Make Flyway and Liquibase auto-config back off without spring-jdbc

The auto-config requires Spring JDBC for DataSource creation from
spring.flyway.url or spring.liquibase.url, checking Flyway migrations
exist, etc. Without it, the application fails to start due to missing
spring-jdbc classes.

This commit updates the auto-config so that it backs off in the
absence of spring-jdbc.

Closes gh-26849

Author: wilkinsona

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/flyway/FlywayAutoConfiguration.java

@@ -115,6 +115,7 @@ public FlywaySchemaManagementProvider flywayDefaultDdlModeProvider(ObjectProvide
 	}
 
 	@Configuration(proxyBeanMethods = false)
+	@ConditionalOnClass(JdbcUtils.class)
 	@ConditionalOnMissingBean(Flyway.class)
 	@EnableConfigurationProperties({ DataSourceProperties.class, FlywayProperties.class })
 	@Import({ FlywayMigrationInitializerEntityManagerFactoryDependsOnPostProcessor.class,

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/liquibase/LiquibaseAutoConfiguration.java

@@ -52,6 +52,7 @@
 import org.springframework.context.annotation.Conditional;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.Import;
+import org.springframework.jdbc.core.ConnectionCallback;
 import org.springframework.jdbc.core.JdbcOperations;
 import org.springframework.jdbc.core.namedparam.NamedParameterJdbcOperations;
 import org.springframework.jdbc.datasource.SimpleDriverDataSource;
@@ -92,6 +93,7 @@ public LiquibaseSchemaManagementProvider liquibaseDefaultDdlModeProvider(
 	}
 
 	@Configuration(proxyBeanMethods = false)
+	@ConditionalOnClass(ConnectionCallback.class)
 	@ConditionalOnMissingBean(SpringLiquibase.class)
 	@EnableConfigurationProperties({ DataSourceProperties.class, LiquibaseProperties.class })
 	public static class LiquibaseConfiguration {

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/flyway/FlywayAutoConfigurationTests.java

@@ -46,6 +46,7 @@
 import org.springframework.boot.jdbc.DataSourceBuilder;
 import org.springframework.boot.jdbc.SchemaManagement;
 import org.springframework.boot.orm.jpa.EntityManagerFactoryBuilder;
+import org.springframework.boot.test.context.FilteredClassLoader;
 import org.springframework.boot.test.context.runner.ApplicationContextRunner;
 import org.springframework.boot.test.system.CapturedOutput;
 import org.springframework.boot.test.system.OutputCaptureExtension;
@@ -104,6 +105,13 @@ void createsDataSourceWithNoDataSourceBeanAndFlywayUrl() {
 				});
 	}
 
+	@Test
+	void backsOffWithFlywayUrlAndNoSpringJdbc() {
+		this.contextRunner.withPropertyValues("spring.flyway.url:jdbc:hsqldb:mem:" + UUID.randomUUID())
+				.withClassLoader(new FilteredClassLoader("org.springframework.jdbc"))
+				.run((context) -> assertThat(context).doesNotHaveBean(Flyway.class));
+	}
+
 	@Test
 	void createDataSourceWithUrl() {
 		this.contextRunner.withUserConfiguration(EmbeddedDataSourceConfiguration.class)

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/liquibase/LiquibaseAutoConfigurationTests.java

@@ -21,6 +21,7 @@
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.Map;
+import java.util.UUID;
 import java.util.function.Consumer;
 
 import javax.sql.DataSource;
@@ -104,6 +105,13 @@ void createsDataSourceWithNoDataSourceBeanAndLiquibaseUrl() {
 				}));
 	}
 
+	@Test
+	void backsOffWithLiquibaseUrlAndNoSpringJdbc() {
+		this.contextRunner.withPropertyValues("spring.liquibase.url:jdbc:hsqldb:mem:" + UUID.randomUUID())
+				.withClassLoader(new FilteredClassLoader("org.springframework.jdbc"))
+				.run((context) -> assertThat(context).doesNotHaveBean(SpringLiquibase.class));
+	}
+
 	@Test
 	void createsDataSourceWhenSpringJdbcOnlyAvailableWithNoDataSourceBeanAndLiquibaseUrl() {
 		this.contextRunner.withPropertyValues("spring.liquibase.url:jdbc:hsqldb:mem:liquibase")