Application context fails in when thymeleaf template directory exists but is empty

[adambro]

Steps:

• create new Eclipse project from Thymeleaf starter
• change version in POM to 1.0.0.RC4
• run: mvn test
• see: failed to load ApplicationContext due to Thymeleaf template directory not being found (see below for stack trace)

It does not happen when dependency is switched to 1.0.0.RC3 (so regression) neither when using spring-boot-starter-web as dependency.

2014-03-04 12:38:43.902  INFO 28339 --- [           main] o.a.maven.surefire.booter.ForkedBooter   : Starting ForkedBooter v2.15 on ThinkTank with PID 28339 (/home/adam/.m2/repository/org/apache/maven/surefire/surefire-booter/2.15/surefire-booter-2.15.jar started by adam)
2014-03-04 12:38:43.939  INFO 28339 --- [           main] s.c.a.AnnotationConfigApplicationContext : Refreshing org.springframework.context.annotation.AnnotationConfigApplicationContext@20a9562f: startup date [Tue Mar 04 12:38:43 CET 2014]; root of context hierarchy
2014-03-04 12:38:44.551  INFO 28339 --- [           main] .b.l.ClasspathLoggingApplicationListener : Application failed to start with classpath: [file:/home/adam/var/eclipse/spring/softwaremill_task_adambro/target/surefire/surefirebooter5287899975510804302.jar]
2014-03-04 12:38:44.551  INFO 28339 --- [           main] utoConfigurationReportLoggingInitializer : 

Error starting ApplicationContext. To display the auto-configuration report enabled debug logging (start with --debug)


2014-03-04 12:38:44.558 ERROR 28339 --- [           main] o.s.test.context.TestContextManager      : Caught exception while allowing TestExecutionListener [org.springframework.test.context.support.DependencyInjectionTestExecutionListener@5bdd31be] to prepare test instance [softwaremill_task_adambro.ApplicationTests@6033cf4d]

java.lang.IllegalStateException: Failed to load ApplicationContext
    at org.springframework.test.context.CacheAwareContextLoaderDelegate.loadContext(CacheAwareContextLoaderDelegate.java:99)
    at org.springframework.test.context.DefaultTestContext.getApplicationContext(DefaultTestContext.java:101)
    at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.injectDependencies(DependencyInjectionTestExecutionListener.java:109)
    at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.prepareTestInstance(DependencyInjectionTestExecutionListener.java:75)
    at org.springframework.test.context.TestContextManager.prepareTestInstance(TestContextManager.java:319)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.createTest(SpringJUnit4ClassRunner.java:212)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner$1.runReflectiveCall(SpringJUnit4ClassRunner.java:289)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.methodBlock(SpringJUnit4ClassRunner.java:291)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:232)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:89)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
    at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
    at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:71)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:175)
    at org.apache.maven.surefire.junit4.JUnit4Provider.execute(JUnit4Provider.java:264)
    at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:153)
    at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:124)
    at org.apache.maven.surefire.booter.ForkedBooter.invokeProviderInSameClassLoader(ForkedBooter.java:200)
    at org.apache.maven.surefire.booter.ForkedBooter.runSuitesInProcess(ForkedBooter.java:153)
    at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:103)
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.boot.autoconfigure.thymeleaf.ThymeleafAutoConfiguration$ThymeleafViewResolverConfiguration': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private org.thymeleaf.spring4.SpringTemplateEngine org.springframework.boot.autoconfigure.thymeleaf.ThymeleafAutoConfiguration$ThymeleafViewResolverConfiguration.templateEngine; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.boot.autoconfigure.thymeleaf.ThymeleafAutoConfiguration$ThymeleafDefaultConfiguration': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private final java.util.Collection org.springframework.boot.autoconfigure.thymeleaf.ThymeleafAutoConfiguration$ThymeleafDefaultConfiguration.templateResolvers; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.boot.autoconfigure.thymeleaf.ThymeleafAutoConfiguration$DefaultTemplateResolverConfiguration': Invocation of init method failed; nested exception is java.lang.IllegalStateException: Cannot find template location: class path resource [templates/] (are you really using Thymeleaf?)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:292)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1185)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:537)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:475)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:304)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:300)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:195)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:700)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:760)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:482)
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:619)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:306)
    at org.springframework.boot.test.SpringApplicationContextLoader.loadContext(SpringApplicationContextLoader.java:79)
    at org.springframework.test.context.CacheAwareContextLoaderDelegate.loadContextInternal(CacheAwareContextLoaderDelegate.java:64)
    at org.springframework.test.context.CacheAwareContextLoaderDelegate.loadContext(CacheAwareContextLoaderDelegate.java:91)
    ... 25 common frames omitted

[dsyer]

That was intentional (per #294). If you try to use Thymeleaf but don't have any templates isn't it kinder to fail on startup rather than pretend that the app is going to work later?

[adambro]

Failing at startup is fine, as long as it gives a hint what is wrong. The problem is I've tried to create templates dir, but it kept failing. It made me awry, thinking that my classpath is messed up. Steps as above plus:

mkdir -p src/main/resources/templates
mvn clean test

Wouldn't it be nicer to add some dummy template to starter? It would hint where those templates should be placed for beginners IMHO.

[dsyer]

Dummy templates in the starter would mess up the user's app I think (2 templates/ directories in the classpath). Nice idea though. Is the exception not explicit enough for beginners ("Cannot find templates at ..." seems pretty clear to me)? Any other suggestions?

BTW I just found out that the GS guides do not have Thymeleaf templates in classpath:/templates and yet they still worked with RC3. So this exception needs to be tweaked anyway.

[adambro]

The message says: Cannot find template location: class path resource [templates/] (are you really using Thymeleaf?) which is misleading, because I've created this location (mkdir), but it was empty. After copying some templates from other application it worked.

Spring Boot is opinionated and tries to follow convention over configuration if I read it right. IMHO it makes sense to provide templates for application starter that is about web templating language / extension. No hard feelings, I'm beginner here to Spring and Spring Boot.

[dsyer]

I see. It's not very good at detecting existing directories then. We'll have to fix that.

[dsyer]

The problem appears to be just that an empty directory is not copied to the class path by the IDE (or build tools probably). I changed the exception message to "Cannot find template location: classpath:/templates/ (please add some templates or check your Thymeleaf configuration)". Does that make it clear enough?

[adambro]

Clear enough - it points to the right direction. Thanks.