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 ----
Best regards,
Thomas
Thomas Schaeck
IBM Pervasive Computing Division
e-mail: [EMAIL PROTECTED]
Address: IBM Deutschland Entwicklung GmbH,
Schoenaicher Str. 220, 71032 Boeblingen, Germany
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