/**
* $RCSfile$
* $Revision: $
* $Date: $
*
* Copyright (C) 2005-2008 Jive Software. All rights reserved.
*
* Licensed 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.jivesoftware.util;
import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.MultiThreadedHttpConnectionManager;
import org.apache.commons.httpclient.methods.GetMethod;
import org.apache.commons.httpclient.params.HttpConnectionManagerParams;
import org.jivesoftware.util.cache.Cache;
import org.jivesoftware.util.cache.CacheFactory;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
/**
* Servlet that gets favicons of webservers and includes them in HTTP responses. This
* servlet can be used when getting a favicon can take some time so pages can use this
* servlet as the image source to let the page load quickly and get the favicon images
* as they are available.<p>
*
* This servlet expects the web application to have the <tt>images/server_16x16.gif</tt>
* file that is used when no favicon is found.
*
* @author Gaston Dombiak
*/
public class FaviconServlet extends HttpServlet {
/**
* The content-type of the images to return.
*/
private static final String CONTENT_TYPE = "image/x-icon";
/**
* Bytes of the default favicon to return when one was not found on a host.
*/
private byte[] defaultBytes;
/**
* Pool of HTTP connections to use to get the favicons
*/
private HttpClient client;
/**
* Cache the domains that a favicon was not found.
*/
private Cache<String, Integer> missesCache;
/**
* Cache the favicons that we've found.
*/
private Cache<String, byte[]> hitsCache;
@Override
public void init(ServletConfig config) throws ServletException {
super.init(config);
// Create a pool of HTTP connections to use to get the favicons
client = new HttpClient(new MultiThreadedHttpConnectionManager());
HttpConnectionManagerParams params = client.getHttpConnectionManager().getParams();
params.setConnectionTimeout(2000);
params.setSoTimeout(2000);
// Load the default favicon to use when no favicon was found of a remote host
try {
URL resource = config.getServletContext().getResource("/images/server_16x16.gif");
defaultBytes = getImage(resource.toString());
}
catch (MalformedURLException e) {
e.printStackTrace();
}
// Initialize caches.
missesCache = CacheFactory.createCache("Favicon Misses");
hitsCache = CacheFactory.createCache("Favicon Hits");
}
/**
* Retrieve the image based on it's name.
*
* @param request the httpservletrequest.
* @param response the httpservletresponse.
* @throws javax.servlet.ServletException
* @throws java.io.IOException
*/
@Override
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException
{
String host = request.getParameter("host");
// Check special cases where we need to change host to get a favicon
host = "gmail.com".equals(host) ? "google.com" : host;
byte[] bytes = getImage(host, defaultBytes);
if (bytes != null) {
writeBytesToStream(bytes, response);
}
}
/**
* Writes out a <code>byte</code> to the ServletOuputStream.
*
* @param bytes the bytes to write to the <code>ServletOutputStream</code>.
*/
private void writeBytesToStream(byte[] bytes, HttpServletResponse response) {
response.setContentType(CONTENT_TYPE);
// Send image
try {
ServletOutputStream sos = response.getOutputStream();
sos.write(bytes);
sos.flush();
sos.close();
}
catch (IOException e) {
// Do nothing
}
}
/**
* Returns the favicon image bytes of the specified host.
*
* @param host the name of the host to get its favicon.
* @return the image bytes found, otherwise null.
*/
private byte[] getImage(String host, byte[] defaultImage) {
// If we've already attempted to get the favicon twice and failed,
// return the default image.
if (missesCache.get(host) != null && missesCache.get(host) > 1) {
// Domain does not have a favicon so return default icon
return defaultImage;
}
// See if we've cached the favicon.
if (hitsCache.containsKey(host)) {
return hitsCache.get(host);
}
byte[] bytes = getImage("http://" + host + "/favicon.ico");
if (bytes == null) {
// Cache that the requested domain does not have a favicon. Check if this
// is the first cache miss or the second.
if (missesCache.get(host) != null) {
missesCache.put(host, 2);
}
else {
missesCache.put(host, 1);
}
// Return byte of default icon
bytes = defaultImage;
}
// Cache the favicon.
else {
hitsCache.put(host, bytes);
}
return bytes;
}
private byte[] getImage(String url) {
try {
// Try to get the fiveicon from the url using an HTTP connection from the pool
// that also allows to configure timeout values (e.g. connect and get data)
GetMethod get = new GetMethod(url);
get.setFollowRedirects(true);
int response = client.executeMethod(get);
if (response < 400) {
// Check that the response was successful. Should we also filter 30* code?
return get.getResponseBody();
}
else {
// Remote server returned an error so return null
return null;
}
}
catch (IllegalStateException e) {
// Something failed (probably a method not supported) so try the old stye now
try {
URLConnection urlConnection = new URL(url).openConnection();
urlConnection.setReadTimeout(1000);
urlConnection.connect();
DataInputStream di = new DataInputStream(urlConnection.getInputStream());
ByteArrayOutputStream byteStream = new ByteArrayOutputStream();
DataOutputStream out = new DataOutputStream(byteStream);
int len;
byte[] b = new byte[1024];
while ((len = di.read(b)) != -1) {
out.write(b, 0, len);
}
di.close();
out.flush();
return byteStream.toByteArray();
}
catch (IOException ioe) {
// We failed again so return null
return null;
}
}
catch (IOException ioe) {
// We failed so return null
return null;
}
}
}