springboot spring.db.datasource.driver-class-name is not used by HikariCP

While migrating from Spring Boot 1.x to Spring 2.x getting following error while bootstrapping the application.

Invocation of init method failed; nested exception is javax.persistence.PersistenceException: [PersistenceUnit: dbPU] Unable to build Hibernate SessionFactory; nested exception is java.lang.IllegalArgumentException: jdbcUrl is required with driverClassName.
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredMethodElement.inject(AutowiredAnnotationBeanPostProcessor.java:723) ~[spring-beans-5.2.3.RELEASE.jar!/:5.2.3.RELEASE]
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:116) ~[spring-beans-5.2.3.RELEASE.jar!/:5.2.3.RELEASE]
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:399) ~[spring-beans-5.2.3.RELEASE.jar!/:5.2.3.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1422) ~[spring-beans-5.2.3.RELEASE.jar!/:5.2.3.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:594) ~[spring-beans-5.2.3.RELEASE.jar!/:5.2.3.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517) ~[spring-beans-5.2.3.RELEASE.jar!/:5.2.3.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:323) ~[spring-beans-5.2.3.RELEASE.jar!/:5.2.3.RELEASE]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.2.3.RELEASE.jar!/:5.2.3.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:321) ~[spring-beans-5.2.3.RELEASE.jar!/:5.2.3.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-5.2.3.RELEASE.jar!/:5.2.3.RELEASE]
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:409) ~[spring-beans-5.2.3.RELEASE.jar!/:5.2.3.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1338) ~[spring-beans-5.2.3.RELEASE.jar!/:5.2.3.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1177) ~[spring-beans-5.2.3.RELEASE.jar!/:5.2.3.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:557) ~[spring-beans-5.2.3.RELEASE.jar!/:5.2.3.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517) ~[spring-beans-5.2.3.RELEASE.jar!/:5.2.3.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:323) ~[spring-beans-5.2.3.RELEASE.jar!/:5.2.3.RELEASE]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.2.3.RELEASE.jar!/:5.2.3.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:321) ~[spring-beans-5.2.3.RELEASE.jar!/:5.2.3.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-5.2.3.RELEASE.jar!/:5.2.3.RELEASE]
    at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:276) ~[spring-beans-5.2.3.RELEASE.jar!/:5.2.3.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1287) ~[spring-beans-5.2.3.RELEASE.jar!/:5.2.3.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1207) ~[spring-beans-5.2.3.RELEASE.jar!/:5.2.3.RELEASE]
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredMethodElement.inject(AutowiredAnnotationBeanPostProcessor.java:715) ~[spring-beans-5.2.3.RELEASE.jar!/:5.2.3.RELEASE]
    ... 70 common frames omitted

My current configuration:

spring.db.datasource.url=jdbc:mysql://localhost:3306/myDB?useUnicode=yes&characterEncoding=UTF-8&rewriteBatchedStatements=true&serverTimezone=PST
spring.db.datasource.username=
spring.db.datasource.password=
spring.db.datasource.driver-class-name=com.mysql.cj.jdbc.Driver

Though spring.db.datasource.driver-class-name is defined HikariCP is not able to find driverClassName

Comment From: snicoll

The migration to Spring Boot 2 changed the default connection pool (from Tomcat to Hikari) and the latter does not have an url property. You are configuring the DataSource yourself so you need to take care of that.

There is an existing StackOverflow thread with a number of replies that point you to this direction. See also the reference documentation that has a note about Hikari and its jdbc-url.