userDetailsService in com.seguranca.config.ResourceServerConfig required a bean of type 'org.springframework.security.core.userdetails.UserDetailsService'

Pessoal, estou implementando spring security, porém quando starto a aplicação dá o erro abaixo:


APPLICATION FAILED TO START


Description:

Field userDetailsService in com.seguranca.config.ResourceServerConfig required a bean of type ‘org.springframework.security.core.userdetails.UserDetailsService’ that could not be found.
Action:

Consider defining a bean of type ‘org.springframework.security.core.userdetails.UserDetailsService’ in your configuration.