Refactor: Rework handling of DatabaseHandler returns

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

@@ -70,6 +70,10 @@ public class DatabaseHandler {
         }
     }
 
+    /**
+     * Saves a CityObject to the embedded database, updating an existing entry if it exists.
+     * @param co the CityObject
+     */
     public static void marshallCityObject(CityObject co) {
         try (Connection con = new ConnectionWrapper(H2GISDBFactory.openSpatialDataBase(DB_NAME))) {
             try (PreparedStatement ps = con.prepareStatement("MERGE INTO features VALUES (?, ?, ?, ?)")) {
@@ -91,6 +95,11 @@ public class DatabaseHandler {
         }
     }
 
+    /**
+     * Retrieves a CityObject from the embedded database.
+     * @param id the gmlId of the requested Feature
+     * @return the Feature, or null if no entry was found
+     */
     public static CityObject unmarshallCityObject(GmlId id) {
         try (Connection con = new ConnectionWrapper(H2GISDBFactory.openSpatialDataBase(DB_NAME))) {
             try (PreparedStatement ps = con.prepareStatement("SELECT gmlid, bbox, data, type FROM features WHERE gmlid = ?")) {
@@ -150,16 +159,22 @@ public class DatabaseHandler {
         return cos;
     }
 
-    public static List<CityObject> getBufferIntersectingObjects(CityObject co, double bufferSize) {
-        List<CityObject> intersectingObjects = new ArrayList<>();
+    public static List<GmlId> getBufferIntersectingObjects(CityObject co, double bufferSize) {
+        return getBufferIntersectingObjects(co.getGmlId(), bufferSize);
+    }
+
+    public static List<GmlId> getBufferIntersectingObjects(GmlId gmlID, double bufferSize) {
+        List<GmlId> intersectingObjects = new ArrayList<>();
         try (Connection con = new ConnectionWrapper(H2GISDBFactory.openSpatialDataBase(DB_NAME))) {
-            try (PreparedStatement ps = con.prepareStatement("SELECT gmlid, bbox, data, type FROM features AS tab1" +
+            try (PreparedStatement ps = con.prepareStatement("SELECT gmlid FROM features AS tab1" +
                     " WHERE ST_INTERSECTS(ST_BUFFER(tab1.bbox,?), (SELECT bbox FROM features WHERE gmlid = ?)) AND tab1.gmlid <> ?")) {
                 ps.setDouble(1, bufferSize);
-                ps.setString(2, co.getGmlId().toString());
-                ps.setString(3, co.getGmlId().toString());
+                ps.setString(2, gmlID.toString());
+                ps.setString(3, gmlID.toString());
                 ResultSet rs = ps.executeQuery();
-                intersectingObjects.addAll(retrieveCityObjects(rs));
+                while (rs.next()) {
+                    intersectingObjects.add(new GmlId(rs.getString("gmlid")));
+                }
             }
         } catch (SQLException e) {
             logger.error("Connection to database failed while trying to get buffer intersecting objects!");
@@ -168,22 +183,8 @@ public class DatabaseHandler {
         return intersectingObjects;
     }
 
-    public static List<CityObject> getBBoxIntersectingObjects(CityObject co) {
-        List<CityObject> intersectingObjects = new ArrayList<>();
-
-        try (Connection con = new ConnectionWrapper(H2GISDBFactory.openSpatialDataBase(DB_NAME))) {
-            try (PreparedStatement ps = con.prepareStatement("SELECT gmlid, bbox, data, type FROM features AS tab1" +
-                    " WHERE ST_INTERSECTS(tab1.bbox, (SELECT bbox FROM features WHERE gmlid = ?)) AND tab1.gmlid <> ?")) {
-                ps.setString(1, co.getGmlId().toString());
-                ps.setString(2, co.getGmlId().toString());
-                ResultSet rs = ps.executeQuery();
-                intersectingObjects.addAll(retrieveCityObjects(rs));
-            }
-        } catch (SQLException e) {
-            logger.error("Connection to database failed while trying to get bbox intersecting objects!");
-            logger.debug(e.getMessage());
-        }
-        return intersectingObjects;
+    public static List<GmlId> getBBoxIntersectingObjects(CityObject co) {
+        return getBBoxIntersectingObjects(co.getGmlId());
     }
 
     public static List<GmlId> getBBoxIntersectingObjects(GmlId id) {

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

@@ -7,6 +7,7 @@ import de.hft.stuttgart.citydoctor2.datastructure.ConcretePolygon;
 import de.hft.stuttgart.citydoctor2.datastructure.Geometry;
 import de.hft.stuttgart.citydoctor2.datastructure.GeometryTestUtils;
 import de.hft.stuttgart.citydoctor2.datastructure.GeometryType;
+import de.hft.stuttgart.citydoctor2.datastructure.GmlId;
 import de.hft.stuttgart.citydoctor2.datastructure.LinearRing;
 import de.hft.stuttgart.citydoctor2.datastructure.Lod;
 import de.hft.stuttgart.citydoctor2.datastructure.Vertex;
@@ -144,11 +145,13 @@ public class DataBaseHandlerTest {
         DatabaseHandler.marshallCityObject(b4);
         assertEquals(4, DatabaseHandler.getFeatureCount());
 
-        List<CityObject> objects = DatabaseHandler.getBBoxIntersectingObjects(b);
+        List<GmlId> objects = DatabaseHandler.getBBoxIntersectingObjects(b);
         assertEquals(1, objects.size());
         assertEquals(4, DatabaseHandler.getFeatureCount());
 
-        assertCityObjectEquality(b2, objects.get(0));
+        CityObject co = DatabaseHandler.unmarshallCityObject(objects.get(0));
+        assertNotNull(co);
+        assertCityObjectEquality(b2, co);
 
     }
 
@@ -223,11 +226,13 @@ public class DataBaseHandlerTest {
         DatabaseHandler.marshallCityObject(b4);
         assertEquals(4, DatabaseHandler.getFeatureCount());
 
-        List<CityObject> objects = DatabaseHandler.getBufferIntersectingObjects(b, Math.sqrt(2));
+        List<GmlId> objects = DatabaseHandler.getBufferIntersectingObjects(b, Math.sqrt(2));
         assertEquals(1, objects.size());
         assertEquals(4, DatabaseHandler.getFeatureCount());
 
-        assertCityObjectEquality(b2, objects.get(0));
+        CityObject co = DatabaseHandler.unmarshallCityObject(objects.get(0));
+        assertNotNull(co);
+        assertCityObjectEquality(b2, co);
 
     }