private void loginByUser(String username, HttpServletRequest request) {
    // 查询数据库，看用户是否存在
    User userInDb = userDao.findByUsername(username);
    if (userInDb != null) {
        // 放入session
        LOGGER.info("User: {} succeed to login", username);
        loginService.addToSession(username, request);
    } else {
        // 自动创建用户
        LOGGER.warn("user: {}, do not exist, trying to create user", username);
        try {
            userService.autoAddUser(username);
            loginService.addToSession(username, request);
        } catch (RoleNotFoundException e) {
            LOGGER.error("Failed to auto add user, cause by: Failed to get role [PROJECTOR]", e);
        }
    }

}
 

@Override
@Transactional(rollbackFor = {Exception.class})
public void autoAddUser(String username) throws RoleNotFoundException {
    User newUser = new User();
    String password = username;
    String passwordEncoded = Sha256Encoder.encode(password);
    newUser.setUsername(username);
    newUser.setPassword(passwordEncoded);
    User savedUser = userDao.saveUser(newUser);

    Role role = roleDao.findByRoleName("PROJECTOR");
    if (role == null) {
        throw new RoleNotFoundException();
    }
    UserRole userRole = new UserRole();
    userRole.setId(UuidGenerator.generate());
    userRole.setRole(role);
    userRole.setUser(savedUser);
    userRoleDao.saveUserRole(userRole);
    LOGGER.info("Succeed to save user_role. uuid: {}, user_id: {}, role_id: {}", userRole.getId(), savedUser.getId(), role.getId());
}
 

/**
 * Auto register user
 * @param username
 * @throws RoleNotFoundException
 */
void autoAddUser(String username) throws RoleNotFoundException;