| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. The ASF licenses this file to You |
| * 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. For additional information regarding |
| * copyright in this work, please see the NOTICE file in the top level |
| * directory of this distribution. |
| */ |
| |
| package org.apache.roller.planet.business.fetcher; |
| |
| import java.util.Date; |
| import org.apache.roller.planet.pojos.Subscription; |
| |
| |
| /** |
| * A FeedFetcher is what is responsible for actually pulling subscriptions from |
| * their source and transforming them into Roller Planet Subscriptions and Entries. |
| * |
| * It does not perform any persistence of feeds. |
| */ |
| public interface FeedFetcher { |
| |
| /** |
| * Fetch a single subscription. |
| * |
| * This method takes in a feed url and is expected to fetch that feed and |
| * return a transient instance of a Subscription representing the |
| * given feed. |
| * |
| * It is important to understand that this method will *NOT* return a |
| * persistent version of an existing Subscription if it happens to |
| * exist. This method is only here to pull feeds from their source |
| * so that they may be used in any way desired by the rest of the system. |
| * |
| * @param feedURL The feed url to use when fetching the subscription. |
| * @return Subscription The fetched subscription. |
| * @throws FetcherException If there is an error fetching the subscription. |
| */ |
| Subscription fetchSubscription(String feedURL) throws FetcherException; |
| |
| |
| /** |
| * Conditionally fetch a single subscription. |
| * |
| * This method takes in a feed url and its known last modified date and should |
| * return a transient Subscription for the feed only if the given feed has |
| * been updated since the lastModified date. This method is meant provide |
| * a more efficient way to fetch subscriptions which are being updated so |
| * subscriptions are not continually fetched when unnecessary. |
| * |
| * It is important to understand that this method will *NOT* return a |
| * persistent version of an existing Subscription if it happens to |
| * exist. This method is only here to pull feeds from their source |
| * so that they may be used in any way desired by the rest of the system. |
| * |
| * @param feedURL The feed url to use when fetching the subscription. |
| * @return Subscription The fetched subscription. |
| * @throws FetcherException If there is an error fetching the subscription. |
| */ |
| Subscription fetchSubscription(String feedURL, Date lastModified) throws FetcherException; |
| |
| } |