org.springframework.security.authentication.InternalAuthenticationServiceException | UserDetailsService returned null

org.springframework.security.authentication.InternalAuthenticationServiceE

xception: UserDetailsService returned null, which is an interface contract 

violation\r\n\tat 

org.springframework.security.authentication.dao.DaoAuthenticationProvider

.retrieveUser(DaoAuthenticationProvider.java:110)\r\n\tat 

org.springframework.security.authentication.dao.AbstractUserDetailsAuthen

ticationProvider.authenticate

(AbstractUserDetailsAuthenticationProvider.java:144)\r\n\tat 

org.springframework.security.authentication.ProviderManager.authenticate

(ProviderManager.java:175)\r\n\tat 

org.springframework.security.authentication.ProviderManager.authenticate

(ProviderManager.java:195)

Solution

if your service class is implementing org.springframework.security.core.userdetails.UserDetailsService

you should implement loadUserByUsername()

and returns a new User(username,pass,rolesList)

public class yourServiceClass implements UserDetailsService {

//unimplemented method

loadUserByUsername(){

return new User(x,y,z);

}}