Unlike DataSourceAutoConfiguration, DevToolsDataSourceAutoConfiguration assumes that javax.sql.DataSource will always be available

[xenoterracide]

Unlike DataSourceAutoConfiguration, DevToolsDataSourceAutoConfiguration assumes that javax.sql.DataSource will always be available

[philwebb]

We've not done much testing with JPMS unfortunately. It looks like DevToolsDataSourceAutoConfiguration always assumes that javax.sql.DataSource is available. We can add some extra guards but it looks like that might not be enough.

If I add requires java.sql; to the module-info class we get around the SQL error but hit:

org.springframework.cglib.core.CodeGenerationException: java.lang.reflect.InaccessibleObjectException-->Unable to make protected final java.lang.Class java.lang.ClassLoader.defineClass(java.lang.String,byte[],int,int,java.security.ProtectionDomain) throws java.lang.ClassFormatError accessible: module java.base does not "opens java.lang" to unnamed module @281e3708
	at org.springframework.cglib.core.ReflectUtils.defineClass(ReflectUtils.java:547) ~[spring-core-6.1.5.jar:6.1.5]
	at org.springframework.cglib.core.AbstractClassGenerator.generate(AbstractClassGenerator.java:371) ~[spring-core-6.1.5.jar:6.1.5]
	at org.springframework.cglib.proxy.Enhancer.generate(Enhancer.java:575) ~[spring-core-6.1.5.jar:6.1.5]
	at org.springframework.cglib.core.AbstractClassGenerator$ClassLoaderData.lambda$new$1(AbstractClassGenerator.java:107) ~[spring-core-6.1.5.jar:6.1.5]
	at org.springframework.cglib.core.internal.LoadingCache.lambda$createEntry$1(LoadingCache.java:52) ~[spring-core-6.1.5.jar:6.1.5]
	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264) ~[na:na]
	at org.springframework.cglib.core.internal.LoadingCache.createEntry(LoadingCache.java:57) ~[spring-core-6.1.5.jar:6.1.5]
	at org.springframework.cglib.core.internal.LoadingCache.get(LoadingCache.java:34) ~[spring-core-6.1.5.jar:6.1.5]
	at org.springframework.cglib.core.AbstractClassGenerator$ClassLoaderData.get(AbstractClassGenerator.java:130) ~[spring-core-6.1.5.jar:6.1.5]
	at org.springframework.cglib.core.AbstractClassGenerator.create(AbstractClassGenerator.java:317) ~[spring-core-6.1.5.jar:6.1.5]
	at org.springframework.cglib.proxy.Enhancer.createHelper(Enhancer.java:562) ~[spring-core-6.1.5.jar:6.1.5]
	at org.springframework.cglib.proxy.Enhancer.createClass(Enhancer.java:407) ~[spring-core-6.1.5.jar:6.1.5]
	at org.springframework.context.annotation.ConfigurationClassEnhancer.createClass(ConfigurationClassEnhancer.java:138) ~[spring-context-6.1.5.jar:6.1.5]
	at org.springframework.context.annotation.ConfigurationClassEnhancer.enhance(ConfigurationClassEnhancer.java:109) ~[spring-context-6.1.5.jar:6.1.5]
	at org.springframework.context.annotation.ConfigurationClassPostProcessor.enhanceConfigurationClasses(ConfigurationClassPostProcessor.java:533) ~[spring-context-6.1.5.jar:6.1.5]
	at org.springframework.context.annotation.ConfigurationClassPostProcessor.postProcessBeanFactory(ConfigurationClassPostProcessor.java:310) ~[spring-context-6.1.5.jar:6.1.5]
	at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:363) ~[spring-context-6.1.5.jar:6.1.5]
	at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:153) ~[spring-context-6.1.5.jar:6.1.5]
	at org.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationContext.java:788) ~[spring-context-6.1.5.jar:6.1.5]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:606) ~[spring-context-6.1.5.jar:6.1.5]
	at [email protected]/org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:146) ~[spring-boot-3.2.4.jar:na]
	at [email protected]/org.springframework.boot.SpringApplication.refresh(SpringApplication.java:754) ~[spring-boot-3.2.4.jar:na]
	at [email protected]/org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:456) ~[spring-boot-3.2.4.jar:na]
	at [email protected]/org.springframework.boot.SpringApplication.run(SpringApplication.java:334) ~[spring-boot-3.2.4.jar:na]
	at [email protected]/org.springframework.boot.SpringApplication.run(SpringApplication.java:1354) ~[spring-boot-3.2.4.jar:na]
	at [email protected]/org.springframework.boot.SpringApplication.run(SpringApplication.java:1343) ~[spring-boot-3.2.4.jar:na]
	at bug.spring.security.jpms.main/org.example.bugspringsecurityjpms.BugSpringSecurityJpmsApplication.main(BugSpringSecurityJpmsApplication.java:10) ~[main/:na]
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77) ~[na:na]
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
	at java.base/java.lang.reflect.Method.invoke(Method.java:568) ~[na:na]
	at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:50) ~[spring-boot-devtools-3.2.4.jar:3.2.4]
Caused by: java.lang.reflect.InaccessibleObjectException: Unable to make protected final java.lang.Class java.lang.ClassLoader.defineClass(java.lang.String,byte[],int,int,java.security.ProtectionDomain) throws java.lang.ClassFormatError accessible: module java.base does not "opens java.lang" to unnamed module @281e3708
	at java.base/java.lang.reflect.AccessibleObject.checkCanSetAccessible(AccessibleObject.java:354) ~[na:na]
	at java.base/java.lang.reflect.AccessibleObject.checkCanSetAccessible(AccessibleObject.java:297) ~[na:na]
	at java.base/java.lang.reflect.Method.checkCanSetAccessible(Method.java:199) ~[na:na]
	at java.base/java.lang.reflect.Method.setAccessible(Method.java:193) ~[na:na]
	at org.springframework.cglib.core.ReflectUtils.defineClass(ReflectUtils.java:505) ~[spring-core-6.1.5.jar:6.1.5]
	... 31 common frames omitted

[philwebb]

I don't think we need another bug, but I suspect we'll need to fix both before we can get devtools to work with JPMS.

[xenoterracide]

I suspect spring-projects/spring-framework#32671 (already mentioned) getting fixed would resolve this other issue? or does spring framework need yet another bug?

[xenoterracide]

I'm not 100% on this because my module-info set up is weird for testing with this feature variant... but since you're looking into things I'll leave this comment on actuator. I'll try creating a bug/repro in the next week. Saw this after changing spring-projects/spring-framework#32671 (comment)

 Caused by: java.lang.NoClassDefFoundError: com/fasterxml/jackson/databind/Module
	at org.springframework.boot.actuate.autoconfigure.context.properties.ConfigurationPropertiesReportEndpointAutoConfiguration.configurationPropertiesReportEndpoint(ConfigurationPropertiesReportEndpointAutoConfiguration.java:51)

[wilkinsona]

Given that we don't test Devtools, or any of Boot, with JPMS as it isn't a priority, I think we should focus this on the faulty assumption that javax.sql.DataSource will always be available. DataSourceAutoConfiguration does not make that assumption so DevToolsDataSourceAutoConfiguration should not do so either. It may be enough on the Spring Boot side to get Devtools working with JPMS, but I'm not sure we should be claiming support for it unless we're prepared to test it.

[jhoeller]

A follow-up to the Spring Framework comments above: There is no obvious "fix" for spring-projects/spring-framework#32671 - it's a fundamental platform limitation rather than some kind of CGLIB legacy that we could do something about. If there is anything concrete that we can improve for SmartClassLoader.publicDefineClass to empower the Boot RestartClassLoader, please let us know. Otherwise, we could only really add a stronger documentation note on these limitations.