mediaservice.java

google的gdata api包

        ((MediaEntry) entry).getMediaSource() : null;
    if (media == null) {
      return super.insert(feedUrl, entry);
    }

    InputStream resultStream = null;
    try {
      GDataRequest request;

      // Write as MIME multipart containing the entry and media
      MediaMultipart mediaMultipart = new MediaMultipart(entry, media);
      request =
          createRequest(GDataRequest.RequestType.INSERT, feedUrl,
              new ContentType(mediaMultipart.getContentType()));
      initMediaRequest(media, request);
      OutputStream outputStream = request.getRequestStream();
      mediaMultipart.writeTo(outputStream);

      request.execute();

      resultStream = request.getResponseStream();
      return (E) parseEntry(entry.getClass(), resultStream);

    } catch (MessagingException e) {
        throw new ServiceException("Unable to write MIME multipart message", e);
    } finally {
      if (resultStream != null) {
        resultStream.close();
      }
    }
  }

  /**
   * Inserts a new media resource read from {@link MediaSource} into a
   * media feed associated with the target service.  It will return the
   * resulting entry that describes the inserted media, including
   * any additional attributes or extensions set by the GData server.
   * To insert both the entry and the media content in a single request, use
   * {@link #insert(URL, BaseEntry)}.
   * <p>
   * If the media source has a name ({@link MediaSource#getName()} that is
   * non-null), the name will be provided as a Slug header that is sent
   * along with request and <i>may</i> be used as a hint when determining
   * the ID, url, and/or title of the inserted resource.
   *
   * @param feedUrl the POST URI associated with the target feed.
   * @param entryClass the class used to parse the returned entry.
   * @param media the media source that contains the media content to insert.
   * @return the newly inserted entry returned by the service.
   * @throws IOException error communicating with the GData service.
   * @throws com.google.gdata.util.ParseException error parsing the returned 
   *         entry data.
   * @throws ServiceException insert request failed due to system error.
   *
   * @see com.google.gdata.data.BaseFeed#getEntryPostLink()
   * @see com.google.gdata.data.media.MediaFeed#insert(MediaSource)
   */
  @SuppressWarnings({"unchecked"})
  public <E extends BaseEntry> E insert(URL feedUrl, Class<E> entryClass,
                                        MediaSource media)
      throws IOException, ServiceException {

    if (media == null) {
      throw new NullPointerException("Must supply media source");
    }

    InputStream resultStream = null;
    GDataRequest request;
    try {
      // Write media content only.
      request =
          createRequest(GDataRequest.RequestType.INSERT, feedUrl,
              new ContentType(media.getContentType()));
      initMediaRequest(media, request);

      // Write the media data
      MediaSource.Output.writeTo(media, request.getRequestStream());
      request.execute();
      resultStream = request.getResponseStream();
      return parseEntry(entryClass, resultStream);

    } finally {
      if (resultStream != null) {
        resultStream.close();
      }
    }
  }

  /**
   * Updates an existing entry and associated media resource by writing it
   * to the specified media edit URL.  The resulting entry (after update) will
   * be returned.  To update only the media content, use
   * {@link #updateMedia(URL, Class, MediaSource)}.
   *
   * @param mediaUrl the media edit URL associated with the resource.
   * @param entry the updated entry to be written to the server.
   * @return the updated entry returned by the service.
   * @throws IOException error communicating with the GData service.
   * @throws com.google.gdata.util.ParseException error parsing the updated 
   *         entry data.
   * @throws ServiceException update request failed due to system error.
   *
   * @see BaseEntry#getMediaEditLink()
   * @see MediaEntry#updateMedia(boolean)
   */
  @SuppressWarnings({"unchecked"})
  public <E extends BaseEntry> E updateMedia(URL mediaUrl, E entry)
      throws IOException, ServiceException {

    if (entry == null) {
      throw new NullPointerException("Must supply entry");
    }

    // Since the input parameter is a media-edit URL, this method should
    // not be used to post Atom-only entries.  These entries should be
    // sent to the edit URL.
    MediaSource media = (entry instanceof MediaEntry) ?
        ((MediaEntry) entry).getMediaSource() : null;
    if (media == null) {
      throw new NullPointerException("Must supply media source");
    }

    InputStream resultStream = null;
    GDataRequest request;
    try {
      // Write as MIME multipart containing the entry and media
      MediaMultipart mediaMultipart = new MediaMultipart(entry, media);
      request =
          createRequest(GDataRequest.RequestType.UPDATE, mediaUrl,
              new ContentType(mediaMultipart.getContentType()));
      OutputStream outputStream = request.getRequestStream();
      mediaMultipart.writeTo(outputStream);
      request.execute();

      resultStream = request.getResponseStream();
      return (E) parseEntry(entry.getClass(), resultStream);

    } catch (MessagingException e) {
      throw new ServiceException("Unable to write MIME multipart message", e);
    } finally {
      if (resultStream != null) {
        resultStream.close();
      }
    }
  }


  /**
   * Updates an existing media resource with data read from the
   * {@link MediaSource} by writing it it to the specified media edit URL.
   * The resulting entry (after update) will be returned.  To update both
   * the entry and the media content in a single request, use
   * {@link #updateMedia(URL, BaseEntry)}.
   *
   * @param mediaUrl the media edit URL associated with the resource.
   * @param entryClass the class that will be used to represent the
   *        resulting entry.
   * @param media the media source data to be written to the server.
   * @return the updated Entry returned by the service.
   * @throws IOException error communicating with the GData service.
   * @throws com.google.gdata.util.ParseException error parsing the updated 
   *         entry data.
   * @throws ServiceException update request failed due to system error.
   *
   * @see BaseEntry#getMediaEditLink()
   * @see MediaEntry#updateMedia(boolean)
   */
  @SuppressWarnings({"unchecked"})
  public <E extends BaseEntry> E updateMedia(URL mediaUrl,
                                        Class<E> entryClass,
                                        MediaSource media)
      throws IOException, ServiceException {

    // Since the input parameter is a media-edit URL, this method should
    // not be used to post Atom-only entries.  These entries should be
    // sent to the edit URL.
    if (media == null) {
      throw new NullPointerException("Must supply media source");
    }

    InputStream resultStream = null;
    GDataRequest request;
    try {
      request =
          createRequest(GDataRequest.RequestType.UPDATE, mediaUrl,
              new ContentType(media.getContentType()));
      MediaSource.Output.writeTo(media, request.getRequestStream());
      request.execute();

      resultStream = request.getResponseStream();
      return parseEntry(entryClass, resultStream);

    } finally {
      if (resultStream != null) {
        resultStream.close();
      }
    }
  }
}