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.util.ArrayList; import java.util.Collection; import java.util.Collections; import java.util.HashMap; import java.util.HashSet; import java.util.Iterator; import java.util.List; import java.util.Map; import net.ontopia.topicmaps.core.AssociationIF; import net.ontopia.topicmaps.core.OccurrenceIF; import net.ontopia.topicmaps.core.TopicIF; import net.ontopia.topicmaps.core.TopicMapBuilderIF; import net.ontopia.topicmaps.core.TopicMapIF; import net.ontopia.topicmaps.core.TopicNameIF; import net.ontopia.topicmaps.nav2.portlets.pojos.Menu.Heading; import net.ontopia.topicmaps.nav2.portlets.pojos.Menu.Item; import net.ontopia.topicmaps.query.core.DeclarationContextIF; import net.ontopia.topicmaps.query.core.InvalidQueryException; import net.ontopia.topicmaps.query.core.ParsedQueryIF; import net.ontopia.topicmaps.query.core.QueryProcessorIF; import net.ontopia.topicmaps.query.core.QueryResultIF; import net.ontopia.topicmaps.query.utils.QueryUtils; import net.ontopia.utils.OntopiaRuntimeException; import org.apache.commons.lang3.StringUtils; /** * INTERNAL: Helper methods for Menu. */ public class MenuUtils { // Indicates that a menu item (ItemIF) should be moved up the list. public static final boolean UP = true; // Indicates that a menu item (ItemIF) should be moved down the list. public static final boolean DOWN = false; /** * Runs the given query with the given topic as parameter %topic% and returns * the first value (of the first collumn) in the result collection. * @param topic The parameter refered to as %topic% in the query. * @param pq The query that genereates the result. * @return The first value returned by the query. */ public static Object getFirstValue(TopicIF topic, ParsedQueryIF pq) { QueryResultIF qr = null; try { qr = pq.execute(Collections.singletonMap("topic", topic)); while (qr.next()) { return qr.getValue(0); } } catch (InvalidQueryException e) { throw new OntopiaRuntimeException(e); } finally { if (qr != null) qr.close(); } return null; } /** * Get the values of a given query with a given %topic% parameter as a List * @param topic The topic parameter represened by %topic% in the query. * @param parsedQuery The query. * @return the first result column values of the query, as a List. */ public static List getResultValues(TopicIF topic, ParsedQueryIF parsedQuery) { List topics = new ArrayList(); QueryResultIF qr = null; try { qr = parsedQuery.execute(Collections.singletonMap("topic", topic)); while (qr.next()) { topics.add(qr.getValue(0)); } } catch (InvalidQueryException e) { throw new OntopiaRuntimeException(e); } finally { if (qr != null) qr.close(); } return topics; } /** * Test if the given query returns any result rows. * @param topic The %topic% parameter in the query. * @param query The query. * @return true if query returns one or more result rows. Otherwise, false. */ public static boolean getResultTrue(TopicIF topic, String query) { Map params = new HashMap(); params.put("topic", topic); QueryProcessorIF proc = QueryUtils.getQueryProcessor(topic.getTopicMap()); QueryResultIF qr = null; try { qr = proc.execute(query, params); return qr.next(); } catch (InvalidQueryException e) { throw new OntopiaRuntimeException(e); } finally { if (qr != null) qr.close(); } } /** * Create new Heading as child of the given parent * @param topic Represents the parent. * @param title The title of the Heading. * @return The Heading that was created. */ public static Heading createHeading(TopicIF topic, String title) { return (Heading) createChild(topic, title, true); } /** * Create new Item as child of the given parent * @param topic Represents the parent. * @param title The title of the Item. * @return The Item that was created. */ public static Item createItem(TopicIF topic, String title) { return (Item) createChild(topic, title, false); } /** * Move the given child one step up or down the list of children on the parent * @param topic Represents the chils. * @param up use UP or DOWN to move up or down the list, respectively. */ public static void moveOne(TopicIF topic, boolean up) { TopicMapIF tm = topic.getTopicMap(); QueryProcessorIF qp = QueryUtils.getQueryProcessor(tm); DeclarationContextIF dc = optimisticParse(tm, "using menu for i\"http://psi.ontopia.net/portal/menu/\""); ParsedQueryIF neighbourQuery = optimisticParse(qp, dc, "select $CSORT, $CVAL from " + "menu:parent-child($PARENT : menu:parent, %topic% : menu:child), " + "menu:parent-child($PARENT : menu:parent, $CHILD : menu:child), " + "occurrence(%topic%, $HSORT), type($HSORT, menu:sort), " + "occurrence($CHILD, $CSORT), type($CSORT, menu:sort), " + "value($HSORT, $HVAL), value($CSORT, $CVAL)," + "$HVAL " + (up ? ">" : "<") + " $CVAL order by $CVAL?"); ParsedQueryIF sortKeyQuery = optimisticParse(qp, dc, "occurrence(%topic%, $SORT), type($SORT, menu:sort)?"); // Get the sort key of this heading OccurrenceIF sortKey = (OccurrenceIF) getFirstValue(topic, sortKeyQuery); // Get the neighbour (previous/next) sort key. OccurrenceIF neighbourKey = up ? getLastOfQuery(topic, neighbourQuery) : getFirstOfQuery(topic, neighbourQuery); // Can't move beyond the extremes of the list. if (neighbourKey == null) return; // Swap sort keys String swap = sortKey.getValue(); sortKey.setValue(neighbourKey.getValue()); neighbourKey.setValue(swap); } /** * Set the basename of a given topic, removing any old basenames. * @param topic The topic. * @param baseName The new basename. */ public static void setUniqueTopicName(TopicIF topic, String baseName) { TopicMapBuilderIF builder = topic.getTopicMap().getBuilder(); Collection oldTopicNames = new HashSet(topic.getTopicNames()); Iterator oldTopicNamesIt = oldTopicNames.iterator(); while (oldTopicNamesIt.hasNext()) { TopicNameIF currentTopicName = (TopicNameIF) oldTopicNamesIt.next(); currentTopicName.remove(); } builder.makeTopicName(topic, baseName); } /** * Set the occurrence of a given type on a given topic, removing any existing * occurrences of the same type on that topic. * @param topic The topic that should have the occurrence. * @param typeId The type, as refered to in the query (e.g. "menu:link") * @param value The value of the occurrence. */ public static void setUniqueOccurrence(TopicIF topic, String typeId, String value) { String query = "select $LINK from " + "occurrence(%topic%, $LINK), type($LINK, " + typeId + ")?"; List occs = getResultValues(topic, query); Iterator occsIt = occs.iterator(); while (occsIt.hasNext()) { OccurrenceIF occ = (OccurrenceIF) occsIt.next(); occ.remove(); } TopicMapIF tm = topic.getTopicMap(); TopicIF type = getTopic(typeId, tm); TopicMapBuilderIF builder = tm.getBuilder(); builder.makeOccurrence(topic, type, value); } /** * Set the binary association with given role types, association types and * players, removing any existing associations with the same role types and * association type on player1. * @param player1 The first player, for which old associations are removed. * @param rType1Id The first role type, as a string (e.g. "menu:item") * @param aTypeId The association type, as a string (e.g. "menu:item-topic") * @param rType2Id The second role type, as a string (e.g. "menu:topic") * @param player2 The second player. */ public static void setUniqueAssociation(TopicIF player1, String rType1Id, String aTypeId, String rType2Id, TopicIF player2) { String query = "select $ASSOC from type($ASSOC, " + aTypeId + "), " + "association-role($ASSOC, $ROLE1), " + "type($ROLE1, " + rType1Id + "), " + "role-player($ROLE1, %topic%)?"; List assocs = getResultValues(player1, query); TopicMapIF tm = player1.getTopicMap(); Iterator assocsIt = assocs.iterator(); while (assocsIt.hasNext()) { AssociationIF assoc = (AssociationIF) assocsIt.next(); assoc.remove(); } TopicMapBuilderIF builder = tm.getBuilder(); TopicIF aType = getTopic(aTypeId, tm); TopicIF rType1 = getTopic(rType1Id, tm); TopicIF rType2 = getTopic(rType2Id, tm); AssociationIF assoc = builder.makeAssociation(aType); builder.makeAssociationRole(assoc, rType1, player1); builder.makeAssociationRole(assoc, rType2, player2); } /** * Parse the given query for the given topic map. * InvalidQueryExceptions thrown during the parse process are caught and * re-thrown with an additional message as OntopiaRuntimeExceptions. This * avoids external try {} catch() {} blocks around this method. * @param query The query to parse. * @param tm The topicmap used by the query. * @return A ParsedQueryIF representing the parsed query. */ protected static ParsedQueryIF optimisticParse(String query, TopicMapIF tm) { QueryProcessorIF qp = QueryUtils.getQueryProcessor(tm); DeclarationContextIF dc = optimisticParse(tm, "using menu for i\"http://psi.ontopia.net/portal/menu/\""); return optimisticParse(qp, dc, query); } /** * Parse the given declaration-context-query for the given topic map. * InvalidQueryExceptions thrown during the parse process are caught and * re-thrown with an additional message as OntopiaRuntimeExceptions. This * avoids external try {} catch() {} blocks around this method. * @param tm The topicmap used by the query. * @param query The query to parse. * @return A DeclarationContextIF representing the parsed query. */ protected static DeclarationContextIF optimisticParse(TopicMapIF tm, String query) { try { return QueryUtils.parseDeclarations(tm, query); } catch (InvalidQueryException e) { throw new OntopiaRuntimeException("There was a problem parsing the " + "query \"" + query + "\" probably due to an error in the menu ontology.", e); } } /** * Parse the given declaration-context-query for the given topic map. * InvalidQueryExceptions thrown during the parse process are caught and * re-thrown with an additional message as OntopiaRuntimeExceptions. This * avoids external try {} catch() {} blocks around this method. * @param qp The query processor that will process the query. * @param dc A declaration context to be used by the query. * @param query The query to parse. * @return A ParsedQueryIF representing the parsed query. */ private static ParsedQueryIF optimisticParse(QueryProcessorIF qp, DeclarationContextIF dc, String query) { try { return qp.parse(query, dc); } catch (InvalidQueryException e) { throw new OntopiaRuntimeException("There was a problem parsing the " + "query \"" + query + "\" probably due to an error in the menu ontology.", e); } } /** * Runs the given query with the given topic as parameter %topic% and returns * the last value (of the first collumn) in the result collection. * @param topic The parameter refered to as %topic% in the query. * @param query The query that genereates the result. * @return The last value returned by the query. */ private static String getLastValue(TopicIF topic, ParsedQueryIF query) { List resultValues = getResultValues(topic, query); if (resultValues.isEmpty()) return null; return (String) resultValues.get(resultValues.size() - 1); } /** * Get the result values of the given query with the given %topic% parameter. * @param topic Parameter represented by %topic% in the query. * @param query The query. * @return The first column of the result values. */ private static List getResultValues(TopicIF topic, String query) { TopicMapIF tm = topic.getTopicMap(); ParsedQueryIF pq = optimisticParse(query, tm); return getResultValues(topic, pq); } /** * Get the topic represented in queries by 'id' from the given topic map. * @param id The id of the topic as given in a query (e.g. "menu:item") * @param tm The topic map containing the sought topic. * @return The topic represented by 'id' */ private static TopicIF getTopic(String id, TopicMapIF tm) { QueryProcessorIF qp = QueryUtils.getQueryProcessor(tm); QueryResultIF qr = null; try { DeclarationContextIF dc = QueryUtils.parseDeclarations(tm, "using menu for i\"http://psi.ontopia.net/portal/menu/\""); qr = qp.execute("topic($T), $T = " + id + "?", dc); if (!qr.next()) throw new OntopiaRuntimeException("Getting topic '" + id + "' gave no results."); Object retObject = qr.getValue(0); if (!(retObject instanceof TopicIF)) throw new OntopiaRuntimeException( "Getting topic '" + id + "' should " + "give a result of type TopicIF, but" + " gave a result of type " + retObject.getClass().getName()); TopicIF retTopic = (TopicIF) retObject; if (qr.next()) throw new OntopiaRuntimeException("Getting topic '" + id + "' should give a unique result, but" + " gives more than one result."); return retTopic; } catch (InvalidQueryException e) { throw new OntopiaRuntimeException(e); } finally { if (qr != null) qr.close(); } } /** * Get the last value of the first column from the result of a given query. * @param topic Parameter represented by %topic% in the query. * @param query The query. * @return The last value of the first column from the result of the query. */ private static OccurrenceIF getLastOfQuery(TopicIF topic, ParsedQueryIF query) { List resultValues = (List) getResultValues(topic, query); if (resultValues.isEmpty()) return null; else return (OccurrenceIF) resultValues.get(resultValues.size() - 1); } /** * Get the first value of the first column from the result of a given query. * @param topic Parameter represented by %topic% in the query. * @param query The query. * @return The first value of the first column from the result of the query. */ private static OccurrenceIF getFirstOfQuery(TopicIF topic, ParsedQueryIF query) { List resultValues = (List) getResultValues(topic, query); if (resultValues.isEmpty()) return null; else return (OccurrenceIF) resultValues.get(0); } /** * Create a child (Heading or Item) of the parent represented by a given topic * @param topic The topic of the parent. * @param title The title of the new child. * @param isHeading true to create a Heading, false to create an Item. * @return */ private static Menu.ChildIF createChild(TopicIF topic, String title, boolean isHeading) { TopicMapIF tm = topic.getTopicMap(); TopicMapBuilderIF builder = tm.getBuilder(); QueryProcessorIF qp = QueryUtils.getQueryProcessor(tm); DeclarationContextIF dc = optimisticParse(tm, "using menu for i\"http://psi.ontopia.net/portal/menu/\""); TopicIF itemIFTopicType = getTopic(isHeading ? "menu:heading" : "menu:item", tm); TopicIF parentChildAssociation = getTopic("menu:parent-child", tm); TopicIF parentRoleType = getTopic("menu:parent", tm); TopicIF childRoleType = getTopic("menu:child", tm); TopicIF sortOccurrenceType = getTopic("menu:sort", tm); ParsedQueryIF sortKeysQuery = optimisticParse(qp, dc, "select $SORT from " + "menu:parent-child(%topic% : menu:parent, $CHILD : menu:child), " + "{ menu:sort($CHILD, $SORT) } order by $SORT?"); // Create the heading topic. TopicIF itemIFTopic = builder.makeTopic(itemIFTopicType); // Make the heading child of the menu. AssociationIF assoc = builder.makeAssociation(parentChildAssociation); builder.makeAssociationRole(assoc, parentRoleType, topic); builder.makeAssociationRole(assoc, childRoleType, itemIFTopic); // Get the highest sort key of children of this menu. String lastSortKey = getLastValue(topic, sortKeysQuery); int lastSortKeyInt = Integer.parseInt(lastSortKey); lastSortKeyInt++; String newSortKey = StringUtils.leftPad(Integer.toString(lastSortKeyInt), 3, '0'); builder.makeOccurrence(itemIFTopic, sortOccurrenceType, newSortKey); Menu.ChildIF itemIF; if (isHeading) itemIF = new Heading(itemIFTopic); else itemIF = new Item(itemIFTopic); itemIF.setTitle(title); return itemIF; } /** * Build the Heading of a given topic, from the topic map content. */ private static Heading buildHeading(TopicIF topic) { Heading heading = new Heading(topic); heading.children = buildChildren(topic); return heading; } /** * Build the Item of a given topic, from the topic map content. */ private static Item buildItem(TopicIF topic) { TopicMapIF tm = topic.getTopicMap(); ParsedQueryIF itemTopicQuery = MenuUtils.optimisticParse( "select $TOPIC from " + "menu:item-topic(%topic% : menu:item, $TOPIC : menu:topic)?", tm); ParsedQueryIF linkQuery = MenuUtils.optimisticParse("select $LINK from menu:link(%topic%, $LINK)?", tm); ParsedQueryIF imageQuery = MenuUtils.optimisticParse("select $IMAGE from menu:image(%topic%, $IMAGE)?", tm); Item item = new Item(topic); item.associatedTopic = (TopicIF) MenuUtils.getFirstValue(topic, itemTopicQuery); item.link = (String) MenuUtils.getFirstValue(topic, linkQuery); item.image = (String) MenuUtils.getFirstValue(topic, imageQuery); String query = item.getCondition(); item.condition = (query == null) || MenuUtils.getResultTrue(item.associatedTopic, query); return item; } /** * Build the List of children of a given parent, from the topic map content. */ private static List buildChildren(TopicIF topic) { TopicMapIF tm = topic.getTopicMap(); ParsedQueryIF childrenQuery = MenuUtils.optimisticParse( "select $CHILD, $SORT from " + "menu:parent-child(%topic% : menu:parent, $CHILD : menu:child), " + "{ menu:sort($CHILD, $SORT) } order by $SORT?", tm); ParsedQueryIF headingsQuery = MenuUtils.optimisticParse( "select $CHILD from " + "menu:parent-child(%topic% : menu:parent, $CHILD : menu:child), " + "instance-of($CHILD, menu:heading)?", tm); List childrenTopics = MenuUtils.getResultValues(topic, childrenQuery); List headingsTopics = MenuUtils.getResultValues(topic, headingsQuery); // populate children List children = new ArrayList(childrenTopics.size()); for (int i = 0; i < childrenTopics.size(); i++) { TopicIF child = (TopicIF) childrenTopics.get(i); if (headingsTopics.contains(child)) children.add(buildHeading(child)); else children.add(buildItem(child)); } return children; } }