/* ====================================================================
* The Apache Software License, Version 1.1
*
* Copyright (c) 2000-2003 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://apache.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Apache" and "Apache Software Foundation", "Tapestry"
* must not be used to endorse or promote products derived from this
* software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache"
* or "Tapestry", nor may "Apache" or "Tapestry" appear in their
* name, without prior written permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE TAPESTRY CONTRIBUTOR COMMUNITY
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
*/
package org.apache.tapestry.engine;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.tapestry.ApplicationRuntimeException;
import org.apache.tapestry.IComponent;
import org.apache.tapestry.IMarkupWriter;
import org.apache.tapestry.IRequestCycle;
import org.apache.tapestry.Tapestry;
import org.apache.tapestry.html.HTMLWriter;
import org.apache.tapestry.request.RequestContext;
import org.apache.tapestry.request.ResponseOutputStream;
/**
* A very specialized service used by JSPs to access Tapestry URLs.
* This is used by the Tapestry JSP tags, such as
* {@link org.apache.tapestry.jsp.PageTag}.
*
* @author Howard Lewis Ship
* @version $Id: TagSupportService.java,v 1.6 2003/05/28 13:41:39 hlship Exp $
* @since 3.0
* @see org.apache.tapestry.jsp.URLRetriever
*
**/
public class TagSupportService implements IEngineService
{
/**
* Not to be invoked; this service is different than the others.
*
* @throws ApplicationRuntimeException always
*
**/
public ILink getLink(IRequestCycle cycle, IComponent component, Object[] parameters)
{
throw new ApplicationRuntimeException(Tapestry.getMessage("TagSupportService.service-only"));
}
public void service(
IEngineServiceView engine,
IRequestCycle cycle,
ResponseOutputStream output)
throws ServletException, IOException
{
RequestContext context = cycle.getRequestContext();
HttpServletRequest request = context.getRequest();
String serviceName = getAttribute(request, Tapestry.TAG_SUPPORT_SERVICE_ATTRIBUTE);
Object raw = request.getAttribute(Tapestry.TAG_SUPPORT_PARAMETERS_ATTRIBUTE);
Object[] parameters = null;
try
{
parameters = (Object[]) raw;
}
catch (ClassCastException ex)
{
throw new ServletException(
Tapestry.format(
"TagSupportService.attribute-not-array",
Tapestry.TAG_SUPPORT_PARAMETERS_ATTRIBUTE,
Tapestry.getClassName(raw.getClass())));
}
IEngineService service = cycle.getEngine().getService(serviceName);
ILink link = service.getLink(cycle, null, parameters);
String URI = link.getURL();
HttpServletResponse response = context.getResponse();
PrintWriter servletWriter = response.getWriter();
IMarkupWriter writer = new HTMLWriter(servletWriter);
writer.print(URI);
writer.flush();
}
private String getAttribute(HttpServletRequest request, String name) throws ServletException
{
Object result = request.getAttribute(name);
if (result == null)
throw new ServletException(
Tapestry.format("TagSupportService.null-attribute", name));
try
{
return (String) result;
}
catch (ClassCastException ex)
{
throw new ServletException(
Tapestry.format(
"TagSupportService.attribute-not-string",
name,
Tapestry.getClassName(result.getClass())));
}
}
/**
* @return {@link org.apache.tapestry.Tapestry#TAGSUPPORT_SERVICE}.
*
**/
public String getName()
{
return Tapestry.TAGSUPPORT_SERVICE;
}
}