Allow customizations of embedded database connections

This commit allows EmbeddedDatabaseConfigurer instances to be further
customized if necessary. EmbeddedDatabaseBuilder has a way now to set
a DatabaseConfigurer rather than just a type to provide full control,
or customize an existing supported database type using the new
EmbeddedDatabaseConfigurers#customizeConfigurer callback.

Closes gh-21160

spring-jdbc/src/test/java/org/springframework/jdbc/datasource/embedded/EmbeddedDatabaseBuilderTests.java

@@ -121,6 +121,23 @@ class EmbeddedDatabaseBuilderTests {
 		});
 	}
 
+	@Test
+	void setTypeConfigurerToCustomH2() {
+		doTwice(() -> {
+			EmbeddedDatabase db = builder
+					.setDatabaseConfigurer(EmbeddedDatabaseConfigurers.customizeConfigurer(H2, defaultConfigurer ->
+							new EmbeddedDatabaseConfigurerDelegate(defaultConfigurer) {
+								@Override
+								public void configureConnectionProperties(ConnectionProperties properties, String databaseName) {
+									super.configureConnectionProperties(properties, databaseName);
+								}
+							}))
+					.addScripts("db-schema.sql", "db-test-data.sql")//
+					.build();
+			assertDatabaseCreatedAndShutdown(db);
+		});
+	}
+
 	@Test
 	void setTypeToDerbyAndIgnoreFailedDrops() {
 		doTwice(() -> {

spring-jdbc/src/test/java/org/springframework/jdbc/datasource/embedded/EmbeddedDatabaseFactoryTests.java

@@ -17,6 +17,7 @@
 package org.springframework.jdbc.datasource.embedded;
 
 import java.sql.Connection;
+import java.sql.SQLException;
 
 import org.junit.jupiter.api.Test;
 
@@ -25,11 +26,14 @@ import org.springframework.jdbc.datasource.init.DatabasePopulator;
 import static org.assertj.core.api.Assertions.assertThat;
 
 /**
+ * Tests for {@link EmbeddedDatabaseFactory}.
+ *
  * @author Keith Donald
+ * @author Stephane Nicoll
  */
 class EmbeddedDatabaseFactoryTests {
 
-	private EmbeddedDatabaseFactory factory = new EmbeddedDatabaseFactory();
+	private final EmbeddedDatabaseFactory factory = new EmbeddedDatabaseFactory();
 
 
 	@Test
@@ -41,6 +45,45 @@ class EmbeddedDatabaseFactoryTests {
 		db.shutdown();
 	}
 
+	@Test
+	void customizeConfigurerWithAnotherDatabaseName() throws SQLException {
+		this.factory.setDatabaseName("original-db-mame");
+		this.factory.setDatabaseConfigurer(EmbeddedDatabaseConfigurers.customizeConfigurer(
+				EmbeddedDatabaseType.H2, defaultConfigurer ->
+						new EmbeddedDatabaseConfigurerDelegate(defaultConfigurer) {
+							@Override
+							public void configureConnectionProperties(ConnectionProperties properties, String databaseName) {
+								super.configureConnectionProperties(properties, "custom-db-name");
+							}
+						}));
+		EmbeddedDatabase db = this.factory.getDatabase();
+		try (Connection connection = db.getConnection()) {
+			assertThat(connection.getMetaData().getURL()).contains("custom-db-name")
+					.doesNotContain("original-db-mame");
+		}
+		db.shutdown();
+	}
+
+	@Test
+	void customizeConfigurerWithCustomizedUrl() throws SQLException {
+		this.factory.setDatabaseName("original-db-mame");
+		this.factory.setDatabaseConfigurer(EmbeddedDatabaseConfigurers.customizeConfigurer(
+				EmbeddedDatabaseType.H2, defaultConfigurer ->
+						new EmbeddedDatabaseConfigurerDelegate(defaultConfigurer) {
+							@Override
+							public void configureConnectionProperties(ConnectionProperties properties, String databaseName) {
+								super.configureConnectionProperties(properties, databaseName);
+								properties.setUrl("jdbc:h2:mem:custom-db-name;DB_CLOSE_DELAY=-1;DB_CLOSE_ON_EXIT=false;MODE=MariaDB");
+							}
+						}));
+		EmbeddedDatabase db = this.factory.getDatabase();
+		try (Connection connection = db.getConnection()) {
+			assertThat(connection.getMetaData().getURL()).contains("custom-db-name")
+					.doesNotContain("original-db-mame");
+		}
+		db.shutdown();
+	}
+
 
 	private static class StubDatabasePopulator implements DatabasePopulator {