/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations under the License.
*/
package org.apache.shindig.gadgets.servlet;
import org.apache.shindig.common.servlet.HttpUtil;
import org.apache.shindig.common.servlet.InjectedServlet;
import org.apache.shindig.gadgets.GadgetContext;
import org.apache.shindig.gadgets.http.HttpRequest;
import org.apache.shindig.gadgets.render.Renderer;
import org.apache.shindig.gadgets.render.RenderingResults;
import com.google.inject.Inject;
import org.apache.commons.lang.StringEscapeUtils;
import java.io.IOException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* Servlet for rendering Gadgets.
*/
public class GadgetRenderingServlet extends InjectedServlet {
static final int DEFAULT_CACHE_TTL = 60 * 5;
private Renderer renderer;
@Inject
public void setRenderer(Renderer renderer) {
this.renderer = renderer;
}
private void render(HttpServletRequest req, HttpServletResponse resp) throws IOException {
if (req.getHeader(HttpRequest.DOS_PREVENTION_HEADER) != null) {
// Refuse to render for any request that came from us.
// TODO: Is this necessary for any other type of request? Rendering seems to be the only one
// that can potentially result in an infinite loop.
resp.sendError(HttpServletResponse.SC_FORBIDDEN);
return;
}
resp.setContentType("text/html");
resp.setCharacterEncoding("UTF-8");
GadgetContext context = new HttpGadgetContext(req);
RenderingResults results = renderer.render(context);
switch (results.getStatus()) {
case OK:
if (context.getIgnoreCache()) {
HttpUtil.setCachingHeaders(resp, 0);
} else if (req.getParameter("v") != null) {
// Versioned files get cached indefinitely
HttpUtil.setCachingHeaders(resp, true);
} else {
// Unversioned files get cached for 5 minutes by default, but this can be overridden
// with a query parameter.
int ttl = DEFAULT_CACHE_TTL;
String ttlStr = req.getParameter(ProxyBase.REFRESH_PARAM);
if (ttlStr != null) {
ttl = Integer.parseInt(ttlStr);
}
HttpUtil.setCachingHeaders(resp, ttl, true);
}
resp.getWriter().print(results.getContent());
break;
case ERROR:
resp.getWriter().print(StringEscapeUtils.escapeHtml(results.getErrorMessage()));
break;
case MUST_REDIRECT:
resp.sendRedirect(results.getRedirect().toString());
break;
}
}
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws IOException {
// If an If-Modified-Since header is ever provided, we always say
// not modified. This is because when there actually is a change,
// cache busting should occur.
if (req.getHeader("If-Modified-Since") != null &&
!"1".equals(req.getParameter("nocache")) &&
req.getParameter("v") != null) {
resp.setStatus(HttpServletResponse.SC_NOT_MODIFIED);
return;
}
render(req, resp);
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws IOException {
render(req, resp);
}
}