Liquibase should be able to execute with only spring-jdbc on the classpath

[xp-vit]

Spring Boot version: 2.3.0.M3

I have created a small project to test r2dbc work with spring boot:
https://github.com/xp-vit/r2dbc-liquibase/

When I try to start it I get:

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'liquibase' defined in class path resource [org/springframework/boot/autoconfigure/liquibase/LiquibaseAutoConfiguration$LiquibaseConfiguration.class]: Unsatisfied dependency expressed through method 'liquibase' parameter 0; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'spring.datasource-org.springframework.boot.autoconfigure.jdbc.DataSourceProperties': Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.boot.autoconfigure.jdbc.DataSourceProperties]: Constructor threw exception; nested exception is java.lang.NoClassDefFoundError: org/springframework/jdbc/datasource/embedded/EmbeddedDatabaseType
	at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:798) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:539) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1338) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1177) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:557) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:323) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:321) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:879) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:878) ~[spring-context-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:550) ~[spring-context-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.boot.web.reactive.context.ReactiveWebServerApplicationContext.refresh(ReactiveWebServerApplicationContext.java:66) ~[spring-boot-2.3.0.M3.jar:2.3.0.M3]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:758) ~[spring-boot-2.3.0.M3.jar:2.3.0.M3]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:750) ~[spring-boot-2.3.0.M3.jar:2.3.0.M3]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) ~[spring-boot-2.3.0.M3.jar:2.3.0.M3]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:315) ~[spring-boot-2.3.0.M3.jar:2.3.0.M3]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1237) ~[spring-boot-2.3.0.M3.jar:2.3.0.M3]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1226) ~[spring-boot-2.3.0.M3.jar:2.3.0.M3]
	at com.example.r2dbcliquibase.R2dbcLiquibaseApplication.main(R2dbcLiquibaseApplication.java:10) ~[main/:na]
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'spring.datasource-org.springframework.boot.autoconfigure.jdbc.DataSourceProperties': Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.boot.autoconfigure.jdbc.DataSourceProperties]: Constructor threw exception; nested exception is java.lang.NoClassDefFoundError: org/springframework/jdbc/datasource/embedded/EmbeddedDatabaseType
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1320) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1214) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:557) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:323) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:321) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:276) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1287) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1207) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:885) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:789) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	... 20 common frames omitted
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.boot.autoconfigure.jdbc.DataSourceProperties]: Constructor threw exception; nested exception is java.lang.NoClassDefFoundError: org/springframework/jdbc/datasource/embedded/EmbeddedDatabaseType
	at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:216) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:87) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1312) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	... 32 common frames omitted
Caused by: java.lang.NoClassDefFoundError: org/springframework/jdbc/datasource/embedded/EmbeddedDatabaseType
	at org.springframework.boot.jdbc.EmbeddedDatabaseConnection.<clinit>(EmbeddedDatabaseConnection.java:51) ~[spring-boot-2.3.0.M3.jar:2.3.0.M3]
	at org.springframework.boot.autoconfigure.jdbc.DataSourceProperties.<init>(DataSourceProperties.java:153) ~[spring-boot-autoconfigure-2.3.0.M3.jar:2.3.0.M3]
	at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:na]
	at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:na]
	at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:na]
	at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:490) ~[na:na]
	at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:203) ~[spring-beans-5.2.4.RELEASE.jar:5.2.4.RELEASE]
	... 34 common frames omitted
Caused by: java.lang.ClassNotFoundException: org.springframework.jdbc.datasource.embedded.EmbeddedDatabaseType
	at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:581) ~[na:na]
	at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178) ~[na:na]
	at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521) ~[na:na]
	... 41 common frames omitted

I understand that this can be theoretically solved with "spring-boot-starter-data-jdbc", but I was hoping to avoid it, because it brings unnecessary code + forces me to configure DataSource of exclude it from autoconfiguration.

[snicoll]

Thanks for the report.

There are two problems here. One we reuse DataSourceProperties to create the DataSource with the same defaults as the one we apply for the auto-config (detecting driver url and such). That requires spring-jdbc on the classpath. The other problem is that DataSourceProperties is going to lookup a DataSource implementation for us and it doesn't fallback on SimpleDriverDataSource so even adding spring-jdbc only does not work.

We can fix the latter but that would still require you to add spring-jdbc on the classpath which I think is fair enough considering the use case at hand. We'd need to update the documentation as well to make that more obvious.

It should be noted that when R2DBC is configured, the auto-configuration bits for the DataSource backs off so you shouldn't have to exclude it or be forced to create your own DataSource.