/**
* Licensed under the Artistic License; you may not use this file
* except in compliance with the License.
* You may obtain a copy of the License at
*
* http://displaytag.sourceforge.net/license.html
*
* THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
package org.displaytag.filter;
import java.util.HashMap;
import java.util.Map;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.displaytag.Messages;
import org.displaytag.tags.TableTag;
import org.displaytag.tags.TableTagParameters;
import org.springframework.web.servlet.HandlerAdapter;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter;
/**
* <p>
* Allow the author of an included JSP page to reset the content type to something else (like a binary stream), and then
* write the new info back as the exclusive response, clearing the buffers of all previously added content.
* </p>
* <p>
* This interceptor allows TableTag users to perform exports from pages that are run as includes, such as from Struts or
* a jsp:include. If that is your intention, just add this interceptor to your spring dispatcher context xml and map it
* to the appropriate requests, using something like:
* </p>
*
* <pre>
* <bean id="urlMapping" class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">
* <property name="interceptors">
* <list>
* <bean class="org.displaytag.filter.DisplayTagSpringInterceptor"/>
* </list>
* </property
* </bean>
* </pre>
*
* <p>
* By default the interceptor buffers all the export content before writing it out. You can set an optional parameter
* <code>buffer</code> to <code>false</code> to make the interceptor write directly to the output stream. This could
* be faster and uses less memory, but the content length will not be set.
* </p>
*
* <pre>
* <bean class="org.displaytag.filter.DisplayTagSpringInterceptor">
* <property name="buffer"><value>false</value></property>
* </bean>
* </pre>
*
* @author Keith Garry Boyce
* @author rapruitt
* @author Fabrizio Giustina
* @version $Revision: 1081 $ ($Author: fgiust $)
*/
public class DisplayTagSpringInterceptor implements HandlerInterceptor
{
/**
* Logger.
*/
static Log log = LogFactory.getLog(DisplayTagSpringInterceptor.class);
/**
* Force response buffering. Enabled by default.
*/
private boolean buffer = true;
/**
* Sets the buffer state.
* @param bufferingEnabled it <code>true</code> buffering will be used
*/
public void setBuffer(boolean bufferingEnabled)
{
this.buffer = bufferingEnabled;
}
/**
* @see HandlerInterceptor#preHandle(HttpServletRequest,HttpServletResponse, Object)
*/
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception
{
if (request.getParameter(TableTagParameters.PARAMETER_EXPORTING) == null)
{
if (log.isDebugEnabled())
{
log.debug(Messages.getString("ResponseOverrideFilter.parameternotfound")); //$NON-NLS-1$
}
// don't intercept!
return true;
}
BufferedResponseWrapper wrapper = new BufferedResponseWrapper13Impl(response);
Map contentBean = new HashMap(4);
if (buffer)
{
contentBean.put(TableTagParameters.BEAN_BUFFER, Boolean.TRUE);
}
request.setAttribute(TableTag.FILTER_CONTENT_OVERRIDE_BODY, contentBean);
if (log.isDebugEnabled())
{
log.debug("handler is " + handler);
}
HandlerAdapter handlerAdaptor = new SimpleControllerHandlerAdapter();
handlerAdaptor.handle(request, wrapper, handler);
ExportDelegate.writeExport(response, request, wrapper);
return false;
}
/**
* @see HandlerInterceptor#postHandle(HttpServletRequest,HttpServletResponse, Object, ModelAndView)
*/
public void postHandle(HttpServletRequest request, HttpServletResponse response, Object obj,
ModelAndView modelAndView) throws Exception
{
// Nothing to do
}
/**
* @see HandlerInterceptor#afterCompletion(HttpServletRequest,HttpServletResponse, Object, Exception)
*/
public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object obj,
Exception exception) throws Exception
{
// Nothing to do
}
}