Feat: Implement in-memory and fallback of database

Adds the handling and creation of the embedded database in RAM, which is
used for the in-memory and fallback modes.

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

 package de.hft.stuttgart.citydoctor2.database;
 
 import java.io.File;
+import java.util.StringJoiner;
 
 /**
  * Record containing the configuration parameters for the setup of the embedded database
@@ -20,8 +21,10 @@ import java.io.File;
 public record EmbeddedDatabaseConfiguration(String databaseName, String databaseDirectory, int connectionPoolSize,
                                             boolean inMemoryMode, boolean attemptFallback, boolean debugMode, boolean tempFileMode) {
 
-    private static final String IN_MEMORY_PREFIX= "mem:";
-    private static final String AUTO_SERVER_PARAMETER = ";AUTO_SERVER=TRUE";
+    private static final String IN_MEMORY_PREFIX = "mem:";
+    private static final String JDBC_DRIVER_PREFIX = "jdbc:h2:";
+    private static final String AUTO_SERVER_PARAMETER = "AUTO_SERVER=TRUE";
+    private static final String KEEP_ALIVE_PARAMETER = "DB_CLOSE_DELAY=-1";
     private static final String FILE_PREFIX = "file://";
     /**
      * Instantiates the default configuration for the embedded database.
@@ -36,20 +39,31 @@ public record EmbeddedDatabaseConfiguration(String databaseName, String database
                 true, true, true, false);
     }
 
+    public String wrapUrlWithH2JdbcDriver(String Url){
+        return JDBC_DRIVER_PREFIX + Url + getH2ParametersSuffix();
+    }
+
     public String getInMemoryH2Url() {
-        return IN_MEMORY_PREFIX + databaseName;
+        return wrapUrlWithH2JdbcDriver(IN_MEMORY_PREFIX + databaseName);
+    }
+
+    public String getFallbackH2Url(){
+        return getInMemoryH2Url() + ";" + KEEP_ALIVE_PARAMETER;
     }
 
     public String getH2FileUrl(){
-        return FILE_PREFIX + databaseDirectory + databaseName;
+        return wrapUrlWithH2JdbcDriver(databaseDirectory + databaseName);
     }
 
     public String getH2ParametersSuffix(){
+        StringJoiner joiner  = new StringJoiner(";",";","");
         if (debugMode){
-            return AUTO_SERVER_PARAMETER;
-        } else {
-            return ";";
+            joiner.add(AUTO_SERVER_PARAMETER);
+        }
+        if (inMemoryMode){
+            joiner.add(KEEP_ALIVE_PARAMETER);
         }
+        return joiner.toString();
     }
 
 }

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

@@ -14,10 +14,9 @@ import org.apache.commons.lang3.SerializationException;
 import org.apache.commons.lang3.SerializationUtils;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
-import org.h2gis.functions.factory.H2GISDBFactory;
 import org.h2gis.utilities.wrapper.DataSourceWrapper;
+import org.h2gis.functions.factory.H2GISFunctions;
 
-import javax.sql.DataSource;
 import java.io.ByteArrayInputStream;
 import java.io.File;
 import java.io.IOException;
@@ -26,6 +25,7 @@ import java.io.InvalidClassException;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.sql.Connection;
+import java.sql.DriverManager;
 import java.sql.PreparedStatement;
 import java.sql.ResultSet;
 import java.sql.SQLException;
@@ -41,20 +41,21 @@ public class EmbeddedDatabaseHandler {
     private static final Logger logger = LogManager.getLogger(EmbeddedDatabaseHandler.class);
     private final EmbeddedDatabaseConfiguration config;
     private DataSourceWrapper dataSource;
-    private File tempLoc = null;
+    private File tempFileDBLocation = null;
 
     public EmbeddedDatabaseHandler(EmbeddedDatabaseConfiguration dbConfig){
         config = dbConfig;
         String jdbcUrl;
         try {
             if (config.inMemoryMode()) {
-                jdbcUrl = createEmbeddedDataBase(config.getInMemoryH2Url());
+                jdbcUrl = setupInMemoryDataBase(config.getInMemoryH2Url());
             } else if (config.tempFileMode()){
                 Path tmpDir = Files.createTempDirectory(config.databaseDirectory());
                 tmpDir.toFile().deleteOnExit();
-                String tempFileUrl = tmpDir.resolve(config.databaseName()).toFile().getAbsolutePath();
-                jdbcUrl = createEmbeddedDataBase(tempFileUrl);
-                tempLoc = new File(tempFileUrl);
+                String tempFileUrl = tmpDir.resolve(config.databaseName()).toFile().getCanonicalPath();
+                jdbcUrl = createEmbeddedDataBase(config.wrapUrlWithH2JdbcDriver(tempFileUrl));
+                tempFileDBLocation = new File(tempFileUrl+".mv.db");
+                tempFileDBLocation.deleteOnExit();
             } else {
                 jdbcUrl = createEmbeddedDataBase(config.getH2FileUrl());
             }
@@ -66,7 +67,7 @@ public class EmbeddedDatabaseHandler {
             if (config.attemptFallback()){
                 logger.info("Attempting fallback to in-memory database");
                 try {
-                    jdbcUrl = createEmbeddedDataBase(config.getInMemoryH2Url());
+                    jdbcUrl = setupInMemoryDataBase(config.getFallbackH2Url());
                 } catch (Exception e1) {
                     throw new EmbeddedDatabaseHandlerException("Fallback to in-memory database failed, embedded database could not be created", e1);
                 }
@@ -93,15 +94,26 @@ public class EmbeddedDatabaseHandler {
     }
 
     private String createEmbeddedDataBase(String dbUrl) throws SQLException {
-        DataSource source = H2GISDBFactory.createDataSource(dbUrl,
-                true, config.getH2ParametersSuffix());
-        try (Connection con = source.getConnection()) {
+//        DataSource source = H2GISDBFactory.createDataSource("file://"+dbUrl,
+//                true, config.getH2ParametersSuffix());
+//        try (Connection con = source.getConnection()) {
+//            return con.getMetaData().getURL();
+//        }
+        try (Connection con = DriverManager.getConnection(dbUrl,"sa","sa")){
+            H2GISFunctions.load(con);
             return con.getMetaData().getURL();
         }
     }
 
-    public File getTempLoc(){
-        return this.tempLoc;
+    private String setupInMemoryDataBase(String dbUrl) throws SQLException{
+        try (Connection con = DriverManager.getConnection(dbUrl,"sa","sa")){
+            H2GISFunctions.load(con);
+            return con.getMetaData().getURL();
+        }
+    }
+
+    public File getTempFileDBLocation(){
+        return this.tempFileDBLocation;
     }
 
 

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

@@ -16,7 +16,6 @@ import de.hft.stuttgart.citydoctor2.parser.CityGmlParser;
 import de.hft.stuttgart.citydoctor2.parser.InvalidGmlFileException;
 import de.hft.stuttgart.citydoctor2.parser.ParserConfiguration;
 import org.citygml4j.core.model.building.AbstractBuilding;
-import org.junit.Before;
 import org.junit.Test;
 import org.mockito.Mockito;
 
@@ -33,37 +32,38 @@ import static org.junit.Assert.fail;
 public class EmbeddedDataBaseHandlerTest {
 
     private EmbeddedDatabaseHandler handler = new EmbeddedDatabaseHandler(new EmbeddedDatabaseConfiguration());
-    @Before
-    public void resetDatabase() {
-        try {
-            handler.setupFeaturesTable();
-        } catch (Exception e) {
-            fail(e.getMessage());
-        }
-    }
-    //TODO: FIX Test failures
+
     @Test
     public void testTempFileConfiguration(){
         EmbeddedDatabaseConfiguration tempFileconfig = new EmbeddedDatabaseConfiguration("database",
                 "inTempConfig",1, false,false,
                 false,true);
-        assertNull(handler.getTempLoc());
         EmbeddedDatabaseHandler tempHandler = new EmbeddedDatabaseHandler(tempFileconfig);
-        assertTrue(tempHandler.getTempLoc().exists());
+        assertTrue(tempHandler.getTempFileDBLocation().exists());
 
     }
 
     @Test
-    public void testInMemoryConfiguration(){
+    public void testInMemoryConfiguration() throws CityGmlParseException, InvalidGmlFileException {
         EmbeddedDatabaseConfiguration inMemoryConfig = new EmbeddedDatabaseConfiguration("database",
                 "irrelevant",1, true,false,
                 false,false);
         EmbeddedDatabaseHandler memHandler = new EmbeddedDatabaseHandler(inMemoryConfig);
-        assertFalse(memHandler.getTempLoc().exists());
+        assertNull(memHandler.getTempFileDBLocation());
+        ParserConfiguration config = new ParserConfiguration(8, false);
+        CityDoctorModel model = CityGmlParser.nestedCityGmlFileParse("src/test/resources/SimpleSolid_SrefBS.gml", config);
+        Building b = model.getBuildings().toList().get(0);
+        assertEquals(0, memHandler.getFeatureCount());
+        memHandler.marshallCityObject(b);
+        assertEquals(1, memHandler.getFeatureCount());
+        CityObject co = memHandler.unmarshallCityObject(b.getGmlId());
+        assertNotNull(co);
+        assertTrue(co instanceof Building);
     }
 
     @Test
     public void testGetBboxIntersectingObjects() {
+        handler.setupFeaturesTable();
         Building b = new Building();
         Building b2 = new Building();
         b2.setGmlObject(Mockito.mock(AbstractBuilding.class));
@@ -144,6 +144,7 @@ public class EmbeddedDataBaseHandlerTest {
 
     @Test
     public void testGetBboxBufferIntersectingObjects() {
+        handler.setupFeaturesTable();
         Building b = new Building();
         Building b2 = new Building();
         b2.setGmlObject(Mockito.mock(AbstractBuilding.class));
@@ -230,6 +231,7 @@ public class EmbeddedDataBaseHandlerTest {
 
             Building b = model.getBuildings().toList().get(0);
             assertNotNull(b);
+            assertEquals(1, handler.getFeatureCount());
             handler.marshallCityObject(b);
             assertEquals(1, handler.getFeatureCount());