www.w3.org/1999/xhtml">

    <head>
      <title>${blog.name}</title>
      <link rel="stylesheet" href="screen.css" type="text/css" />
    </head>

    <body>
      <div id="container">
        <h1>${blog.name}</h1>
        <h2>${blog.description}</h2>

        <c:forEach var="blogEntry" items="${blog.blogEntries}">
          <div class="blogEntry">
            <h3>${blogEntry.title}</h3>

            <c:choose>
              <c:when test="${not empty blogEntry.excerpt}">
                ${blogEntry.excerpt}
                <p>
                <a href="viewBlogEntry.jsp?id=${blogEntry.id}">Read more</a>
                </p>
              </c:when>
              <c:otherwise>
                ${blogEntry.body}
              </c:otherwise>
            </c:choose>

            <p>
            Posted on <fmt:formatDate value="${blogEntry.date}"
                        timeZone="${blog.timeZone}" type="both"
                        dateStyle="long" timeStyle="long" />
            </p>
          </div>
        </c:forEach>
      </div>
    </body>

  </html>

</jsp:root>

In comparison to the previous implementation, the major difference here is that the JSP page must be well formed XML, with everything wrapped up inside a <jsp:root> element. In addition, the taglib directives are replaced by a simple XML namespace, which is really quite neat.

Blog entry detail page
The blog entry detail page is fairly similar in all respects, with the Java code at the top of the page now being wrapped up inside a <jsp:scriptlet> element.

<?xml version="1.0" encoding="UTF-8"?>
<jsp:root xmlns="http://www.w3.org/1999/xhtml"
   xmlns:jsp="http://java.sun.com/JSP/Page"
   xmlns:c="http://java.sun.com/jstl/core_rt"
   xmlns:fmt="http://java.sun.com/jstl/fmt_rt"
   version="2.0">

  <jsp:output doctype-root-element="html"
    doctype-public="-//W3C//DTD XHTML 1.0 Transitional//EN"
    doctype-system="http://www.w3c.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"/>
  <jsp:directive.page contentType="text/html;charset=UTF-8" />
  <jsp:directive.page import="domain.*" />

  <jsp:scriptlet>
    BlogService blogService = new BlogService();
    Blog blog = blogService.getBlog();
    request.setAttribute("blog", blog);

    BlogEntry blogEntry = blog.getBlogEntry(request.getParameter("id"));
    if (blogEntry == null) {
      response.sendError(HttpServletResponse.SC_NOT_FOUND);
      return;
    } else {
      request.setAttribute("blogEntry", blogEntry);
    }
  </jsp:scriptlet>

  <html xmlns="http://www.w3.org/1999/xhtml">

    <head>
      <title>${blogEntry.title} : ${blog.name}</title>
      <link rel="stylesheet" href="screen.css" type="text/css" />
    </head>

    <body>
      <div id="container">
        <h1>${blog.name}</h1>
        <h2>${blog.description}</h2>

        <div class="blogEntry">
          <h3>${blogEntry.title}</h3>

          ${blogEntry.body}

          <p>
          Posted on <fmt:formatDate value="${blogEntry.date}"
                      timeZone="${blog.timeZone}" type="both"
                      dateStyle="long" timeStyle="long" />
          </p>
        </div>
      </div>
    </body>

  </html>

</jsp:root>

Summary
All in all, there aren't massive changes between writing a page in the native JSP syntax and writing it in the XML syntax, but care does have to be taken to ensure that your JSP pages are valid XML and easily readable if using the latter. Personally, I've never seen the XML syntax in use on projects that I've been involved with but the choice, as they say, is yours.

Right, let's put model 1 behind us and start comparing some webapp frameworks. :-)

Bookmark blog post: