Esta dando erro no console, podem me ajudar, segue abaixo.

Oi Marsia,

Pode postar aqui o log completo que saiu no console?

06:11:23.333 [Thread-0] DEBUG org.springframework.boot.devtools.restart.classloader.RestartClassLoader - Created RestartClassLoader org.springframework.boot.devtools.restart.classloader.RestartClassLoader@3986c00b

. __ _ __ _ _ /\ / _'_ _ _ _()_ _ __ _ \ \ \ ( ( )___ | ' | '| | ' / ` | \ \ \ \/ ___)| |)| | | | | || (| | ) ) ) ) ' |__| .|| ||_| |_, | / / / / =========||==============|__/=//// :: Spring Boot :: (v2.6.5)

2022-04-28 06:11:24.166 INFO 5408 --- [ restartedMain] br.com.alura.forum.ForumApplication : Starting ForumApplication using Java 17.0.2 on DESKTOP-7H2ETIR with PID 5408 (C:\Users\Dell\Documents\Spring Boot\forum\target\classes started by Dell in C:\Users\Dell\Documents\Spring Boot\forum) 2022-04-28 06:11:24.168 INFO 5408 --- [ restartedMain] br.com.alura.forum.ForumApplication : No active profile set, falling back to 1 default profile: "default" 2022-04-28 06:11:24.332 INFO 5408 --- [ restartedMain] .e.DevToolsPropertyDefaultsPostProcessor : Devtools property defaults active! Set 'spring.devtools.add-properties' to 'false' to disable 2022-04-28 06:11:24.333 INFO 5408 --- [ restartedMain] .e.DevToolsPropertyDefaultsPostProcessor : For additional web related logging consider setting the 'logging.level.web' property to 'DEBUG' 2022-04-28 06:11:25.775 INFO 5408 --- [ restartedMain] .s.d.r.c.RepositoryConfigurationDelegate : Bootstrapping Spring Data JPA repositories in DEFAULT mode. 2022-04-28 06:11:25.808 INFO 5408 --- [ restartedMain] .s.d.r.c.RepositoryConfigurationDelegate : Finished Spring Data repository scanning in 11 ms. Found 0 JPA repository interfaces. 2022-04-28 06:11:27.436 INFO 5408 --- [ restartedMain] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 8080 (http) 2022-04-28 06:11:27.461 INFO 5408 --- [ restartedMain] o.apache.catalina.core.StandardService : Starting service [Tomcat] 2022-04-28 06:11:27.461 INFO 5408 --- [ restartedMain] org.apache.catalina.core.StandardEngine : Starting Servlet engine: [Apache Tomcat/9.0.60] 2022-04-28 06:11:27.665 INFO 5408 --- [ restartedMain] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext 2022-04-28 06:11:27.665 INFO 5408 --- [ restartedMain] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 3331 ms 2022-04-28 06:11:27.775 INFO 5408 --- [ restartedMain] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Starting... 2022-04-28 06:11:28.117 INFO 5408 --- [ restartedMain] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Start completed. 2022-04-28 06:11:28.141 INFO 5408 --- [ restartedMain] o.s.b.a.h2.H2ConsoleAutoConfiguration : H2 console available at '/h2-console'. Database available at 'jdbc:h2:mem:alura-forum' 2022-04-28 06:11:28.524 INFO 5408 --- [ restartedMain] o.hibernate.jpa.internal.util.LogHelper : HHH000204: Processing PersistenceUnitInfo [name: default] 2022-04-28 06:11:28.695 INFO 5408 --- [ restartedMain] org.hibernate.Version : HHH000412: Hibernate ORM core version 5.6.7.Final 2022-04-28 06:11:29.075 INFO 5408 --- [ restartedMain] o.hibernate.annotations.common.Version : HCANN000001: Hibernate Commons Annotations {5.1.2.Final} 2022-04-28 06:11:29.384 INFO 5408 --- [ restartedMain] org.hibernate.dialect.Dialect : HHH000400: Using dialect: org.hibernate.dialect.H2Dialect 2022-04-28 06:11:29.704 ERROR 5408 --- [ restartedMain] j.LocalContainerEntityManagerFactoryBean : Failed to initialize JPA EntityManagerFactory: No i

identifier specified for entity: br.com.alura.forum.modelo.Resposta 2022-04-28 06:11:29.705 WARN 5408 --- [ restartedMain] ConfigServletWebServerApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaConfiguration.class]: Invocation of init method failed; nested exception is org.hibernate.AnnotationException: No identifier specified for entity: br.com.alura.forum.modelo.Resposta 2022-04-28 06:11:29.944 WARN 5408 --- [ restartedMain] o.s.b.f.support.DisposableBeanAdapter : Invocation of destroy method failed on bean with name 'inMemoryDatabaseShutdownExecutor': org.h2.jdbc.JdbcSQLNonTransientConnectionException: Database is already closed (to disable automatic closing at VM shutdown, add ";DB_CLOSE_ON_EXIT=FALSE" to the db URL) [90121-200] 2022-04-28 06:11:29.944 INFO 5408 --- [ restartedMain] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Shutdown initiated... 2022-04-28 06:11:29.951 INFO 5408 --- [ restartedMain] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Shutdown completed. 2022-04-28 06:11:29.956 INFO 5408 --- [ restartedMain] o.apache.catalina.core.StandardService : Stopping service [Tomcat] 2022-04-28 06:11:29.985 INFO 5408 --- [ restartedMain] ConditionEvaluationReportLoggingListener :

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled. 2022-04-28 06:11:30.050 ERROR 5408 --- [ restartedMain] o.s.boot.SpringApplication : Application run failed

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaConfiguration.class]: Invocation of init method failed; nested exception is org.hibernate.AnnotationException: No identifier specified for entity: br.com.alura.forum.modelo.Resposta at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1804) ~[spring-beans-5.3.17.jar:5.3.17] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:620) ~[spring-beans-5.3.17.jar:5.3.17] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:542) ~[spring-beans-5.3.17.jar:5.3.17] at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.17.jar:5.3.17] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.17.jar:5.3.17] at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.17.jar:5.3.17] at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.17.jar:5.3.17]

at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.17.jar:5.3.17]
at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1154) ~[spring-context-5.3.17.jar:5.3.17]
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:908) ~[spring-context-5.3.17.jar:5.3.17]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:583) ~[spring-context-5.3.17.jar:5.3.17]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145) ~[spring-boot-2.6.5.jar:2.6.5]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:740) ~[spring-boot-2.6.5.jar:2.6.5]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:415) ~[spring-boot-2.6.5.jar:2.6.5]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:303) ~[spring-boot-2.6.5.jar:2.6.5]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1312) ~[spring-boot-2.6.5.jar:2.6.5]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1301) ~[spring-boot-2.6.5.jar:2.6.5]
at br.com.alura.forum.ForumApplication.main(ForumApplication.java:10) ~[classes/: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:49) ~[spring-boot-devtools-2.6.5.jar:2.6.5]

Caused by: org.hibernate.AnnotationException: No identifier specified for entity: br.com.alura.forum.modelo.Resposta at org.hibernate.cfg.InheritanceState.determineDefaultAccessType(InheritanceState.java:266) ~[hibernate-core-5.6.7.Final.jar:5.6.7.Final] at org.hibernate.cfg.InheritanceState.getElementsToProcess(InheritanceState.java:211) ~[hibernate-core-5.6.7.Final.jar:5.6.7.Final] at org.hibernate.cfg.AnnotationBinder.bindClass(AnnotationBinder.java:772) ~[hibernate-core-5.6.7.Final.jar:5.6.7.Final] at org.hibernate.boot.model.source.internal.annotations.AnnotationMetadataSourceProcessorImpl.processEntityHierarchies(AnnotationMetadataSourceProcessorImpl.java:225) ~[hibernate-core-5.6.7.Final.jar:5.6.7.Final] at org.hibernate.boot.model.process.spi.MetadataBuildingProcess$1.processEntityHierarchies(MetadataBuildingProcess.java:239) ~[hibernate-core-5.6.7.Final.jar:5.6.7.Final] at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:282) ~[hibernate-core-5.6.7.Final.jar:5.6.7.Final] at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.metadata(EntityManagerFactoryBuilderImpl.java:1460) ~[hibernate-core-5.6.7.Final.jar:5.6.7.Final] at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:1494) ~[hibernate-core-5.6.7.Final.jar:5.6.7.Final] at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:58) ~[spring-orm-5.3.17.jar:5.3.17] at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:365) ~[spring-orm-5.3.17.jar:5.3.17] at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:409) ~[spring-orm-5.3.17.jar:5.3.17] at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:396) ~[spring-orm-5.3.17.jar:5.3.17] at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.afterPropertiesSet(LocalContainerEntityManagerFactoryBean.java:341) ~[spring-orm-5.3.17.jar:5.3.17] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1863) ~[spring-beans-5.3.17.jar:5.3.17] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1800) ~[spring-beans-5.3.17.jar:5.3.17] ... 21 common frames omitted

O erro: Caused by: org.hibernate.AnnotationException: No identifier specified for entity: br.com.alura.forum.modelo.Resposta

Sua entidade Resposta deve estar sem a anotação @Id em cima do atributo id.

Obrigada Rodrigo pela atenção, fiz a correção e está compilando perfeitamente.