Generalize script-based DB initialization and add R2DBC initializer

See gh-24741

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/jdbc/init/DataSourceScriptDatabaseInitializer.java

@@ -0,0 +1,75 @@
+/*
+ * Copyright 2012-2021 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.jdbc.init;
+
+import java.nio.charset.Charset;
+import java.util.List;
+
+import javax.sql.DataSource;
+
+import org.springframework.beans.factory.InitializingBean;
+import org.springframework.boot.sql.init.AbstractScriptDatabaseInitializer;
+import org.springframework.boot.sql.init.DatabaseInitializationSettings;
+import org.springframework.core.io.Resource;
+import org.springframework.jdbc.datasource.init.DatabasePopulatorUtils;
+import org.springframework.jdbc.datasource.init.ResourceDatabasePopulator;
+
+/**
+ * {@link InitializingBean} that performs {@link DataSource} initialization using schema
+ * (DDL) and data (DML) scripts.
+ *
+ * @author Andy Wilkinson
+ * @since 2.5.0
+ */
+public class DataSourceScriptDatabaseInitializer extends AbstractScriptDatabaseInitializer {
+
+	private final DataSource dataSource;
+
+	/**
+	 * Creates a new {@link DataSourceScriptDatabaseInitializer} that will initialize the
+	 * given {@code DataSource} using the given settings.
+	 * @param dataSource data source to initialize
+	 * @param settings initialization settings
+	 */
+	public DataSourceScriptDatabaseInitializer(DataSource dataSource, DatabaseInitializationSettings settings) {
+		super(settings);
+		this.dataSource = dataSource;
+	}
+
+	/**
+	 * Returns the {@code DataSource} that will be initialized.
+	 * @return the initialization data source
+	 */
+	protected final DataSource getDataSource() {
+		return this.dataSource;
+	}
+
+	@Override
+	protected void runScripts(List<Resource> resources, boolean continueOnError, String separator, Charset encoding) {
+		ResourceDatabasePopulator populator = new ResourceDatabasePopulator();
+		populator.setContinueOnError(continueOnError);
+		populator.setSeparator(separator);
+		if (encoding != null) {
+			populator.setSqlScriptEncoding(encoding.name());
+		}
+		for (Resource resource : resources) {
+			populator.addScript(resource);
+		}
+		DatabasePopulatorUtils.execute(populator, this.dataSource);
+	}
+
+}

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/jdbc/init/DataSourceScriptDatabaseInitializerDetector.java

@@ -23,15 +23,16 @@ import org.springframework.boot.jdbc.init.dependency.AbstractBeansOfTypeDataSour
 import org.springframework.boot.jdbc.init.dependency.DataSourceInitializerDetector;
 
 /**
- * A {@link DataSourceInitializerDetector} for {@link ScriptDataSourceInitializer}.
+ * A {@link DataSourceInitializerDetector} for
+ * {@link DataSourceScriptDatabaseInitializer}.
  *
  * @author Andy Wilkinson
  */
-class ScriptDataSourceInitializerDetector extends AbstractBeansOfTypeDataSourceInitializerDetector {
+class DataSourceScriptDatabaseInitializerDetector extends AbstractBeansOfTypeDataSourceInitializerDetector {
 
 	@Override
 	protected Set<Class<?>> getDataSourceInitializerBeanTypes() {
-		return Collections.singleton(ScriptDataSourceInitializer.class);
+		return Collections.singleton(DataSourceScriptDatabaseInitializer.class);
 	}
 
 }

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/jdbc/init/package-info.java

@@ -15,6 +15,7 @@
  */
 
 /**
- * Support for initializaton of a JDBC {@code DataSource}.
+ * Support for initializaton of an SQL database using a JDBC {@link javax.sql.DataSource
+ * DataSource}.
  */
 package org.springframework.boot.jdbc.init;

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/r2dbc/init/R2dbcScriptDatabaseInitializer.java

@@ -0,0 +1,68 @@
+/*
+ * Copyright 2012-2021 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.r2dbc.init;
+
+import java.nio.charset.Charset;
+import java.util.List;
+
+import io.r2dbc.spi.ConnectionFactory;
+
+import org.springframework.beans.factory.InitializingBean;
+import org.springframework.boot.sql.init.AbstractScriptDatabaseInitializer;
+import org.springframework.boot.sql.init.DatabaseInitializationSettings;
+import org.springframework.core.io.Resource;
+import org.springframework.r2dbc.connection.init.ResourceDatabasePopulator;
+
+/**
+ * An {@link InitializingBean} that initializes a database represented by an R2DBC
+ * {@link ConnectionFactory}.
+ *
+ * @author Andy Wilkinson
+ * @since 2.5.0
+ */
+public class R2dbcScriptDatabaseInitializer extends AbstractScriptDatabaseInitializer {
+
+	private final ConnectionFactory connectionFactory;
+
+	/**
+	 * Creates a new {@code R2dbcScriptDatabaseInitializer} that will initialize the
+	 * database recognized by the given {@code connectionFactory} using the given
+	 * {@code settings}.
+	 * @param connectionFactory connectionFactory for the database
+	 * @param settings initialization settings
+	 */
+	public R2dbcScriptDatabaseInitializer(ConnectionFactory connectionFactory,
+			DatabaseInitializationSettings settings) {
+		super(settings);
+		this.connectionFactory = connectionFactory;
+	}
+
+	@Override
+	protected void runScripts(List<Resource> scripts, boolean continueOnError, String separator, Charset encoding) {
+		ResourceDatabasePopulator populator = new ResourceDatabasePopulator();
+		populator.setContinueOnError(continueOnError);
+		populator.setSeparator(separator);
+		if (encoding != null) {
+			populator.setSqlScriptEncoding(encoding.name());
+		}
+		for (Resource script : scripts) {
+			populator.addScript(script);
+		}
+		populator.populate(this.connectionFactory).block();
+	}
+
+}

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/r2dbc/init/package-info.java

@@ -0,0 +1,21 @@
+/*
+ * Copyright 2012-2021 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * Support for initializaton of an SQL database using an R2DBC
+ * {@link io.r2dbc.spi.ConnectionFactory ConnectionFactory}.
+ */
+package org.springframework.boot.r2dbc.init;

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/sql/init/AbstractScriptDatabaseInitializer.java

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package org.springframework.boot.jdbc.init;
+package org.springframework.boot.sql.init;
 
 import java.io.IOException;
 import java.nio.charset.Charset;
@@ -23,54 +23,38 @@ import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 
-import javax.sql.DataSource;
-
 import org.springframework.beans.factory.InitializingBean;
 import org.springframework.context.ResourceLoaderAware;
 import org.springframework.core.io.Resource;
 import org.springframework.core.io.ResourceLoader;
 import org.springframework.core.io.support.ResourcePatternResolver;
 import org.springframework.core.io.support.ResourcePatternUtils;
-import org.springframework.jdbc.datasource.init.DatabasePopulatorUtils;
-import org.springframework.jdbc.datasource.init.ResourceDatabasePopulator;
 import org.springframework.util.CollectionUtils;
 
 /**
- * {@link InitializingBean} that performs {@link DataSource} initialization using schema
- * (DDL) and data (DML) scripts.
+ * Base class for an {@link InitializingBean} that performs SQL database initialization
+ * using schema (DDL) and data (DML) scripts.
  *
  * @author Andy Wilkinson
  * @since 2.5.0
  */
-public class ScriptDataSourceInitializer implements ResourceLoaderAware, InitializingBean {
+public abstract class AbstractScriptDatabaseInitializer implements ResourceLoaderAware, InitializingBean {
 
 	private static final String OPTIONAL_LOCATION_PREFIX = "optional:";
 
-	private final DataSource dataSource;
-
-	private final DataSourceInitializationSettings settings;
+	private final DatabaseInitializationSettings settings;
 
 	private volatile ResourceLoader resourceLoader;
 
 	/**
-	 * Creates a new {@link ScriptDataSourceInitializer} that will initialize the given
-	 * {@code DataSource} using the given settings.
-	 * @param dataSource data source to initialize
+	 * Creates a new {@link AbstractScriptDatabaseInitializer} that will initialize the
+	 * database using the given settings.
 	 * @param settings initialization settings
 	 */
-	public ScriptDataSourceInitializer(DataSource dataSource, DataSourceInitializationSettings settings) {
-		this.dataSource = dataSource;
+	protected AbstractScriptDatabaseInitializer(DatabaseInitializationSettings settings) {
 		this.settings = settings;
 	}
 
-	/**
-	 * Returns the {@code DataSource} that will be initialized.
-	 * @return the initialization data source
-	 */
-	protected final DataSource getDataSource() {
-		return this.dataSource;
-	}
-
 	@Override
 	public void setResourceLoader(ResourceLoader resourceLoader) {
 		this.resourceLoader = resourceLoader;
@@ -148,18 +132,8 @@ public class ScriptDataSourceInitializer implements ResourceLoaderAware, Initial
 				this.settings.getEncoding());
 	}
 
-	protected void runScripts(List<Resource> resources, boolean continueOnError, String separator, Charset encoding) {
-		ResourceDatabasePopulator populator = new ResourceDatabasePopulator();
-		populator.setContinueOnError(continueOnError);
-		populator.setSeparator(separator);
-		if (encoding != null) {
-			populator.setSqlScriptEncoding(encoding.name());
-		}
-		for (Resource resource : resources) {
-			populator.addScript(resource);
-		}
-		DatabasePopulatorUtils.execute(populator, this.dataSource);
-	}
+	protected abstract void runScripts(List<Resource> resources, boolean continueOnError, String separator,
+			Charset encoding);
 
 	private static class ScriptLocationResolver {
 

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/sql/init/DatabaseInitializationSettings.java

@@ -14,20 +14,18 @@
  * limitations under the License.
  */
 
-package org.springframework.boot.jdbc.init;
+package org.springframework.boot.sql.init;
 
 import java.nio.charset.Charset;
 import java.util.List;
 
-import javax.sql.DataSource;
-
 /**
- * Settings for initializing a database using a JDBC {@link DataSource}.
+ * Settings for initializing an SQL database.
  *
  * @author Andy Wilkinson
  * @since 2.5.0
  */
-public class DataSourceInitializationSettings {
+public class DatabaseInitializationSettings {
 
 	private List<String> schemaLocations;
 

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/sql/init/package-info.java

@@ -0,0 +1,20 @@
+/*
+ * Copyright 2012-2021 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * Support for initializaton of an SQL database.
+ */
+package org.springframework.boot.sql.init;

spring-boot-project/spring-boot/src/main/resources/META-INF/spring.factories

@@ -82,7 +82,7 @@ org.springframework.boot.diagnostics.LoggingFailureAnalysisReporter
 # DataSource Initializer Detectors
 org.springframework.boot.jdbc.init.dependency.DataSourceInitializerDetector=\
 org.springframework.boot.flyway.FlywayDataSourceInitializerDetector,\
-org.springframework.boot.jdbc.init.ScriptDataSourceInitializerDetector,\
+org.springframework.boot.jdbc.init.DataSourceScriptDatabaseInitializerDetector,\
 org.springframework.boot.liquibase.LiquibaseDataSourceInitializerDetector,\
 org.springframework.boot.orm.jpa.JpaDataSourceInitializerDetector
 

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/jdbc/init/DataSourceScriptDatabaseInitializerTests.java

@@ -0,0 +1,55 @@
+/*
+ * Copyright 2012-2021 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.jdbc.init;
+
+import java.util.UUID;
+
+import com.zaxxer.hikari.HikariDataSource;
+import org.junit.jupiter.api.AfterEach;
+
+import org.springframework.boot.jdbc.DataSourceBuilder;
+import org.springframework.boot.sql.init.AbstractScriptDatabaseInitializer;
+import org.springframework.boot.sql.init.AbstractScriptDatabaseInitializerTests;
+import org.springframework.boot.sql.init.DatabaseInitializationSettings;
+import org.springframework.jdbc.core.JdbcTemplate;
+
+/**
+ * Tests for {@link DataSourceScriptDatabaseInitializer}.
+ *
+ * @author Andy Wilkinson
+ */
+class DataSourceScriptDatabaseInitializerTests extends AbstractScriptDatabaseInitializerTests {
+
+	private final HikariDataSource dataSource = DataSourceBuilder.create().type(HikariDataSource.class)
+			.url("jdbc:h2:mem:" + UUID.randomUUID()).build();
+
+	@AfterEach
+	void closeDataSource() {
+		this.dataSource.close();
+	}
+
+	@Override
+	protected AbstractScriptDatabaseInitializer createInitializer(DatabaseInitializationSettings settings) {
+		return new DataSourceScriptDatabaseInitializer(this.dataSource, settings);
+	}
+
+	@Override
+	protected int numberOfRows(String sql) {
+		return new JdbcTemplate(this.dataSource).queryForObject(sql, Integer.class);
+	}
+
+}

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/r2dbc/init/R2dbcScriptDatabaseInitializerTests.java

@@ -0,0 +1,51 @@
+/*
+ * Copyright 2012-2021 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.r2dbc.init;
+
+import java.util.UUID;
+
+import io.r2dbc.spi.ConnectionFactory;
+
+import org.springframework.boot.r2dbc.ConnectionFactoryBuilder;
+import org.springframework.boot.sql.init.AbstractScriptDatabaseInitializer;
+import org.springframework.boot.sql.init.AbstractScriptDatabaseInitializerTests;
+import org.springframework.boot.sql.init.DatabaseInitializationSettings;
+import org.springframework.r2dbc.core.DatabaseClient;
+
+/**
+ * Tests for {@link R2dbcScriptDatabaseInitializer}.
+ *
+ * @author Andy Wilkinson
+ */
+class R2dbcScriptDatabaseInitializerTests extends AbstractScriptDatabaseInitializerTests {
+
+	private final ConnectionFactory connectionFactory = ConnectionFactoryBuilder
+			.withUrl("r2dbc:h2:mem:///" + UUID.randomUUID() + "?options=DB_CLOSE_DELAY=-1;DB_CLOSE_ON_EXIT=FALSE")
+			.build();
+
+	@Override
+	protected AbstractScriptDatabaseInitializer createInitializer(DatabaseInitializationSettings settings) {
+		return new R2dbcScriptDatabaseInitializer(this.connectionFactory, settings);
+	}
+
+	@Override
+	protected int numberOfRows(String sql) {
+		return DatabaseClient.create(this.connectionFactory).sql(sql).map((row, metadata) -> row.get(0)).first()
+				.map((number) -> ((Number) number).intValue()).block();
+	}
+
+}

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/sql/init/AbstractScriptDatabaseInitializerTests.java

@@ -14,105 +14,88 @@
  * limitations under the License.
  */
 
-package org.springframework.boot.jdbc.init;
+package org.springframework.boot.sql.init;
 
 import java.util.Arrays;
-import java.util.UUID;
 
-import com.zaxxer.hikari.HikariDataSource;
-import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.Test;
 
-import org.springframework.boot.jdbc.DataSourceBuilder;
 import org.springframework.dao.DataAccessException;
-import org.springframework.jdbc.core.JdbcTemplate;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
 import static org.assertj.core.api.Assertions.assertThatIllegalStateException;
 
 /**
- * Tests for {@link ScriptDataSourceInitializer}.
+ * Base class for testing {@link AbstractScriptDatabaseInitializer} implementations.
  *
  * @author Andy Wilkinson
  */
-class ScriptDataSourceInitializerTests {
-
-	private final HikariDataSource dataSource = DataSourceBuilder.create().type(HikariDataSource.class)
-			.url("jdbc:h2:mem:" + UUID.randomUUID()).build();
-
-	@AfterEach
-	void closeDataSource() {
-		this.dataSource.close();
-	}
+public abstract class AbstractScriptDatabaseInitializerTests {
 
 	@Test
 	void whenDatabaseIsInitializedThenSchemaAndDataScriptsAreApplied() {
-		DataSourceInitializationSettings settings = new DataSourceInitializationSettings();
+		DatabaseInitializationSettings settings = new DatabaseInitializationSettings();
 		settings.setSchemaLocations(Arrays.asList("schema.sql"));
 		settings.setDataLocations(Arrays.asList("data.sql"));
-		ScriptDataSourceInitializer initializer = createInitializer(settings);
+		AbstractScriptDatabaseInitializer initializer = createInitializer(settings);
 		assertThat(initializer.initializeDatabase()).isTrue();
 		assertThat(numberOfRows("SELECT COUNT(*) FROM EXAMPLE")).isEqualTo(1);
 	}
 
 	@Test
 	void whenContinueOnErrorIsFalseThenInitializationFailsOnError() {
-		DataSourceInitializationSettings settings = new DataSourceInitializationSettings();
+		DatabaseInitializationSettings settings = new DatabaseInitializationSettings();
 		settings.setDataLocations(Arrays.asList("data.sql"));
-		ScriptDataSourceInitializer initializer = createInitializer(settings);
+		AbstractScriptDatabaseInitializer initializer = createInitializer(settings);
 		assertThatExceptionOfType(DataAccessException.class).isThrownBy(() -> initializer.initializeDatabase());
 	}
 
 	@Test
 	void whenContinueOnErrorIsTrueThenInitializationDoesNotFailOnError() {
-		DataSourceInitializationSettings settings = new DataSourceInitializationSettings();
+		DatabaseInitializationSettings settings = new DatabaseInitializationSettings();
 		settings.setContinueOnError(true);
 		settings.setDataLocations(Arrays.asList("data.sql"));
-		ScriptDataSourceInitializer initializer = createInitializer(settings);
+		AbstractScriptDatabaseInitializer initializer = createInitializer(settings);
 		assertThat(initializer.initializeDatabase()).isTrue();
 	}
 
 	@Test
 	void whenNoScriptsExistAtASchemaLocationThenInitializationFails() {
-		DataSourceInitializationSettings settings = new DataSourceInitializationSettings();
+		DatabaseInitializationSettings settings = new DatabaseInitializationSettings();
 		settings.setSchemaLocations(Arrays.asList("does-not-exist.sql"));
-		ScriptDataSourceInitializer initializer = createInitializer(settings);
+		AbstractScriptDatabaseInitializer initializer = createInitializer(settings);
 		assertThatIllegalStateException().isThrownBy(initializer::initializeDatabase)
 				.withMessage("No schema scripts found at location 'does-not-exist.sql'");
 	}
 
 	@Test
 	void whenNoScriptsExistAtADataLocationThenInitializationFails() {
-		DataSourceInitializationSettings settings = new DataSourceInitializationSettings();
+		DatabaseInitializationSettings settings = new DatabaseInitializationSettings();
 		settings.setDataLocations(Arrays.asList("does-not-exist.sql"));
-		ScriptDataSourceInitializer initializer = createInitializer(settings);
+		AbstractScriptDatabaseInitializer initializer = createInitializer(settings);
 		assertThatIllegalStateException().isThrownBy(initializer::initializeDatabase)
 				.withMessage("No data scripts found at location 'does-not-exist.sql'");
 	}
 
 	@Test
 	void whenNoScriptsExistAtAnOptionalSchemaLocationThenInitializationSucceeds() {
-		DataSourceInitializationSettings settings = new DataSourceInitializationSettings();
+		DatabaseInitializationSettings settings = new DatabaseInitializationSettings();
 		settings.setSchemaLocations(Arrays.asList("optional:does-not-exist.sql"));
-		ScriptDataSourceInitializer initializer = createInitializer(settings);
+		AbstractScriptDatabaseInitializer initializer = createInitializer(settings);
 		assertThat(initializer.initializeDatabase()).isFalse();
 	}
 
 	@Test
 	void whenNoScriptsExistAtAnOptionalDataLocationThenInitializationSucceeds() {
-		DataSourceInitializationSettings settings = new DataSourceInitializationSettings();
+		DatabaseInitializationSettings settings = new DatabaseInitializationSettings();
 		settings.setDataLocations(Arrays.asList("optional:does-not-exist.sql"));
-		ScriptDataSourceInitializer initializer = createInitializer(settings);
+		AbstractScriptDatabaseInitializer initializer = createInitializer(settings);
 		assertThat(initializer.initializeDatabase()).isFalse();
 	}
 
-	private ScriptDataSourceInitializer createInitializer(DataSourceInitializationSettings settings) {
-		return new ScriptDataSourceInitializer(this.dataSource, settings);
-	}
+	protected abstract AbstractScriptDatabaseInitializer createInitializer(DatabaseInitializationSettings settings);
 
-	private int numberOfRows(String sql) {
-		return new JdbcTemplate(this.dataSource).queryForObject(sql, Integer.class);
-	}
+	protected abstract int numberOfRows(String sql);
 
 }