I would like to run my containerized Java Spring application which runs completely fine on my machine (of course, lol).
I have a problem with the JPA database connection.
What stumps me is that this also happens all the same when using just the H2 in-memory database.
Here is the error in the Docker container:

2024-12-02 13:37:39 java.lang.NullPointerException: Cannot invoke "org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(java.sql.SQLException, String)" because the return value of "org.hibernate.resource.transaction.backend.jdbc.internal.JdbcIsolationDelegate.sqlExceptionHelper()" is null
2024-12-02 13:37:39     at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcIsolationDelegate.delegateWork(JdbcIsolationDelegate.java:116) ~[hibernate-core-6.5.2.Final.jar!/:6.5.2.Final]
2024-12-02 13:37:39     at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.getJdbcEnvironmentUsingJdbcMetadata(JdbcEnvironmentInitiator.java:290) ~[hibernate-core-6.5.2.Final.jar!/:6.5.2.Final]
2024-12-02 13:37:39     at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:123) ~[hibernate-core-6.5.2.Final.jar!/:6.5.2.Final]
2024-12-02 13:37:39     at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:77) ~[hibernate-core-6.5.2.Final.jar!/:6.5.2.Final]
2024-12-02 13:37:39     at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.initiateService(StandardServiceRegistryImpl.java:130) ~[hibernate-core-6.5.2.Final.jar!/:6.5.2.Final]
2024-12-02 13:37:39     at org.hibernate.service.internal.AbstractServiceRegistryImpl.createService(AbstractServiceRegistryImpl.java:263) ~[hibernate-core-6.5.2.Final.jar!/:6.5.2.Final]
2024-12-02 13:37:39     at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:238) ~[hibernate-core-6.5.2.Final.jar!/:6.5.2.Final]
2024-12-02 13:37:39     at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:215) ~[hibernate-core-6.5.2.Final.jar!/:6.5.2.Final]
2024-12-02 13:37:39     at org.hibernate.boot.model.relational.Database.<init>(Database.java:45) ~[hibernate-core-6.5.2.Final.jar!/:6.5.2.Final]
2024-12-02 13:37:39     at org.hibernate.boot.internal.InFlightMetadataCollectorImpl.getDatabase(InFlightMetadataCollectorImpl.java:221) ~[hibernate-core-6.5.2.Final.jar!/:6.5.2.Final]
2024-12-02 13:37:39     at org.hibernate.boot.internal.InFlightMetadataCollectorImpl.<init>(InFlightMetadataCollectorImpl.java:189) ~[hibernate-core-6.5.2.Final.jar!/:6.5.2.Final]
2024-12-02 13:37:39     at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:171) ~[hibernate-core-6.5.2.Final.jar!/:6.5.2.Final]
2024-12-02 13:37:39     at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.metadata(EntityManagerFactoryBuilderImpl.java:1431) ~[hibernate-core-6.5.2.Final.jar!/:6.5.2.Final]
2024-12-02 13:37:39     at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:1502) ~[hibernate-core-6.5.2.Final.jar!/:6.5.2.Final]
2024-12-02 13:37:39     at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:75) ~[spring-orm-6.1.10.jar!/:6.1.10]
2024-12-02 13:37:39     at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:390) ~[spring-orm-6.1.10.jar!/:6.1.10]
2024-12-02 13:37:39     at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:409) ~[spring-orm-6.1.10.jar!/:6.1.10]
2024-12-02 13:37:39     at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:396) ~[spring-orm-6.1.10.jar!/:6.1.10]
2024-12-02 13:37:39     at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.afterPropertiesSet(LocalContainerEntityManagerFactoryBean.java:366) ~[spring-orm-6.1.10.jar!/:6.1.10]
2024-12-02 13:37:39     at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1835) ~[spring-beans-6.1.10.jar!/:6.1.10]
2024-12-02 13:37:39     at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1784) ~[spring-beans-6.1.10.jar!/:6.1.10]
2024-12-02 13:37:39     at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:600) ~[spring-beans-6.1.10.jar!/:6.1.10]
2024-12-02 13:37:39     at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:522) ~[spring-beans-6.1.10.jar!/:6.1.10]
2024-12-02 13:37:39     at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:337) ~[spring-beans-6.1.10.jar!/:6.1.10]
2024-12-02 13:37:39     at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-6.1.10.jar!/:6.1.10]
2024-12-02 13:37:39     at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:335) ~[spring-beans-6.1.10.jar!/:6.1.10]
2024-12-02 13:37:39     at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:205) ~[spring-beans-6.1.10.jar!/:6.1.10]
2024-12-02 13:37:39     at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:952) ~[spring-context-6.1.10.jar!/:6.1.10]
2024-12-02 13:37:39     at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:624) ~[spring-context-6.1.10.jar!/:6.1.10]
2024-12-02 13:37:39     at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:146) ~[spring-boot-3.3.1.jar!/:3.3.1]
2024-12-02 13:37:39     at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:754) ~[spring-boot-3.3.1.jar!/:3.3.1]
2024-12-02 13:37:39     at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:456) ~[spring-boot-3.3.1.jar!/:3.3.1]
2024-12-02 13:37:39     at org.springframework.boot.SpringApplication.run(SpringApplication.java:335) ~[spring-boot-3.3.1.jar!/:3.3.1]
2024-12-02 13:37:39     at org.springframework.boot.SpringApplication.run(SpringApplication.java:1363) ~[spring-boot-3.3.1.jar!/:3.3.1]
2024-12-02 13:37:39     at org.springframework.boot.SpringApplication.run(SpringApplication.java:1352) ~[spring-boot-3.3.1.jar!/:3.3.1]
2024-12-02 13:37:39     at com.rungroop.web.WebApplication.main(WebApplication.java:10) ~[!/:0.0.1-SNAPSHOT]
2024-12-02 13:37:39     at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
2024-12-02 13:37:39     at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77) ~[na:na]
2024-12-02 13:37:39     at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
2024-12-02 13:37:39     at java.base/java.lang.reflect.Method.invoke(Method.java:568) ~[na:na]
2024-12-02 13:37:39     at org.springframework.boot.loader.launch.Launcher.launch(Launcher.java:91) ~[app.jar:0.0.1-SNAPSHOT]
2024-12-02 13:37:39     at org.springframework.boot.loader.launch.Launcher.launch(Launcher.java:53) ~[app.jar:0.0.1-SNAPSHOT]
2024-12-02 13:37:39     at org.springframework.boot.loader.launch.JarLauncher.main(JarLauncher.java:58) ~[app.jar:0.0.1-SNAPSHOT]
2024-12-02 13:37:39 
2024-12-02 13:37:39 2024-12-02T12:37:39.141Z ERROR 1 --- [web] [           main] j.LocalContainerEntityManagerFactoryBean : Failed to initialize JPA EntityManagerFactory: Unable to create requested service [org.hibernate.engine.jdbc.env.spi.JdbcEnvironment] due to: Unable to determine Dialect without JDBC metadata (please set 'jakarta.persistence.jdbc.url' for common cases or 'hibernate.dialect' when a custom Dialect implementation must be provided)
2024-12-02 13:37:39 2024-12-02T12:37:39.142Z  WARN 1 --- [web] [           main] 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]: Unable to create requested service [org.hibernate.engine.jdbc.env.spi.JdbcEnvironment] due to: Unable to determine Dialect without JDBC metadata (please set 'jakarta.persistence.jdbc.url' for common cases or 'hibernate.dialect' when a custom Dialect implementation must be provided)
2024-12-02 13:37:39 2024-12-02T12:37:39.147Z  INFO 1 --- [web] [           main] o.apache.catalina.core.StandardService   : Stopping service [Tomcat]
2024-12-02 13:37:39 2024-12-02T12:37:39.163Z  INFO 1 --- [web] [           main] .s.b.a.l.ConditionEvaluationReportLogger : 
2024-12-02 13:37:39 
2024-12-02 13:37:39 Error starting ApplicationContext. To display the condition evaluation report re-run your application with 'debug' enabled.
2024-12-02 13:37:39 2024-12-02T12:37:39.179Z ERROR 1 --- [web] [           main] o.s.boot.SpringApplication               : Application run failed
2024-12-02 13:37:39 
2024-12-02 13:37:39 org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaConfiguration.class]: Unable to create requested service [org.hibernate.engine.jdbc.env.spi.JdbcEnvironment] due to: Unable to determine Dialect without JDBC metadata (please set 'jakarta.persistence.jdbc.url' for common cases or 'hibernate.dialect' when a custom Dialect implementation must be provided)
2024-12-02 13:37:39     at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1788) ~[spring-beans-6.1.10.jar!/:6.1.10]
2024-12-02 13:37:39     at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:600) ~[spring-beans-6.1.10.jar!/:6.1.10]
2024-12-02 13:37:39     at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:522) ~[spring-beans-6.1.10.jar!/:6.1.10]
2024-12-02 13:37:39     at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:337) ~[spring-beans-6.1.10.jar!/:6.1.10]
2024-12-02 13:37:39     at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-6.1.10.jar!/:6.1.10]
2024-12-02 13:37:39     at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:335) ~[spring-beans-6.1.10.jar!/:6.1.10]
2024-12-02 13:37:39     at ...
2024-12-02 13:37:39 Caused by: org.hibernate.HibernateException: Unable to determine Dialect without JDBC metadata (please set 'jakarta.persistence.jdbc.url' for common cases or 'hibernate.dialect' when a custom Dialect implementation must be provided)
2024-12-02 13:37:39     at org.hibernate.engine.jdbc.dialect.internal.DialectFactoryImpl.determineDialect(DialectFactoryImpl.java:191) ~[hibernate-core-6.5.2.Final.jar!/:6.5.2.Final]
2024-12-02 13:37:39     at org.hibernate.engine.jdbc.dialect.internal.DialectFactoryImpl.buildDialect(DialectFactoryImpl.java:87) ~[hibernate-core-6.5.2.Final.jar!/:6.5.2.Final]
2024-12-02 13:37:39     at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.getJdbcEnvironmentWithDefaults(JdbcEnvironmentInitiator.java:152) ~[hibernate-core-6.5.2.Final.jar!/:6.5.2.Final]
2024-12-02 13:37:39     at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.getJdbcEnvironmentUsingJdbcMetadata(JdbcEnvironmentInitiator.java:362) ~[hibernate-core-6.5.2.Final.jar!/:6.5.2.Final]
2024-12-02 13:37:39     at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:123) ~[hibernate-core-6.5.2.Final.jar!/:6.5.2.Final]
2024-12-02 13:37:39     at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:77) ~[hibernate-core-6.5.2.Final.jar!/:6.5.2.Final]
2024-12-02 13:37:39     at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.initiateService(StandardServiceRegistryImpl.java:130) ~[hibernate-core-6.5.2.Final.jar!/:6.5.2.Final]
2024-12-02 13:37:39     at org.hibernate.service.internal.AbstractServiceRegistryImpl.createService(AbstractServiceRegistryImpl.java:263) ~[hibernate-core-6.5.2.Final.jar!/:6.5.2.Final]
2024-12-02 13:37:39     ... 37 common frames omitted
2024-12-02 13:37:39 

I have tried using all the help, including several AIs, for no avail so far.
This is my Dockerfile:

FROM openjdk:17-jdk-slim
VOLUME /tmp
COPY target/*.jar app.jar
ENTRYPOINT ["java","-jar","/app.jar"]

This is my docker_compose.yaml:

version: '3.8'

services:
  app:
    build:
      context: .
      dockerfile: Dockerfile
    ports:
      - "8080:8080"
    depends_on:
      - db
    environment:
      SPRING_DATASOURCE_URL: jdbc:postgresql://192.168.0.104:5433/rungroopcourse
      SPRING_DATASOURCE_USERNAME: postgres
      SPRING_DATASOURCE_PASSWORD: postgres
      SPRING_JPA_HIBERNATE_DDL_AUTO: update
      SPRING_JPA_PROPERTIES_HIBERNATE_DIALECT: org.hibernate.dialect.PostgreSQLDialect

  db:
    image: postgres:15
    container_name: postgres3
    ports:
      - "5433:5433"
    environment:
      POSTGRES_DB: rungroopcourse
      POSTGRES_USER: postgres
      POSTGRES_PASSWORD: postgres
    volumes:
      - postgres-data:/var/lib/postgresql/data

volumes:
  postgres-data:

I have tried using both the containarized database at port 5435 and the native localhost database on port 5433. Both to no avail unfortunately, I always receive the same error. And I’ve also tried the in-memory database as mentioned.
Here goes my application.properties:

spring.application.name=web
spring.datasource.url=jdbc:postgresql://localhost:5433/rungroopcourse
spring.datasource.username=postgres
spring.datasource.password=postgres
spring.datasource.driver-class-name=org.postgresql.Driver
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.PostgreSQLDialect
spring.security.user.name=test
spring.security.user.password=test

spring.jpa.show-sql=true

# Enable session management
server.servlet.session.persistent=true
server.servlet.session.timeout=30m

# Debugging
logging.level.org.hibernate=DEBUG
logging.level.org.hibernate.SQL=DEBUG
logging.level.org.hibernate.type.descriptor.sql.BasicBinder=TRACE

jakarta.persistence.jdbc.url=jdbc:postgresql://localhost:5433/rungroopcourse



# Specify explicitly the dialect (here for PostgreSQL, adapt for your database)
spring.jpa.database-platform=org.hibernate.dialect.PostgreSQLDialect

# Disable Hibernate usage of JDBC metadata
spring.jpa.properties.hibernate.boot.allow_jdbc_metadata_access=false

# Database initialization should typically be performed outside of Spring lifecycle
spring.jpa.hibernate.ddl-auto=none
spring.sql.init.mode=never

# Allow Hikari Pool suspension
spring.datasource.hikari.allow-pool-suspension=true

Here goes the full updated code in a GitHub repo:
https://github.com/jaroslavchladek/kurabu.info

Kindly please for Your help.
Any idea why this might happen?
Thanks.