[EMAIL PROTECTED] wrote:
> I've written a configurable ServletInvokerPortlet that invokes
> servlets/JSPs.
> (It uses the workaround for embedding JSPs in ECS trees recently posted
> by Christian Sell, see EcsServletElement.)
>
> Maybe this is useful for others as well:
>
> The URL of the servlet to be invoked can be set by specifying a parameter
> named "url" in the portlet entry in the portlet registry section in the
> file "jetspeed-config.jcfg":
>
> ---- snip ----
> <portlet-entry type="abstract" name="ServletInvokerPortlet">
>
> <classname>org.apache.jetspeed.portal.portlets.ServletInvokerPortlet</classname>
> </portlet-entry>
>
> <portlet-entry type="ref" parent="ServletInvokerPortlet"
> name="RequestInfoPortlet">
> <parameter name="url" value="/RequestInfo/"/>
> <meta-info>
> <title>Request Info</title>
> <description>This portlet shows some request info.</description>
> </meta-info>
> </portlet-entry>
> ---- snap ----
>
> The example defines a portlet named "RequestInfoPortlet" that invokes a
> servlet
> accessible under the URL "/RequestInfo/" whenever it is displayed.
>
> The entry in default.psml or a personal psml file may look like this:
> ...
> <entry type="ref" parent="RequestInfoPortlet">
> <layout position="1"/>
> </entry>
> ...
>
> This is the source for the ServletInvokerPortlet:
>
> ---- snip ----
> package org.apache.jetspeed.portal.portlets;
>
> import org.apache.ecs.ConcreteElement;
> import org.apache.ecs.ElementContainer;
> import org.apache.ecs.StringElement;
>
> import org.apache.jetspeed.portal.*;
> import org.apache.jetspeed.util.*;
>
> import org.apache.turbine.util.*;
>
> import org.apache.jetspeed.portal.portlets.AbstractPortlet;
> import org.apache.jetspeed.util.servlet.EcsServletElement;
>
> /**
> * The ServletInvokerPortlet invokes a servlet or JSP and displays the
> result.
> *
> * @author Thomas Schaeck ([EMAIL PROTECTED])
> */
> public class ServletInvokerPortlet extends AbstractPortlet {
>
> /**
> * Returns an ECS concrete element that includes the servlet/JSP.
> *
> * The servlet/JSP will be invoked when the ECS tree is written
> * to the servlet output stream and add its output to the stream.
> */
> public ConcreteElement getContent() {
> // ------------------------------------------------------------------
> // Note: Rundata should not be obtained from the portlet config,
> // but I found no other way to get it in the current JetSpeed version
> // (as of 10/30/200). Normally, this should be per-request info, not
> // per-portlet config info. If a new request comes in before this code
> // is reached and the rundata in the portlet config is overwritten,
> // we might get the wrong request here.
> // ------------------------------------------------------------------
> RunData rundata = this.getPortletConfig().getRunData();
> PortletConfig pc = this.getPortletConfig();
>
> String servletURL = null;
> try {
> servletURL = (String)
> this.getPortletConfig().getInitParameter("url");
> return new EcsServletElement(rundata, servletURL);
> } catch (Exception e) {
> String message = "ServletInvokerPortlet: Error invoking "
> + servletURL + ": " + e.getMessage();
> Log.error(message, e);
> return new StringElement(message);
> }
> }
> }
> ---- snap ----
>
> Here is a modified version of the code originally posted by Christian Sell.
>
> ---- snip ----
> package org.apache.jetspeed.util.servlet;
>
> import java.io.IOException;
> import java.io.OutputStream;
> import java.io.PrintWriter;
> import java.io.OutputStreamWriter;
> import javax.servlet.*;
>
> import org.apache.turbine.util.RunData;
> import org.apache.turbine.util.Log;
> import org.apache.ecs.ConcreteElement;
> import org.apache.ecs.Element;
>
> /**
> * EcsServletElement encapsulates a servlet/JSP within the context of ECS
> * HTML-generation.
> *
> * This is a workaround to allow invoking servlets from JetSpeed Portlets.
> * The servlet will be invoked when traversal of an ECS tree during writing
> * reaches the EcsServlet element.
> *
> * This is a modified version of Christian Sell's original code.
> */
> public class EcsServletElement extends ConcreteElement
> {
> /** RunData object to obtain HttpServletRequest/Response from. */
> private RunData rundata;
>
> /** URL of servlet to include */
> private String url;
>
> /**
> * Construct an ECS element from a given rundata object and URL.
> *
> * @param rundata Rundata object that holds the
> HttpServletRequest/Response
> * objects to be used for servlet invocation.
> * @param url The URL of the servlet to invoke.
> */
> public EcsServletElement(RunData rundata, String urlString) {
> this.url = urlString;
> this.rundata = rundata;
> }
>
> public void output(OutputStream out) {
> output(new PrintWriter(out));
> }
>
> /**
> * Add element to the designated PrintWriter.
> */
> public void output(PrintWriter out) {
> ServletContext ctx = rundata.getServletContext();
> RequestDispatcher dispatcher = ctx.getRequestDispatcher(url);
> try {
> // Include the servlet or JSP.
> dispatcher.include(rundata.getRequest(),rundata.getResponse());
> } catch (Exception e) {
> String message = "JSPPortlet: Could not include the following URL:
> "
> + url + " : " + e.getMessage();
> Log.error( message, e );
> out.print(message);
> }
> }
> }
> ---- snap ----
>
> This is the example servlet I used. It prints some of the request info in a
> table.
>
> ---- snip ----
> import java.io.*;
> import java.util.*;
>
> import javax.servlet.*;
> import javax.servlet.http.*;
>
> /**
> * This example servlet returns some information about the incoming
> request.
> *
> * @author Thomas Schaeck ([EMAIL PROTECTED])
> */
> public class RequestInfoServlet extends HttpServlet
> {
> public void doGet (HttpServletRequest req, HttpServletResponse res)
> throws ServletException, IOException {
> PrintWriter out;
>
> res.setContentType("text/html");
> out = res.getWriter ();
>
> out.println("<HTML><HEAD><TITLE>Example Servlet</TITLE>" +
> "</HEAD><BODY BGCOLOR=\"#FFFFEE\">");
> out.println("<h4>Request Information:</h4>");
> out.println("<TABLE Border=\"2\" WIDTH=\"65%\" BGCOLOR=\"#DDDDFF\">");
> out.println("<tr><td>Remote user</td><td>" + req.getRemoteUser() +
> "</td></tr>");
> out.println("<tr><td>Remote address</td><td>" + req.getRemoteAddr() +
> "</td></tr>");
> out.println("<tr><td>Remote host</td><td>" + req.getRemoteHost() +
> "</td></tr>");
> out.println("</table><BR><BR>");
>
> Enumeration e = req.getHeaderNames();
> if (e.hasMoreElements()) {
> out.println("<h4>Request headers:</h4>");
> out.println("<TABLE Border=\"2\" WIDTH=\"65%\"
> BGCOLOR=\"#DDDDFF\">");
> while (e.hasMoreElements()) {
> String name = (String)e.nextElement();
> out.println("<tr><td>" + name + "</td><td>" + req.getHeader(name) +
> "</td></tr>");
> }
> out.println("</table><BR><BR>");
> }
>
> e = req.getParameterNames();
> if (e.hasMoreElements()) {
> out.println("<h4>Servlet parameters:</h4>");
> out.println("<TABLE Border=\"2\" WIDTH=\"65%\"
> BGCOLOR=\"#DDDDFF\">");
> while (e.hasMoreElements()) {
> String name = (String)e.nextElement();
> out.println("<tr><td>" + name + "</td><td>" +
> req.getParameter(name) + "</td></tr>");
> }
> out.println("</table><BR><BR>");
> }
>
> HttpSession session = req.getSession(false);
> if (session != null) {
> out.println("<h4>Session information:</h4>");
> out.println("<TABLE Border=\"2\" WIDTH=\"65%\"
> BGCOLOR=\"#DDDDFF\">");
> out.println("<tr><td>Session ID</td><td>" + session.getId());
> out.println("<tr><td>Last accessed time</td><td>" + new
> Date(session.getLastAccessedTime()).toString() + "</td></tr>");
> out.println("<tr><td>Creation time</td><td>" + new
> Date(session.getCreationTime()).toString() + "</td></tr>");
> String mechanism = "unknown";
> if (req.isRequestedSessionIdFromCookie()) {
> mechanism = "cookie";
> } else if (req.isRequestedSessionIdFromURL()) {
> mechanism = "url-encoding";
> }
> out.println("Session-tracking mechanism" + mechanism);
> out.println("</table><BR><BR>");
>
> String[] vals = session.getValueNames();
> if (vals != null) {
> out.println("<h4>Session values</h4>");
> out.println("<TABLE Border=\"2\" WIDTH=\"65%\"
> BGCOLOR=\"#DDDDFF\">");
> for (int i=0; i<vals.length; i++) {
> String name = vals[i];
> out.println("<tr><td>" + name + "</td><td>" +
> session.getValue(name) + "</td></tr>");
> }
> out.println("</table><BR><BR>");
> }
> }
> out.println("</body></html>");
> }
> ---- snap ----
>
+1 on having this kind of examples for helping to handle legacy webapps.
But the servlet should not be printing HTML, HEAD, and BODY tags, just the HTML
fragments. Also, it should possibly check the getContentType() call, and deliver
HTML or WML as requested by the Portlet. But this last thing is not that important,
as the current psml allows to specify mime types in the registry.
Also, we should point people using it that it is not the way to go for new
development, just a way to get this servlet you had written before displayed in a
portlet.
>
> Best regards,
>
> Thomas
>
> Thomas Schaeck
> IBM Pervasive Computing Division
> e-mail: [EMAIL PROTECTED]
> Address: IBM Deutschland Entwicklung GmbH,
> Schoenaicher Str. 220, 71032 Boeblingen, Germany
>
> --
> --------------------------------------------------------------
> Please read the FAQ! <http://java.apache.org/faq/>
> To subscribe: [EMAIL PROTECTED]
> To unsubscribe: [EMAIL PROTECTED]
> Archives and Other: <http://java.apache.org/main/mail.html>
> Problems?: [EMAIL PROTECTED]
--
--------------------------------------------------------------
Please read the FAQ! <http://java.apache.org/faq/>
To subscribe: [EMAIL PROTECTED]
To unsubscribe: [EMAIL PROTECTED]
Archives and Other: <http://java.apache.org/main/mail.html>
Problems?: [EMAIL PROTECTED]
