Initial version. JM-495

git-svn-id: http://svn.igniterealtime.org/svn/repos/wildfire/trunk@3645 b35dd754-fafc-0310-a699-88a17e54d16e

src/java/org/jivesoftware/util/FaviconServlet.java

+/**
+ * $RCSfile$
+ * $Revision: $
+ * $Date: $
+ *
+ * Copyright (C) 2006 Jive Software. All rights reserved.
+ *
+ * This software is published under the terms of the GNU Public License (GPL),
+ * a copy of which is included in this distribution.
+ */
+
+package org.jivesoftware.util;
+
+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.ByteArrayOutputStream;
+import java.io.DataInputStream;
+import java.io.DataOutputStream;
+import java.io.IOException;
+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/jpeg";
+    private byte[] defaultBytes;
+
+
+    public void init(ServletConfig config) throws ServletException {
+        super.init(config);
+        try {
+            URL resource = config.getServletContext().getResource("/images/server_16x16.gif");
+            defaultBytes = getImage(resource.toString());
+        }
+        catch (MalformedURLException e) {
+            e.printStackTrace();
+        }
+    }
+
+    /**
+     * Retrieve the image based on it's name.
+     *
+     * @param request  the httpservletrequest.
+     * @param response the httpservletresponse.
+     * @throws javax.servlet.ServletException
+     * @throws java.io.IOException
+     */
+    public void doGet(HttpServletRequest request, HttpServletResponse response)
+            throws ServletException, IOException {
+        String host = request.getParameter("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) {
+        byte[] bytes = getImage("http://" + host + "/favicon.ico");
+        if (bytes == null) {
+            // Return byte of default icon
+            bytes = defaultImage;
+        }
+        return bytes;
+    }
+
+    private byte[] getImage(String url) {
+        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 e) {
+            return null;
+        }
+    }
+
+}