Java tutorial
/* * #! * Ontopia Navigator * #- * Copyright (C) 2001 - 2013 The Ontopia Project * #- * 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 net.ontopia.topicmaps.nav2.portlets.pojos; import java.io.IOException; import java.net.URL; import java.util.ArrayList; import java.util.Collection; import java.util.Collections; import java.util.HashMap; import java.util.Iterator; import java.util.List; import java.util.Map; import net.ontopia.infoset.core.LocatorIF; import net.ontopia.infoset.impl.basic.URILocator; import net.ontopia.topicmaps.core.TopicIF; import net.ontopia.topicmaps.core.TopicMapIF; import net.ontopia.topicmaps.query.core.InvalidQueryException; import net.ontopia.topicmaps.query.core.QueryResultIF; import net.ontopia.topicmaps.query.utils.QueryWrapper; import net.ontopia.topicmaps.query.utils.RowMapperIF; import net.ontopia.topicmaps.utils.TopicStringifiers; import net.ontopia.topicmaps.xml.TMXMLReader; import net.ontopia.utils.StringifierIF; import org.apache.commons.lang3.StringUtils; import org.xml.sax.InputSource; /** * PUBLIC: A component for including links to relevant pages from * other web sites via TMRAP. */ public class TMRAP { private Collection servers; private StringifierIF strify; private static Map cache = new HashMap(); /** * PUBLIC: Creates the component and configures it with a set of * servers to query. * @param servers a collection of TMRAP endpoint URIs as strings */ public TMRAP(Collection servers) { this.servers = servers; this.strify = TopicStringifiers.getDefaultStringifier(); } /** * PUBLIC: Sends a query, returning a model of the result. */ public Collection query(TopicIF topic) throws IOException, InvalidQueryException { Collection psis = new ArrayList(); Iterator it = topic.getSubjectIdentifiers().iterator(); while (it.hasNext()) { LocatorIF psi = (LocatorIF) it.next(); psis.add(psi.getAddress()); } return query(psis); } /** * PUBLIC: Sends a query, returning a model of the result. * @param psis a collection of PSIs as strings * @return a list of Server objects */ public Collection query(Collection psis) throws IOException, InvalidQueryException { if (psis.isEmpty()) return Collections.EMPTY_SET; String psikey = makeKey(psis); Collection model = new ArrayList(); Iterator it = servers.iterator(); while (it.hasNext()) { String endpoint = (String) it.next(); // is it in the cache? if (cache.containsKey(endpoint + psikey)) { CacheEntry entry = (CacheEntry) cache.get(endpoint + psikey); model.add(entry.getObject()); continue; } // not in cache, so go look it up InputSource src = getInputSource(endpoint, psis); TMXMLReader reader = new TMXMLReader(src, new URILocator(src.getSystemId())); TopicMapIF topicmap = reader.read(); QueryWrapper qw = new QueryWrapper(topicmap); qw.setDeclarations("using tmrap for i\"http://psi.ontopia.net/tmrap/\" "); Server server = (Server) qw.queryForObject("instance-of($S, tmrap:server)?", new Factory()); model.add(server); qw.queryForList("instance-of($TM, tmrap:topicmap)?", new Factory(server)); // process the topic maps Iterator it2 = server.getTopicMaps().iterator(); while (it2.hasNext()) { TopicMap tm = (TopicMap) it2.next(); Map params = qw.makeParams("tm", tm.getTopic()); qw.queryForList("tmrap:contained-in(%tm% : tmrap:container, $P : tmrap:containee)?", new Factory(tm), params); } // update the cache cache.put(endpoint + psikey, new CacheEntry(server)); } return model; } public Collection getAllPages(Collection model) { Collection pages = new ArrayList(); Iterator it = model.iterator(); while (it.hasNext()) { Server server = (Server) it.next(); pages.addAll(server.getPages()); } return pages; } public Map getPageMap(Collection model) { Map map = new HashMap(); Iterator it = model.iterator(); while (it.hasNext()) { Server server = (Server) it.next(); Iterator it2 = server.getPages().iterator(); while (it2.hasNext()) { Page page = (Page) it2.next(); Collection pages; if (map.containsKey(page.getTypeURI())) pages = (Collection) map.get(page.getTypeURI()); else { pages = new ArrayList(); map.put(page.getTypeURI(), pages); } pages.add(page); } } return map; } /* ----- MODEL ----------------------------------------------------- */ public class Server { private TopicIF topic; private Collection topicmaps; public Server(TopicIF topic) { this.topic = topic; this.topicmaps = new ArrayList(); } public String getName() { return strify.toString(topic); } public TopicIF getTopic() { return topic; } public Collection getTopicMaps() { return topicmaps; } public Collection getPages() { Collection pages = new ArrayList(); Iterator it = topicmaps.iterator(); while (it.hasNext()) { TopicMap tm = (TopicMap) it.next(); pages.addAll(tm.getPages()); } return pages; } private void addTopicMap(TopicMap tm) { topicmaps.add(tm); } } public class TopicMap { private Server server; private TopicIF topic; private Collection pages; public TopicMap(Server server, TopicIF topic) { this.server = server; this.topic = topic; this.pages = new ArrayList(); server.addTopicMap(this); } public TopicIF getTopic() { return topic; } public Collection getPages() { return pages; } private void addPage(Page page) { pages.add(page); } } public class Page { // could be edit-page, view-page, or something else private TopicMap topicmap; private TopicIF topic; public Page(TopicMap topicmap, TopicIF topic) { this.topicmap = topicmap; this.topic = topic; topicmap.addPage(this); } public String getName() { return strify.toString(topic); } public String getURI() { LocatorIF loc = topic.getSubjectLocators().iterator().next(); return loc.getAddress(); } public String getTypeURI() { // tells us if it's edit-page, view-page ... if (topic.getTypes().isEmpty()) return null; TopicIF type = topic.getTypes().iterator().next(); if (type.getSubjectIdentifiers().isEmpty()) return null; LocatorIF psi = type.getSubjectIdentifiers().iterator().next(); return psi.getAddress(); } } class Factory implements RowMapperIF { private Server server; private TopicMap topicmap; private Factory() { } private Factory(Server server) { this.server = server; } private Factory(TopicMap topicmap) { this.topicmap = topicmap; } @Override public Object mapRow(QueryResultIF result, int rowno) { if (server == null && topicmap == null) return new Server((TopicIF) result.getValue(0)); if (server != null && topicmap == null) return new TopicMap(server, (TopicIF) result.getValue(0)); else return new Page(topicmap, (TopicIF) result.getValue(0)); } } /* ----- CACHE ENTRY ----------------------------------------------- */ class CacheEntry { private long time; private Server object; public CacheEntry(Server object) { this.object = object; this.time = System.currentTimeMillis(); } public Server getObject() { return object; } } /* ----- INTERNAL -------------------------------------------------- */ private InputSource getInputSource(String endpoint, Collection psis) throws IOException { String uri = addParameters(endpoint, psis); URL url = new URL(uri); InputSource src = new InputSource(uri); src.setByteStream(url.openStream()); return src; } private String addParameters(String endpoint, Collection psis) { StringBuilder buf = new StringBuilder(endpoint); buf.append('?'); Iterator it = psis.iterator(); while (it.hasNext()) { String psi = (String) it.next(); buf.append("identifier="); buf.append(StringUtils.replace(psi, "#", "%23")); if (it.hasNext()) buf.append("&"); } return buf.toString(); } private String makeKey(Collection psis) { List uris = new ArrayList(psis); Collections.sort(uris); StringBuilder sb = new StringBuilder(); for (int ix = 0; ix < uris.size(); ix++) sb.append((String) uris.get(ix)); return sb.toString(); } }