UserService.java

package com.qprogramming.tasq.account;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
import org.springframework.security.core.Authentication;
import org.springframework.security.core.GrantedAuthority;
import org.springframework.security.core.authority.SimpleGrantedAuthority;
import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.security.core.userdetails.UserDetailsService;
import org.springframework.security.core.userdetails.UsernameNotFoundException;

import java.util.Collections;

public class UserService implements UserDetailsService {
    private static final Logger LOG = LoggerFactory.getLogger(UserService.class);

    @Autowired
    private AccountService accountSrv;

    @Override
    public UserDetails loadUserByUsername(String username) throws UsernameNotFoundException {
        Account account = accountSrv.findByEmail(username);
        // try to find by username
        if (account == null) {
            account = accountSrv.findByUsername(username);
        }
        if (account == null) {
            LOG.error("User not found or not confirmed registration.");
            throw new UsernameNotFoundException("User not found or is not confirmed");
        }
        account.setAuthority(account.getRole());
        return account;
    }

    public void signin(Account account) {
        SecurityContextHolder.getContext().setAuthentication(authenticate(account));
    }

    private Authentication authenticate(Account account) {
        return new UsernamePasswordAuthenticationToken(account, null, Collections.singleton(createAuthority(account)));
    }

    private GrantedAuthority createAuthority(Account account) {
        return new SimpleGrantedAuthority(account.getRole().toString());
    }

}