/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. 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. For additional information regarding
* copyright in this work, please see the NOTICE file in the top level
* directory of this distribution.
*/
package org.apache.abdera.ext.json;
import java.io.IOException;
import java.io.OutputStream;
import java.net.URLDecoder;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.abdera.Abdera;
import org.apache.abdera.model.Document;
import org.apache.abdera.protocol.client.AbderaClient;
import org.apache.abdera.protocol.client.ClientResponse;
import org.apache.abdera.protocol.client.RequestOptions;
/**
* Servlet that will do an HTTP GET to retrieve an Atom document then convert that into a JSON doc. The URL pattern is
* simple: http://.../servlet/path/{url}
*/
@SuppressWarnings("unchecked")
public class JSONServlet extends HttpServlet {
private static final long serialVersionUID = 1414392196430276024L;
private Abdera getAbdera() {
ServletContext sc = getServletContext();
Abdera abdera = null;
synchronized (sc) {
abdera = (Abdera)sc.getAttribute(Abdera.class.getName());
if (abdera == null) {
abdera = new Abdera();
sc.setAttribute(Abdera.class.getName(), abdera);
}
}
return abdera;
}
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String url = request.getPathInfo();
if (url != null && url.length() > 1)
url = URLDecoder.decode(url, "UTF-8");
else {
response.sendError(400);
return;
}
url = url.substring(1);
Abdera abdera = getAbdera();
AbderaClient client = new AbderaClient(abdera);
RequestOptions options = client.getDefaultRequestOptions();
if (request.getHeader("If-Match") != null)
options.setIfMatch(request.getHeader("If-Match"));
if (request.getHeader("If-None-Match") != null)
options.setIfNoneMatch(request.getHeader("If-None-Match"));
if (request.getHeader("If-Modified-Since") != null)
options.setIfNoneMatch(request.getHeader("If-Modified-Since"));
if (request.getHeader("If-Unmodified-Since") != null)
options.setIfNoneMatch(request.getHeader("If-Unmodified-Since"));
ClientResponse resp = client.get(url);
switch (resp.getType()) {
case SUCCESS:
try {
Document doc = resp.getDocument();
response.setContentType("application/json");
response.setCharacterEncoding("UTF-8");
if (doc.getEntityTag() != null)
response.setHeader("ETag", doc.getEntityTag().toString());
if (doc.getLanguage() != null)
response.setHeader("Content-Language", doc.getLanguage());
if (doc.getLastModified() != null)
response.setDateHeader("Last-Modified", doc.getLastModified().getTime());
OutputStream out = response.getOutputStream();
doc.writeTo("json", out);
} catch (Exception e) {
response.sendError(500);
return;
}
case CLIENT_ERROR:
case SERVER_ERROR:
response.sendError(resp.getStatus(), resp.getStatusText());
return;
}
}
}