com.google.walkaround.wave.server.rpc.PhotosHandler.java Source code

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Here is the source code for com.google.walkaround.wave.server.rpc.PhotosHandler.java

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/*
 * Copyright 2011 Google Inc. 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 com.google.walkaround.wave.server.rpc;

import com.google.appengine.api.urlfetch.FetchOptions;
import com.google.appengine.api.urlfetch.HTTPMethod;
import com.google.appengine.api.urlfetch.HTTPRequest;
import com.google.appengine.api.urlfetch.HTTPResponse;
import com.google.common.net.UriEscapers;
import com.google.inject.Inject;
import com.google.walkaround.util.server.servlet.AbstractHandler;
import com.google.walkaround.wave.server.auth.OAuthedFetchService;
import com.google.walkaround.wave.server.util.ProxyHandler;
import com.google.walkaround.wave.shared.SharedConstants;

import java.io.IOException;
import java.net.URL;
import java.util.logging.Logger;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Handles photo requests by proxying them to the m8 feed.
 *
 * @author hearnden@google.com (David Hearnden)
 */
public final class PhotosHandler extends AbstractHandler {

    @SuppressWarnings("unused")
    private static final Logger log = Logger.getLogger(PhotosHandler.class.getName());

    private final OAuthedFetchService fetch;

    @Inject
    public PhotosHandler(OAuthedFetchService fetch) {
        this.fetch = fetch;
    }

    @Override
    public void doGet(HttpServletRequest req, HttpServletResponse resp) throws IOException {
        String photoId = requireParameter(req, "photoId");
        // http://code.google.com/apis/contacts/docs/2.0/developers_guide_protocol.html#groups_feed_url
        // says "You can also substitute 'default' for the user's email address,
        // which tells the server to return the contact groups for the user whose
        // credentials accompany the request".  I didn't read the document in enough
        // detail to check whether this is supposed to apply to photos as well, but
        // it seems to work.
        URL targetUrl = new URL("https://www.google.com/m8/feeds/photos/media/default/"
                + UriEscapers.uriQueryStringEscaper(false).escape(photoId));
        HTTPResponse response = fetch.fetch(
                new HTTPRequest(targetUrl, HTTPMethod.GET, FetchOptions.Builder.withDefaults().disallowTruncate()));
        if (response.getResponseCode() == 404) {
            // Rather than a broken image, use the unknown avatar.
            log.info("Missing image, using default");
            resp.sendRedirect(SharedConstants.UNKNOWN_AVATAR_URL);
        } else {
            ProxyHandler.copyResponse(response, resp);
        }
        // TODO(hearnden): Do something to make the client cache photos sensibly.
    }
}