Feat: Add basis for topology checks

CityDoctorParent/CityDoctorModel/src/main/java/de/hft/stuttgart/citydoctor2/check/RequirementType.java

@@ -28,6 +28,6 @@ package de.hft.stuttgart.citydoctor2.check;
  */
 public enum RequirementType {
 
-	GEOMETRY, SEMANTIC
+	GEOMETRY, SEMANTIC, TOPOLOGY
 
 }

CityDoctorParent/CityDoctorValidation/src/main/java/de/hft/stuttgart/citydoctor2/check/Checker.java

@@ -47,6 +47,7 @@ import java.util.concurrent.ThreadPoolExecutor;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicInteger;
 
+import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 import javax.xml.XMLConstants;
 import javax.xml.transform.Result;
@@ -59,6 +60,7 @@ import javax.xml.transform.dom.DOMSource;
 import javax.xml.transform.sax.SAXResult;
 import javax.xml.transform.stream.StreamSource;
 
+import de.hft.stuttgart.citydoctor2.checks.topology.TopologyCheck;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 
@@ -210,6 +212,7 @@ public class Checker {
             Future<SvrlContentHandler> handlerFuture =  executor.submit(schematronThread);
             executor.shutdown();
 
+            TopologyCheck.registerCache(model.getCache());
             checkCityModel(model, l);
             getSchematronResults(handlerFuture, l);
 
@@ -622,7 +625,7 @@ public class Checker {
         Map<CheckId, Map<String, String>> parameterMap = new HashMap<>();
         for (Entry<String, RequirementConfiguration> e : config.getRequirements().entrySet()) {
             de.hft.stuttgart.citydoctor2.check.Requirement req = Checks.getAvailableRequirements().get(e.getKey());
-            if (req == null) {
+            if (req == null && logger.isWarnEnabled()) {
                 logger.warn(Localization.getText("Checker.noCheckSatisfiesRequirement"),
                         e.getKey());
             } else {

CityDoctorParent/CityDoctorValidation/src/main/java/de/hft/stuttgart/citydoctor2/checks/topology/TopologyCheck.java

+package de.hft.stuttgart.citydoctor2.checks.topology;
+
+import de.hft.stuttgart.citydoctor2.check.Check;
+import de.hft.stuttgart.citydoctor2.check.RequirementType;
+import de.hft.stuttgart.citydoctor2.database.CityObjectCache;
+
+/** Topology checks are a specific subclass of checks which check conditions, constraints and requirements between
+ * different Features within the same CityModel. As such they require access to multiple CityObjects to run, necessitating
+ * access to the CityObject cache for efficient memory usage.
+ * <p>
+ * The following terms will be used in the documentation of topological checks:
+ * <ul>
+ *     <li>Subject: The Feature that is being checked
+ *     <li>Candidate(s): Other Features that are being checked against the subject. Candidates are selected via spatial
+ *     proximity, as Features that are too far away from the subject can't conflict topological requirements and can thus
+ *     be safely skipped by the checks.
+ * <ul/>
+ *
+ * <p/>
+ */
+public abstract class TopologyCheck extends Check {
+
+    protected static CityObjectCache registeredCache;
+
+    public static void registerCache(CityObjectCache cache){
+        registeredCache = cache;
+    }
+
+
+    @Override
+    public RequirementType getType() {
+        return RequirementType.TOPOLOGY;
+    }
+
+}