/** 获取用户Details信息的回调函数. */
  public UserDetails loadUserByUsername(String userName)
      throws UsernameNotFoundException, DataAccessException {

    User user = userManager.findUserByLoginName(userName);
    if (user == null) {
      throw new UsernameNotFoundException("用户" + userName + " 不存在");
    }
    boolean enabled = true;
    if (user.getStatus() == 0) {
      enabled = false;
      throw new UsernameNotFoundException("用户" + userName + " 未激活");
    }
    GrantedAuthority[] grantedAuths = obtainGrantedAuthorities(user);

    boolean accountNonExpired = true;
    boolean credentialsNonExpired = true;
    boolean accountNonLocked = true;

    org.springframework.security.userdetails.User userdetail =
        new org.springframework.security.userdetails.User(
            user.getEmail(),
            user.getPassword(),
            enabled,
            accountNonExpired,
            credentialsNonExpired,
            accountNonLocked,
            grantedAuths);

    return userdetail;
  }
 /** 获得用户所有角色的权限集合. */
 private GrantedAuthority[] obtainGrantedAuthorities(User user) {
   Set<GrantedAuthority> authSet = new HashSet<GrantedAuthority>();
   for (Role role : user.getRoles()) {
     authSet.add(new GrantedAuthorityImpl(role.getRole_name()));
   }
   return authSet.toArray(new GrantedAuthority[authSet.size()]);
 }