Spring Boot Error: Injection of Resource Dependencies Failed for UserController, UserService, and UserDao

This error indicates that there is a problem with dependency injection in the 'userController' bean. Specifically, there is a problem injecting the 'userService' bean, which in turn has a problem injecting the 'userDao' bean.

The root cause of the problem is likely an issue with the configuration of the Spring application context. It appears that Spring is unable to properly manage the 'User' entity class in the 'userDao' bean.

To resolve this issue, you may need to check your configuration files and ensure that the 'User' entity class is properly registered with Spring's JPA configuration. Additionally, you may need to ensure that all necessary dependencies are properly declared and injected throughout your application.