001 /**
002 * Copyright (C) 2007-2011, Jens Lehmann
003 *
004 * This file is part of DL-Learner.
005 *
006 * DL-Learner is free software; you can redistribute it and/or modify
007 * it under the terms of the GNU General Public License as published by
008 * the Free Software Foundation; either version 3 of the License, or
009 * (at your option) any later version.
010 *
011 * DL-Learner is distributed in the hope that it will be useful,
012 * but WITHOUT ANY WARRANTY; without even the implied warranty of
013 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
014 * GNU General Public License for more details.
015 *
016 * You should have received a copy of the GNU General Public License
017 * along with this program. If not, see <http://www.gnu.org/licenses/>.
018 */
019
020 package org.dllearner.kb.aquisitors;
021
022 import java.net.URI;
023 import java.util.SortedSet;
024 import java.util.TreeSet;
025
026 import org.apache.log4j.Logger;
027 import org.dllearner.utilities.datastructures.RDFNodeTuple;
028
029 /**
030 *
031 * Typed SPARQL query interface. The typing means that they all have the same
032 * input and the same output: They are fn: resource -> ( a | b ) where a
033 * normally is a predicate and b an object
034 *
035 * @author Sebastian Hellmann
036 *
037 */
038 public abstract class TupleAquisitor {
039
040
041 private static Logger logger = Logger.getLogger(TupleAquisitor.class);
042 protected final int NORMAL = 0;
043 protected final int CLASSES_FOR_INSTANCES = 1;
044 protected final int CLASS_INFORMATION = 2;
045
046 protected int mode = 0;
047 protected boolean uriDebugCheck = true;
048
049 public boolean dissolveBlankNodes = false;
050
051
052 /**
053 * TODO: this function is still used somewhere, but should be replaced
054 * @return
055 */
056 public boolean isDissolveBlankNodes(){
057 return dissolveBlankNodes;
058 }
059
060 public final SortedSet<RDFNodeTuple> getTupelForResource(String uri){
061 checkURIforValidity(uri);
062
063 try{
064 if (mode == NORMAL) {
065 return retrieveTupel(uri);
066 } else if(mode == CLASSES_FOR_INSTANCES){
067 return retrieveClassesForInstances(uri);
068 }else if(mode == CLASS_INFORMATION){
069 return retrieveTuplesForClassesOnly(uri);
070 }else{
071 throw new RuntimeException("undefined mode in aquisitor");
072 }
073 }catch(Exception e){
074 logger.warn("Caught exception in tupleaquisitor, ignoring it: "+e.toString());
075 return new TreeSet<RDFNodeTuple>();
076
077 }
078 }
079 public abstract SortedSet<RDFNodeTuple> retrieveTupel(String uri);
080 public abstract SortedSet<RDFNodeTuple> retrieveClassesForInstances(String uri);
081 public abstract SortedSet<RDFNodeTuple> retrieveTuplesForClassesOnly(String uri);
082 protected abstract void disambiguateBlankNodes(String uri, SortedSet<RDFNodeTuple> resultSet);
083 public abstract SortedSet<RDFNodeTuple> getBlankNode(int id);
084
085 /*private void setMode(int mode) {
086 this.mode = mode;
087 }*/
088
089 public int getMode() {
090 return mode;
091 }
092
093 public void setNextTaskToNormal(){mode = NORMAL;}
094 public void setNextTaskToClassesForInstances(){mode = CLASSES_FOR_INSTANCES;}
095 public void setNextTaskToClassInformation(){mode = CLASS_INFORMATION;}
096
097 protected boolean checkURIforValidity(String uri){
098 if(uriDebugCheck) return true;
099 try{
100 new URI(uri);
101 }catch (Exception e) {
102 logger.warn("Exception while validating uri: "+uri);
103 return false;
104 }
105 return true;
106 }
107 }
108
109