com.amazon.photosharing.servlets.PrivateMediaServlet.java Source code

Introduction

Here is the source code for com.amazon.photosharing.servlets.PrivateMediaServlet.java

Source

/*
 * Copyright 2010-2017 Amazon.com, Inc. or its affiliates. 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.
 * A copy of the License is located at
 *
 *  http://aws.amazon.com/apache2.0
 *
 * or in the "license" file accompanying this file. This file 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.amazon.photosharing.servlets;

import java.io.IOException;
import java.util.Date;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.amazon.photosharing.dao.Media;
import com.amazon.photosharing.facade.ContentFacade;
import com.amazon.photosharing.utils.ContentHelper;
import com.amazonaws.services.s3.model.S3ObjectInputStream;
import com.amazonaws.util.IOUtils;

@WebServlet(name = "media", urlPatterns = { "/private/media/*" }, asyncSupported = true, loadOnStartup = 3)
public class PrivateMediaServlet extends AbstractServlet {

    private static final long serialVersionUID = 3035142586019273646L;

    protected final Logger _logger = LoggerFactory.getLogger(this.getClass());

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        try {
            getPrivateContent(req, resp);
        } catch (Exception e) {
            _logger.error(e.getMessage(), e);
            resp.sendError(HttpServletResponse.SC_BAD_REQUEST);
        }
    }

    private void getPrivateContent(HttpServletRequest p_req, HttpServletResponse p_resp)
            throws ServletException, IOException {
        Media m = new ContentFacade().findMedia(Long.parseLong(p_req.getPathInfo().substring(1)));
        if (m == null)
            p_resp.sendError(HttpServletResponse.SC_BAD_REQUEST);

        addHeaders(p_resp, m);
        if (m.getUser().getId().equals(Long.parseLong(p_req.getRemoteUser()))) {
            if (p_req.getParameter("format") != null && p_req.getParameter("format").equals("thumb"))
                streamS3Content(m.getS3Bucket(), m.getS3ThumbFileName(), p_resp, false);
            else
                streamS3Content(m.getS3Bucket(), m.getS3FileName(), p_resp, false);
        }
    }

    private void addHeaders(HttpServletResponse p_resp, Media m) {
        long expires = new Date().getTime() + (1000 * 3600 * 24); //24h       
        p_resp.setDateHeader("Expires", expires);
    }

    private void streamS3Content(String p_s3_bucket, String p_s3_file, HttpServletResponse p_resp,
            boolean p_no_retry) throws IOException {
        S3ObjectInputStream stream = ContentHelper.getInstance().downloadContent(p_s3_bucket, p_s3_file);
        if (stream != null) {
            try {
                IOUtils.copy(stream, p_resp.getOutputStream());
            } catch (IOException e) {
                //usually broken pipe if user cancels
            } finally {
                stream.close();
                p_resp.getOutputStream().flush();
                p_resp.getOutputStream().close();
            }
        } else {
            try {
                Thread.sleep(1000); //back off. eventually consistency S3 responses..
            } catch (InterruptedException e) {
                //why would that happen?
            }
            if (!p_no_retry)
                streamS3Content(p_s3_bucket, p_s3_file, p_resp, true);
        }
    }

    @Override
    protected long getLastModified(HttpServletRequest req) {
        try {
            ContentFacade f = new ContentFacade();
            Media m = f.findMedia(Long.parseLong(req.getPathInfo().substring(1)));
            f.done();
            if (m != null)
                return m.getCreateTime().getTime();
        } catch (Exception e) {
            _logger.error(e.getMessage(), e);
        }
        return 0;
    }
}