Refactor: Implement CityObjectCache with Caffeine

CityDoctorParent/CityDoctorModel/src/main/java/de/hft/stuttgart/citydoctor2/database/CityObjectCache.java

 package de.hft.stuttgart.citydoctor2.database;
 
+import com.github.benmanes.caffeine.cache.Caffeine;
+import com.github.benmanes.caffeine.cache.LoadingCache;
 import de.hft.stuttgart.citydoctor2.datastructure.CityObject;
 import de.hft.stuttgart.citydoctor2.datastructure.GmlId;
 import de.hft.stuttgart.citydoctor2.utils.Pair;
@@ -12,57 +14,35 @@ import java.util.concurrent.ConcurrentHashMap;
 
 
 /**
- * Soft-reference cache for
+ * Cache for CityObjects
  */
 public class CityObjectCache {
-    private final Map<GmlId, SoftReference<CityObject>> cache = new ConcurrentHashMap<>();
+    private final LoadingCache<GmlId, CityObject> cache;
 
-    public void put(GmlId id, CityObject cityObject) {
-        cache.put(id, new SoftReference<>(cityObject));
-    }
 
-    public void cache(List<? extends CityObject> objects) {
+    public CityObjectCache() {
+        cache = Caffeine.newBuilder().maximumSize(1000).build(DatabaseHandler::unmarshallCityObject);
+    }
 
+    public void put(CityObject cityObject) {
+        DatabaseHandler.marshallCityObject(cityObject);
+        cache.put(cityObject.getGmlId(), cityObject);
     }
 
     public CityObject get(GmlId id) {
-        SoftReference<CityObject> ref = cache.get(id);
-        if (ref == null) {
-            return null;
-        }
-        CityObject cityObject = ref.get();
-        if (cityObject == null) {
-            cityObject = DatabaseHandler.unmarshallCityObject(id);
-            if (cityObject == null) {
-                cache.remove(id);
-            } else {
-                this.put(id, cityObject);
-            }
-        }
-        return cityObject;
+        return  cache.get(id);
     }
 
-    public static List<Pair<GmlId, List<GmlId>>> getCollidingObjectsList() {
-        List<Pair<GmlId, List<GmlId>>> collidingObjects = new ArrayList<>();
-        for (GmlId id : DatabaseHandler.getAllGmlIds()) {
-            List<GmlId> collidingIds = DatabaseHandler.getBBoxIntersectingObjects(id);
-            if (collidingIds != null && !collidingIds.isEmpty()) {
-                collidingObjects.add(new Pair<>(id, collidingIds));
-            }
+    public List<CityObject> get(List<GmlId> ids) {
+        List<CityObject> features = new ArrayList<>();
+        for (GmlId id : ids) {
+            features.add(cache.get(id));
         }
-        return collidingObjects;
+        return features;
     }
 
-    public void remove(GmlId id) {
-        cache.remove(id);
-    }
 
-    public void clear() {
-        cache.clear();
-    }
 
-    public int size() {
-        return cache.size();
-    }
+
 }
 

CityDoctorParent/CityDoctorModel/src/test/java/de/hft/stuttgart/citydoctor2/database/CityObjectCacheTest.java

+package de.hft.stuttgart.citydoctor2.database;
+
+import de.hft.stuttgart.citydoctor2.datastructure.Building;
+import de.hft.stuttgart.citydoctor2.datastructure.GeometryTestUtils;
+import de.hft.stuttgart.citydoctor2.datastructure.GeometryType;
+import de.hft.stuttgart.citydoctor2.datastructure.Lod;
+import org.citygml4j.core.model.building.AbstractBuilding;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.fail;
+import static org.mockito.Mockito.mock;
+
+public class CityObjectCacheTest {
+
+    @BeforeClass
+    public static void setUpBeforeClass() {
+        DatabaseHandler.setupDatabase();
+    }
+
+    @Before
+    public void resetDatabase() {
+        try {
+            DatabaseHandler.setupFeaturesTable();
+        } catch (Exception e) {
+            fail(e.getMessage());
+        }
+    }
+
+    @Test
+    public void testPut(){
+        Building b = new Building();
+        b.setGmlObject(mock(AbstractBuilding.class));
+        b.addGeometry(GeometryTestUtils.createDummyGeometry(GeometryType.SOLID, Lod.LOD0));
+
+        assertEquals(0, DatabaseHandler.getFeatureCount());
+        CityObjectCache cache = new CityObjectCache();
+        cache.put(b);
+        assertEquals(1, DatabaseHandler.getFeatureCount());
+    }
+
+
+}