spring-boot集成spring-security的oauth2实现github登录网站的示例

<dependency>
 <groupId>org.springframework.security.oauth</groupId>
 <artifactId>spring-security-oauth2</artifactId>
</dependency>

security:
 oauth2:
  client:
   client-id:
   client-secret:
   accessTokenUri: https://github.com/login/oauth/access_token
   userAuthorizationUri: https://github.com/login/oauth/authorize
   clientAuthenticationScheme: form
   registered-redirect-uri: ${site.baseUrl}/github_login
   use-current-uri: false
  resource:
   userInfoUri: https://api.github.com/user
  sso:
   login-path: /github_login

@Bean
public PrincipalExtractor principalExtractor() {
 return map -> {
  String login = map.get("login").toString();//github的登录名
  GithubUser githubUser = githubUserService.findByLogin(login);
  User user;
  if (githubUser == null) {
   githubUser = new GithubUser();
   githubUser = githubUserService.convert(map, githubUser);
   //创建一个本地用户
   user = userService.findByUsername(login);
   if (user == null) {
    user = new User();
    user.setUsername(login);
   } else {
    user.setUsername(login + "_" + githubUser.getGithubId());
   }
   user.setEmail(githubUser.getEmail());
   user.setBio(githubUser.getBio());
   user.setUrl(githubUser.getHtml_url());
   user.setPassword(new BCryptPasswordEncoder().encode(StrUtil.randomString(16)));
   user.setInTime(new Date());
   user.setBlock(false);
   user.setToken(UUID.randomUUID().toString());
   user.setAvatar(githubUser.getAvatar_url());
   user.setAttempts(0);
   user.setScore(2000);// first register score 2000
   user.setSpaceSize(siteConfig.getUserUploadSpaceSize());
   user.setGithubUser(githubUser);

   // set user's role
   Role role = roleService.findById(3); // normal user
   Set roles = new HashSet();
   roles.add(role);
   user.setRoles(roles);
   userService.save(user);
  } else {
   githubUser = githubUserService.convert(map, githubUser);
   user = githubUser.getUser();
   githubUserService.save(githubUser);
  }
  //加载用户的权限信息
  return yiiuUserDetailService.loadUserByUsername(user.getUsername());
 };
}

@Service
public class YiiuUserDetailService implements UserDetailsService {

 private Logger log = Logger.getLogger(YiiuUserDetailService.class);

 @Autowired
 private UserService userService;
 @Autowired
 private PermissionService permissionService;

 public UserDetails loadUserByUsername(String username) {
  User user = userService.findByUsername(username);
  if (user != null) {
   List<Permission> permissions = permissionService.findByAdminUserId(user.getId());
   List<GrantedAuthority> grantedAuthorities = new ArrayList<>();
   for (Permission permission : permissions) {
    GrantedAuthority grantedAuthority = new SimpleGrantedAuthority(permission.getName());
    grantedAuthorities.add(grantedAuthority);
   }
   return new org.springframework.security.core.userdetails.User(user.getUsername(), user.getPassword(),
     true, true, true, !user.isBlock(), grantedAuthorities);
  } else {
   log.info("用户" + username + " 不存在");
   throw new UsernameNotFoundException("用户名或密码不正确");
  }
 }

}