Consider defining a bean of type 'com.example.user.dao.UserDao' in your configuration.

This error message typically occurs when Spring is unable to find a bean of type 'com.example.user.dao.UserDao' during application startup. To resolve this issue, you need to make sure that you have defined a bean of type 'com.example.user.dao.UserDao' in your Spring configuration file.

There are several ways to define a bean in Spring, but one common way is to use the @ComponentScan annotation to scan for classes with the @Component annotation and register them as beans. Alternatively, you can use the @Bean annotation to define a bean method in a configuration class.

For example, if you have a UserDaoImpl class that implements UserDao interface, you can define a bean of type UserDao in your Spring configuration file as follows:

@Configuration
public class AppConfig {
 
    @Bean
    public UserDao userDao() {
        return new UserDaoImpl();
    }
}

This will register an instance of UserDaoImpl as a bean of type UserDao, which can then be autowired into other beans that require a UserDao.