shiro系列三、定义Realm

自定义realm；

/**
 * 认证和授权
 */
@Component
public class UserRealm extends AuthorizingRealm {

    @Autowired
    private UserService userService;
    @Autowired
    private AuthService authService;

    /**
     * 授权(验证权限时调用)
     */
    @Override
    protected AuthorizationInfo doGetAuthorizationInfo(PrincipalCollection principals) {
        User user = (User)principals.getPrimaryPrincipal();
        Integer userId = user.getUserId();
        List<String> permsList = null;

        //系统管理员，拥有最高权限
        if(userId == ){
            List<Auth> menuList = authService.queryList(new HashMap<String, Object>());
            permsList = new ArrayList<String>(menuList.size());
            for(Auth menu : menuList){
                permsList.add(menu.getPerms());
            }
        }else{
            permsList = userService.queryAllPerms(userId);
        }
        //用户权限列表
        Set<String> permsSet = new HashSet<String>();
        for(String perms : permsList){
            if(StringUtils.isBlank(perms)){
                continue;
            }
            permsSet.addAll(Arrays.asList(perms.trim().split(",")));
        }

        SimpleAuthorizationInfo info = new SimpleAuthorizationInfo();
        info.setStringPermissions(permsSet);
        return info;
    }

    /**
     * 认证(登录时调用)
     */
    @Override
    protected AuthenticationInfo doGetAuthenticationInfo(
            AuthenticationToken authcToken) throws AuthenticationException {
        UsernamePasswordToken token = (UsernamePasswordToken)authcToken;

        //查询用户信息
        User user = userService.queryByUserName(token.getUsername());
        //账号不存在
        if(user == null) {
            throw new UnknownAccountException("账号不存在");
        }
        SimpleAuthenticationInfo info =null;
        info = new SimpleAuthenticationInfo(user, user.getPassword(), ByteSource.Util.bytes(user.getSalt()),getName());
        return info;
    }

    @Override
    public void setCredentialsMatcher(CredentialsMatcher credentialsMatcher) {
        HashedCredentialsMatcher shaCredentialsMatcher = new CustomUserMatche();
        shaCredentialsMatcher.setHashAlgorithmName(ShiroUtils.hashAlgorithmName);
        shaCredentialsMatcher.setHashIterations(ShiroUtils.hashIterations);
        super.setCredentialsMatcher(shaCredentialsMatcher);
    }
}

1、UserRealm父类AuthorizingRealm将获取Subject相关信息分成两步：获取身份验证信息（doGetAuthenticationInfo）及授权信息（doGetAuthorizationInfo）；

2、doGetAuthenticationInfo获取身份验证相关信息：首先根据传入的用户名获取User信息；然后如果user为空，那么抛出没找到帐号异常UnknownAccountException；如果user找到但锁定了抛出锁定异常LockedAccountException；最后生成AuthenticationInfo信息，交给间接父类AuthenticatingRealm使用CredentialsMatcher进行判断密码是否匹配，如果不匹配将抛出密码错误异常IncorrectCredentialsException；另外如果密码重试此处太多将抛出超出重试次数异常ExcessiveAttemptsException；在组装SimpleAuthenticationInfo信息时，需要传入：身份信息（用户名）、凭据（密文密码）、盐（username+salt），CredentialsMatcher使用盐加密传入的明文密码和此处的密文密码进行匹配。

3、doGetAuthorizationInfo获取授权信息：PrincipalCollection是一个身份集合，因为我们现在就一个Realm，所以直接调用getPrimaryPrincipal得到之前传入的用户名即可；然后根据用户名调用UserService接口获取角色及权限信息。