Post-processing to apply custom JdbcConnectionDetails triggers an NPE in Hikari if the JDBC URL is for an unknown driver

[wilkinsona]

The problem can be triggered with a bean like this:

@Bean
JdbcConnectionDetails jdbcConnectionDetails() {
	return new JdbcConnectionDetails() {

		@Override
		public String getUsername() {
			return "root";
		}

		@Override
		public String getPassword() {
			return "password";
		}

		@Override
		public String getJdbcUrl() {
			return "jdbc:example//localhost:1234/example";
		}

	};
}

It will result in a failure like this:

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaConfiguration.class]: Failed to initialize dependency 'dataSourceScriptDatabaseInitializer' of LoadTimeWeaverAware bean 'entityManagerFactory': Error creating bean with name 'dataSourceScriptDatabaseInitializer' defined in class path resource [org/springframework/boot/autoconfigure/sql/init/DataSourceInitializationConfiguration.class]: Unsatisfied dependency expressed through method 'dataSourceScriptDatabaseInitializer' parameter 0: Error creating bean with name 'dataSource' defined in class path resource [org/springframework/boot/autoconfigure/jdbc/DataSourceConfiguration$Hikari.class]: null
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:326) ~[spring-beans-6.1.18-SNAPSHOT.jar:6.1.18-SNAPSHOT]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:205) ~[spring-beans-6.1.18-SNAPSHOT.jar:6.1.18-SNAPSHOT]
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:954) ~[spring-context-6.1.18-SNAPSHOT.jar:6.1.18-SNAPSHOT]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:625) ~[spring-context-6.1.18-SNAPSHOT.jar:6.1.18-SNAPSHOT]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:146) ~[main/:na]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:754) ~[main/:na]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:456) ~[main/:na]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:335) ~[main/:na]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1363) ~[main/:na]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1352) ~[main/:na]
	at smoketest.data.jpa.SampleDataJpaApplication.main(SampleDataJpaApplication.java:28) ~[main/:na]
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'dataSourceScriptDatabaseInitializer' defined in class path resource [org/springframework/boot/autoconfigure/sql/init/DataSourceInitializationConfiguration.class]: Unsatisfied dependency expressed through method 'dataSourceScriptDatabaseInitializer' parameter 0: Error creating bean with name 'dataSource' defined in class path resource [org/springframework/boot/autoconfigure/jdbc/DataSourceConfiguration$Hikari.class]: null
	at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:795) ~[spring-beans-6.1.18-SNAPSHOT.jar:6.1.18-SNAPSHOT]
	at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:542) ~[spring-beans-6.1.18-SNAPSHOT.jar:6.1.18-SNAPSHOT]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1355) ~[spring-beans-6.1.18-SNAPSHOT.jar:6.1.18-SNAPSHOT]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1185) ~[spring-beans-6.1.18-SNAPSHOT.jar:6.1.18-SNAPSHOT]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:562) ~[spring-beans-6.1.18-SNAPSHOT.jar:6.1.18-SNAPSHOT]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:522) ~[spring-beans-6.1.18-SNAPSHOT.jar:6.1.18-SNAPSHOT]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:337) ~[spring-beans-6.1.18-SNAPSHOT.jar:6.1.18-SNAPSHOT]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-6.1.18-SNAPSHOT.jar:6.1.18-SNAPSHOT]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:335) ~[spring-beans-6.1.18-SNAPSHOT.jar:6.1.18-SNAPSHOT]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:200) ~[spring-beans-6.1.18-SNAPSHOT.jar:6.1.18-SNAPSHOT]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:313) ~[spring-beans-6.1.18-SNAPSHOT.jar:6.1.18-SNAPSHOT]
	... 10 common frames omitted
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSource' defined in class path resource [org/springframework/boot/autoconfigure/jdbc/DataSourceConfiguration$Hikari.class]: null
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:607) ~[spring-beans-6.1.18-SNAPSHOT.jar:6.1.18-SNAPSHOT]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:522) ~[spring-beans-6.1.18-SNAPSHOT.jar:6.1.18-SNAPSHOT]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:337) ~[spring-beans-6.1.18-SNAPSHOT.jar:6.1.18-SNAPSHOT]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-6.1.18-SNAPSHOT.jar:6.1.18-SNAPSHOT]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:335) ~[spring-beans-6.1.18-SNAPSHOT.jar:6.1.18-SNAPSHOT]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:200) ~[spring-beans-6.1.18-SNAPSHOT.jar:6.1.18-SNAPSHOT]
	at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:254) ~[spring-beans-6.1.18-SNAPSHOT.jar:6.1.18-SNAPSHOT]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1448) ~[spring-beans-6.1.18-SNAPSHOT.jar:6.1.18-SNAPSHOT]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1358) ~[spring-beans-6.1.18-SNAPSHOT.jar:6.1.18-SNAPSHOT]
	at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:904) ~[spring-beans-6.1.18-SNAPSHOT.jar:6.1.18-SNAPSHOT]
	at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:782) ~[spring-beans-6.1.18-SNAPSHOT.jar:6.1.18-SNAPSHOT]
	... 20 common frames omitted
Caused by: java.lang.NullPointerException: null
	at java.base/java.util.concurrent.ConcurrentHashMap.putVal(ConcurrentHashMap.java:1011) ~[na:na]
	at java.base/java.util.concurrent.ConcurrentHashMap.putIfAbsent(ConcurrentHashMap.java:1541) ~[na:na]
	at java.base/java.lang.ClassLoader.getClassLoadingLock(ClassLoader.java:671) ~[na:na]
	at java.base/jdk.internal.loader.BuiltinClassLoader.loadClassOrNull(BuiltinClassLoader.java:651) ~[na:na]
	at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:639) ~[na:na]
	at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:188) ~[na:na]
	at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:525) ~[na:na]
	at com.zaxxer.hikari.HikariConfig.attemptFromContextLoader(HikariConfig.java:973) ~[HikariCP-5.1.0.jar:na]
	at com.zaxxer.hikari.HikariConfig.setDriverClassName(HikariConfig.java:483) ~[HikariCP-5.1.0.jar:na]
	at org.springframework.boot.autoconfigure.jdbc.HikariJdbcConnectionDetailsBeanPostProcessor.processDataSource(HikariJdbcConnectionDetailsBeanPostProcessor.java:42) ~[main/:na]
	at org.springframework.boot.autoconfigure.jdbc.HikariJdbcConnectionDetailsBeanPostProcessor.processDataSource(HikariJdbcConnectionDetailsBeanPostProcessor.java:1) ~[main/:na]
	at org.springframework.boot.autoconfigure.jdbc.JdbcConnectionDetailsBeanPostProcessor.postProcessBeforeInitialization(JdbcConnectionDetailsBeanPostProcessor.java:55) ~[main/:na]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsBeforeInitialization(AbstractAutowireCapableBeanFactory.java:422) ~[spring-beans-6.1.18-SNAPSHOT.jar:6.1.18-SNAPSHOT]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1798) ~[spring-beans-6.1.18-SNAPSHOT.jar:6.1.18-SNAPSHOT]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:600) ~[spring-beans-6.1.18-SNAPSHOT.jar:6.1.18-SNAPSHOT]
	... 30 common frames omitted

HikariJdbcConnectionDetailsBeanPostProcessor should not try to set the driver class name when it's null.