Java tutorial
/** * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. 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. */ package org.apache.marmotta.ldclient.provider.phpbb; import org.apache.marmotta.commons.sesame.model.Namespaces; import com.google.common.collect.ImmutableList; import org.apache.http.NameValuePair; import org.apache.http.client.utils.URLEncodedUtils; import org.apache.marmotta.ldclient.api.endpoint.Endpoint; import org.apache.marmotta.ldclient.api.provider.DataProvider; import org.apache.marmotta.ldclient.provider.html.AbstractHTMLDataProvider; import org.apache.marmotta.ldclient.provider.html.mapping.CssTextLiteralMapper; import org.apache.marmotta.ldclient.provider.html.mapping.JSoupMapper; import org.apache.marmotta.ldclient.provider.phpbb.mapping.PHPBBForumHrefMapper; import org.apache.marmotta.ldclient.provider.phpbb.mapping.PHPBBTopicHrefMapper; import org.jsoup.nodes.Document; import org.jsoup.nodes.Element; import java.net.URI; import java.net.URISyntaxException; import java.util.Collections; import java.util.HashMap; import java.util.LinkedList; import java.util.List; import java.util.Map; /** * A wrapper that allows wrapping a whole PHPBB Forum, linking to all its topics. The resource will * be of type * sioc:Forum, have a dc:title, and have a sioc:container_of relation to all threads * <p/> * Author: Sebastian Schaffert */ public class PHPBBForumProvider extends AbstractHTMLDataProvider implements DataProvider { public static final String PROVIDER_NAME = "PHPBB Forum"; /** * Return a list of URIs that should be added as types for each processed resource. * * @return * @param resource */ @Override protected List<String> getTypes(org.openrdf.model.URI resource) { return ImmutableList.of(Namespaces.NS_SIOC + "Forum", Namespaces.NS_SIOC + "Collection", Namespaces.NS_FOAF + "Document"); } /** * Return a mapping table mapping from RDF properties to XPath Value Mappers. Each entry in the * map is evaluated * in turn; in case the XPath expression yields a result, the property is added for the * processed resource. * * @return * @param requestUrl */ @Override protected Map<String, JSoupMapper> getMappings(String resource, String requestUrl) { URI uri = null; try { uri = new URI(requestUrl); Map<String, String> params = new HashMap<String, String>(); for (NameValuePair p : URLEncodedUtils.parse(uri, "UTF-8")) { params.put(p.getName(), p.getValue()); } if (params.containsKey("f")) { Map<String, JSoupMapper> postMappings = new HashMap<String, JSoupMapper>(); if (params.containsKey("start")) { // when start is set, we only take the replies; we are in a second or further // page of the topic postMappings.put(Namespaces.NS_SIOC + "container_of", new PHPBBTopicHrefMapper("a.topictitle")); } else { // otherwise we also take the initial title, creator and date for the topic postMappings.put(Namespaces.NS_DC + "title", new CssTextLiteralMapper("div#pageheader a.titles")); postMappings.put(Namespaces.NS_DC + "description", new CssTextLiteralMapper("div#pageheader span.forumdesc")); postMappings.put(Namespaces.NS_SIOC + "container_of", new PHPBBTopicHrefMapper("a.topictitle")); postMappings.put(Namespaces.NS_SIOC + "parent_of", new PHPBBForumHrefMapper("a.forumlink, a.forumtitle")); } return postMappings; } else throw new RuntimeException( "the requested resource does not seem to identify a PHPBB Forum (t=... parameter missing)"); } catch (URISyntaxException e) { throw new RuntimeException( "the requested resource does not seem to identify a PHPBB Forum (URI syntax error)"); } } /** * Return the name of this data provider. To be used e.g. in the configuration and in log * messages. * * @return */ @Override public String getName() { return PROVIDER_NAME; } /** * Return the list of mime types accepted by this data provider. * * @return */ @Override public String[] listMimeTypes() { return new String[] { "text/html" }; } /** * Build the URL to use to call the webservice in order to retrieve the data for the resource * passed as argument. * In many cases, this will just return the URI of the resource (e.g. Linked Data), but there * might be data providers * that use different means for accessing the data for a resource, e.g. SPARQL or a Cache. * * * @param resource * @param endpoint endpoint configuration for the data provider (optional) * @return */ @Override public List<String> buildRequestUrl(String resource, Endpoint endpoint) { return Collections.singletonList(resource); } /** * Try to find further URLs in the document that need to be requested to complete the resource * data. * Used e.g. to parse the result of paging in HTML pages. The default implementation returns an * empty list. * <p/> * This implementation tries to locate the paging area of PHPBB and selects the last link of the * paging, which will be the "next" page. * * @param document * @param requestUrl * @return */ @Override protected List<String> findAdditionalRequestUrls(String resource, Document document, String requestUrl) { List<String> result = new LinkedList<String>(); // return the next page in the result list String foo = "a[href*='start='][href*='viewforum.php']"; List<Element> values = document.select(foo); for (Element e : values) { String baseUrl = e.absUrl("href"); if (baseUrl.length() > 0) { result.add(baseUrl); } } return result; } }