Mercurial > dive4elements > river
view flys-artifacts/src/main/java/de/intevation/flys/artifacts/services/CrossSectionKMService.java @ 2100:2f5cb58e662e
Introduced new output type 'map'.
flys-artifacts/trunk@3654 c6561f87-3c4e-4783-a992-168aeb5c3f6f
author | Raimund Renkert <raimund.renkert@intevation.de> |
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date | Wed, 11 Jan 2012 14:32:50 +0000 |
parents | e0b081105a82 |
children | f021080cb409 |
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package de.intevation.flys.artifacts.services; import de.intevation.artifacts.CallMeta; import de.intevation.artifacts.GlobalContext; import de.intevation.artifacts.common.utils.XMLUtils; import de.intevation.flys.artifacts.cache.CacheFactory; import de.intevation.flys.backend.SessionHolder; import de.intevation.flys.model.CrossSection; import de.intevation.flys.model.CrossSectionLine; import java.util.AbstractMap; import java.util.ArrayDeque; import java.util.Deque; import java.util.List; import java.util.Map; import java.util.NavigableMap; import java.util.concurrent.ConcurrentSkipListMap; import net.sf.ehcache.Cache; import org.apache.log4j.Logger; import org.hibernate.Query; import org.hibernate.Session; import org.w3c.dom.Document; import org.w3c.dom.Element; import org.w3c.dom.NodeList; /** * Service to find the next/previous km (measurement) of cross sections. * Looking at the query for a single cross-section id at a single km, the * service does the following: * * It returns the km itself if a measurement at that km was found and * the N nearest other measurement points in both directions. * * That means, you can pass N=0 to find out whether a measurement at given km * exists. * * If less than N neighbours exist in one direction, less are delivered * (e.g. given measurements at [0,2,3,4,5,7,8,9] a query for km=8, N=3 will * result in [4,5,7,8,9]). */ public class CrossSectionKMService extends FLYSService { private static Logger logger = Logger.getLogger(CrossSectionKMService.class); public static final String CACHE_NAME = "cross-section-kms"; /** Trivial constructor. */ public CrossSectionKMService() { } /** * @param data */ @Override public Document doProcess( Document data, GlobalContext globalContext, CallMeta callMeta ) { logger.debug("CrossSectionKMService.doProcess"); NodeList crossSectionNodes = data.getElementsByTagName("art:cross-section"); Cache cache = CacheFactory.getCache(CACHE_NAME); Document document = XMLUtils.newDocument(); Element all = document.createElement("cross-sections"); for (int i = 0, CS = crossSectionNodes.getLength(); i < CS; ++i) { Element crossSectionElement = (Element)crossSectionNodes.item(i); String idString = crossSectionElement.getAttribute("id"); String kmString = crossSectionElement.getAttribute("km"); String neighborsString = crossSectionElement.getAttribute("n"); if (idString.length() == 0 || kmString.length() == 0) { logger.debug("missing attributes in cross-section element"); continue; } double km; Integer crossSectionId; int N = 2; try { km = Double.parseDouble(kmString); crossSectionId = Integer.valueOf(idString); if (neighborsString.length() > 0) { N = Integer.parseInt(neighborsString); } } catch (NumberFormatException nfe) { logger.debug("converting number failed", nfe); continue; } NavigableMap<Double, Integer> map; if (cache == null) { map = getUncached(crossSectionId); } else { net.sf.ehcache.Element element = cache.get(crossSectionId); if (element == null) { map = getUncached(crossSectionId); if (map != null) { element = new net.sf.ehcache.Element( crossSectionId, map); cache.put(element); } } else { map = (NavigableMap<Double, Integer>)element.getValue(); } } if (map == null) { logger.debug("cannot find cross section " + crossSectionId); continue; } Deque<Map.Entry<Double, Integer>> result = nearestNeighbors(map, km, N); if (!result.isEmpty()) { Element csE = document.createElement("cross-section"); csE.setAttribute("id", idString); for (Map.Entry<Double, Integer> entry: result) { Element lineE = document.createElement("line"); lineE.setAttribute( "line-id", String.valueOf(entry.getValue())); lineE.setAttribute( "km", String.valueOf(entry.getKey())); csE.appendChild(lineE); } all.appendChild(csE); } } document.appendChild(all); return document; } /** * @param km the kilometer from which to start searching for other * measurements * @param N number of neighboring measurements to find. */ public static Deque<Map.Entry<Double, Integer>> nearestNeighbors( NavigableMap<Double, Integer> map, double km, int N ) { Deque<Map.Entry<Double, Integer>> result = new ArrayDeque<Map.Entry<Double, Integer>>(2*N); if(map.get(km) != null) { result.add(new AbstractMap.SimpleEntry<Double, Integer>(km,map.get(km))); } int i = 0; for (Map.Entry<Double, Integer> entry: map.headMap(km, false).descendingMap().entrySet()) { if (i++ >= N) { break; } result.addFirst(entry); } i = 0; for (Map.Entry<Double, Integer> entry: map.tailMap(km, false).entrySet()) { if (i++ >= N) { break; } result.addLast(entry); } return result; } /** * @param crossSectionId id of queried cross-section (in db). * @return Mapping from kilometer to db-id. */ public static NavigableMap<Double, Integer> getUncached( Integer crossSectionId ) { NavigableMap<Double, Integer> result = new ConcurrentSkipListMap<Double, Integer>(); Session session = SessionHolder.HOLDER.get(); Query query = session.createQuery( "from CrossSection where id=:id"); query.setParameter("id", crossSectionId); List<CrossSection> crossSections = query.list(); if (crossSections.isEmpty()) { return null; } CrossSection crossSection = crossSections.get(0); List<CrossSectionLine> lines = crossSection.getLines(); for (CrossSectionLine line: lines) { Double km = line.getKm().doubleValue(); Integer id = line.getId(); result.put(km, id); } return result; } } // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :