MyUserDetailService.java

package com.springoauth2.demo.config;

import com.springoauth2.demo.entity.User;
import com.springoauth2.demo.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.security.config.annotation.authentication.builders.AuthenticationManagerBuilder;
import org.springframework.security.config.annotation.authentication.configurers.GlobalAuthenticationConfigurerAdapter;
import org.springframework.security.core.authority.AuthorityUtils;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.security.core.userdetails.UserDetailsService;
import org.springframework.security.core.userdetails.UsernameNotFoundException;

/**
 * Created by wuhuachuan on 16/5/12.
 */
@Configuration
public class MyUserDetailService extends GlobalAuthenticationConfigurerAdapter {

    @Autowired
    private UserService userService;

    @Override
    public void init(AuthenticationManagerBuilder auth) throws Exception {
        auth.userDetailsService(userDetailsService());
    }

    @Bean
    public UserDetailsService userDetailsService() {
        return new UserDetailsService() {
            @Override
            public UserDetails loadUserByUsername(String username) throws UsernameNotFoundException {

                User user = userService.findByUsername(username);

                if(user != null){
                    return new org.springframework.security.core.userdetails.User(
                            user.getUsername(),
                            user.getPassword(),
                            true,
                            true,
                            true,
                            true,
                            AuthorityUtils.createAuthorityList("USER")
                    );
                } else {
                    throw new UsernameNotFoundException("could not find the user '"
                            + username + "'");
                }
            }
        };
    }
}