Default Spring Boot Error Page

Occurred: Fri Sep 21 05:19:39 HKT 2018

Response Status: 500 (Internal Server Error)

Cause: org.springframework.transaction.CannotCreateTransactionException Request processing failed; nested exception is org.springframework.transaction.CannotCreateTransactionException: Could not open JPA EntityManager for transaction; nested exception is javax.persistence.PersistenceException: org.hibernate.exception.GenericJDBCException: Could not open connection
Note: You would never generate a page that displays a Java exception to an end-user in a real application

You are seeing this error page due to Spring Boot (which returns a view called "error" in response to uncaught exceptions. Since we are using Thymeleaf this corresponds to the template error.html )