webworkvelocityservlet.java

webwork source

/*
 * WebWork, Web Application Framework
 *
 * Distributable under Apache license.
 * See terms of license at opensource.org
 */
package webwork.view.velocity;

import org.apache.velocity.Template;
import org.apache.velocity.app.Velocity;
import org.apache.velocity.context.Context;
import org.apache.velocity.servlet.VelocityServlet;
import org.apache.commons.logging.*;
import webwork.action.ServletActionContext;

import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.ServletException;
import java.io.IOException;

/**
 * Velocity integration servlet. Transfer action properties to Velocity
 * context and use WebWork configuration to supply Velocity with settings.
 *
 * This allows you to use Velocity templates as views of WebWork actions.
 *
 * @author Rickard 謆erg ([e-mail])
 * @version $Revision: 1.6 $
 */
public class WebWorkVelocityServlet extends VelocityServlet
{
   static final String CONTEXT = "velocity_context";
   static final String WEBWORK_UTIL = "webwork";

   protected Log log = LogFactory.getLog(getClass());

   public void init() throws ServletException
   {
     try
     {
       VelocityHelper.initVelocity(getServletContext());
     }
     catch(Exception e)
     {
       throw new ServletException(e);
     }
   }

   public void service(ServletRequest aRequest, ServletResponse aResponse) throws ServletException, IOException
   {
      long start = 0;
      if (log.isDebugEnabled())
         start = System.currentTimeMillis();

      super.service(aRequest, aResponse);

      if (log.isDebugEnabled())
      {
         log.debug("Time:"+(System.currentTimeMillis()-start));
      }
   }

   /**
    * Create a context that delegates to the standard context and
    * also allows Velocity to access properties from the ValueStack.
    */
   protected Context createContext(javax.servlet.http.HttpServletRequest request,
                                   javax.servlet.http.HttpServletResponse response)
   {
      return VelocityHelper.getContext(getServletContext(), request, response);
   }

   /**
    * Get the template to show.
    */
   protected Template handleRequest(javax.servlet.http.HttpServletRequest aRequest,
                                    javax.servlet.http.HttpServletResponse aResponse,
                                    Context ctx)
      throws java.lang.Exception
   {
      // Bind standard WebWork utility into context

      ServletActionContext.setContext(aRequest, aResponse, getServletContext(), null);
      ctx.put(WEBWORK_UTIL, new WebWorkUtil(ctx));

      String servletPath = (String)aRequest.getAttribute("javax.servlet.include.servlet_path");
      if (servletPath == null)
         servletPath = aRequest.getServletPath();
      return getTemplate(servletPath);
   }
}