JPA „cannot be resolved to URL because it does not exist" in Spring-Boot 1.4

[masrawi]

I have the same issue with the current 1.4.0.BUILD-SNAPSHOT as with #5842 . it has to do with having the starter application class not in the root package. with 1.3.5 it works without any additional @EntityScan but with the latest build it fails.

spring-boot-example-5842.zip

[jhoeller]

@wilkinsona Could this have anything to do with the changes behind SPR-14246? If any refinements are needed there, let's sort this out ASAP since we're aiming to release 4.3.1 later today...

[snicoll]

@masrawi you are reporting an issue and the sample doesn't match. I already replied to #5842 so if you want us to look into this, please attach a sample that actually reproduces the issue you're experiencing. Maybe you forgot to add orm.xml to your sample?

[masrawi]

@snicoll I already replied to your comment there. the only difference to the sample here is that @componentscan({ „base“ }) is not there as it is redundant. I do not use orm.xml in any of the examples

[wilkinsona]

This isn't the same as #5842 as there's no orm.xml in the application and scanning is being performed. However, the failure is the same:

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaAutoConfiguration.class]: Invocation of init method failed; nested exception is javax.persistence.PersistenceException: Unable to resolve persistence unit root URL
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1578) ~[spring-beans-4.3.1.BUILD-SNAPSHOT.jar!/:4.3.1.BUILD-SNAPSHOT]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:545) ~[spring-beans-4.3.1.BUILD-SNAPSHOT.jar!/:4.3.1.BUILD-SNAPSHOT]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482) ~[spring-beans-4.3.1.BUILD-SNAPSHOT.jar!/:4.3.1.BUILD-SNAPSHOT]
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) ~[spring-beans-4.3.1.BUILD-SNAPSHOT.jar!/:4.3.1.BUILD-SNAPSHOT]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) ~[spring-beans-4.3.1.BUILD-SNAPSHOT.jar!/:4.3.1.BUILD-SNAPSHOT]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) ~[spring-beans-4.3.1.BUILD-SNAPSHOT.jar!/:4.3.1.BUILD-SNAPSHOT]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) ~[spring-beans-4.3.1.BUILD-SNAPSHOT.jar!/:4.3.1.BUILD-SNAPSHOT]
    at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1076) ~[spring-context-4.3.1.BUILD-SNAPSHOT.jar!/:4.3.1.BUILD-SNAPSHOT]
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:851) ~[spring-context-4.3.1.BUILD-SNAPSHOT.jar!/:4.3.1.BUILD-SNAPSHOT]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:541) ~[spring-context-4.3.1.BUILD-SNAPSHOT.jar!/:4.3.1.BUILD-SNAPSHOT]
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122) ~[spring-boot-1.4.0.BUILD-SNAPSHOT.jar!/:1.4.0.BUILD-SNAPSHOT]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:759) [spring-boot-1.4.0.BUILD-SNAPSHOT.jar!/:1.4.0.BUILD-SNAPSHOT]
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:369) [spring-boot-1.4.0.BUILD-SNAPSHOT.jar!/:1.4.0.BUILD-SNAPSHOT]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:313) [spring-boot-1.4.0.BUILD-SNAPSHOT.jar!/:1.4.0.BUILD-SNAPSHOT]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1185) [spring-boot-1.4.0.BUILD-SNAPSHOT.jar!/:1.4.0.BUILD-SNAPSHOT]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1174) [spring-boot-1.4.0.BUILD-SNAPSHOT.jar!/:1.4.0.BUILD-SNAPSHOT]
    at bootstrap.Application.main(Application.java:14) [classes!/:0.0.1-SNAPSHOT]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_74]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_74]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_74]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_74]
    at org.springframework.boot.loader.MainMethodRunner.run(MainMethodRunner.java:48) [spring-boot-example-0.0.1-SNAPSHOT.jar:0.0.1-SNAPSHOT]
    at org.springframework.boot.loader.Launcher.launch(Launcher.java:87) [spring-boot-example-0.0.1-SNAPSHOT.jar:0.0.1-SNAPSHOT]
    at org.springframework.boot.loader.Launcher.launch(Launcher.java:50) [spring-boot-example-0.0.1-SNAPSHOT.jar:0.0.1-SNAPSHOT]
    at org.springframework.boot.loader.JarLauncher.main(JarLauncher.java:58) [spring-boot-example-0.0.1-SNAPSHOT.jar:0.0.1-SNAPSHOT]
Caused by: javax.persistence.PersistenceException: Unable to resolve persistence unit root URL
    at org.springframework.orm.jpa.persistenceunit.DefaultPersistenceUnitManager.determineDefaultPersistenceUnitRootUrl(DefaultPersistenceUnitManager.java:603) ~[spring-orm-4.3.1.BUILD-SNAPSHOT.jar!/:4.3.1.BUILD-SNAPSHOT]
    at org.springframework.orm.jpa.persistenceunit.DefaultPersistenceUnitManager.preparePersistenceUnitInfos(DefaultPersistenceUnitManager.java:443) ~[spring-orm-4.3.1.BUILD-SNAPSHOT.jar!/:4.3.1.BUILD-SNAPSHOT]
    at org.springframework.orm.jpa.persistenceunit.DefaultPersistenceUnitManager.afterPropertiesSet(DefaultPersistenceUnitManager.java:424) ~[spring-orm-4.3.1.BUILD-SNAPSHOT.jar!/:4.3.1.BUILD-SNAPSHOT]
    at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:310) ~[spring-orm-4.3.1.BUILD-SNAPSHOT.jar!/:4.3.1.BUILD-SNAPSHOT]
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:373) ~[spring-orm-4.3.1.BUILD-SNAPSHOT.jar!/:4.3.1.BUILD-SNAPSHOT]
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:362) ~[spring-orm-4.3.1.BUILD-SNAPSHOT.jar!/:4.3.1.BUILD-SNAPSHOT]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1637) ~[spring-beans-4.3.1.BUILD-SNAPSHOT.jar!/:4.3.1.BUILD-SNAPSHOT]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1574) ~[spring-beans-4.3.1.BUILD-SNAPSHOT.jar!/:4.3.1.BUILD-SNAPSHOT]
    ... 24 common frames omitted
Caused by: java.io.FileNotFoundException: class path resource [] cannot be resolved to URL because it does not exist
    at org.springframework.core.io.ClassPathResource.getURL(ClassPathResource.java:187) ~[spring-core-4.3.1.BUILD-SNAPSHOT.jar!/:4.3.1.BUILD-SNAPSHOT]
    at org.springframework.orm.jpa.persistenceunit.DefaultPersistenceUnitManager.determineDefaultPersistenceUnitRootUrl(DefaultPersistenceUnitManager.java:600) ~[spring-orm-4.3.1.BUILD-SNAPSHOT.jar!/:4.3.1.BUILD-SNAPSHOT]
    ... 31 common frames omitted

I need to dig into it some more to figure out exactly where the problem lies, but I don't think it's directly related to SPR-14246 which handled a case where there was an orm.xml and scanning wasn't being performed.

[snicoll]

@masrawi it would help if you could be a bit more precise when reporting an issue. For one you added a comment in a very focused issue that's actually not your issue at all (only the exception is). Then, you project is broken in 1.3 and 1.4 for me. If you start that project in the IDE, your persistence unit is empty (there's no DDL generation even though you enforce SQL generation in your custom configuration). All that noise in the sample really doesn't help.

So I tried your sample in 1.3 running the fat jar. Yes it does start but the persistence unit is empty and you can't really use the JPA infrastructure. Is that sample representative of a real world use case?

[wilkinsona]

I think I now understand what's happening and why. It "fails" silently with 1.3.5 as the app starts but leaves you with an empty persistence unit, whereas 1.4 catches the misconfigured entity scanning and fails early on. If the sample tried to make use of the entities, 1.3.5 would also fail, albeit later on.

The sample is a little unusual as it has no orm.xml, its entity isn't in the same package as the main application class, and @EntityScan isn't used. This means that, as far as Spring ORM/Hibernate are concerned, there aren't any entities. As mentioned above, it only works at all as the entity isn't actually used in the sample.

When using 1.3.5 and a Spring Boot fat jar, the ill-advised fix #420 means that startup doesn't fail but the persistence unit is empty. When using 1.3.5 and a shaded jar the application fails to start due to the mis-configured entity scanning. That it to say, the behaviour of a shaded jar is arguably better than the behaviour of a fat jar as it catches the misconfiguration earlier.

When using 1.4, the app fails to start due to the misconfigured entity scanning. This is the same for both a fat jar and a shaded jar. There's no orm.xml in the application so the fix for SPR-14246 doesn't come into play.