SpringCloudGateway网关实战（三）

上一章节我们讲了gateway的内置过滤器Filter，本章节我们来讲讲全局过滤器。

自带全局过滤器

在实现自定义全局过滤器前， spring-cloud-starter-gateway依赖本身就自带一些全局过滤器，我们举些比较常用的例子：

1. NettyRoutingFilter：该过滤器使用Netty作为底层的HTTP客户端，负责将请求转发到下游服务。
2. RouteToRequestUrlFilter：该过滤器将根据路由配置中的URI信息，将请求转发到指定的URL。
3. WebsocketRoutingFilter：该过滤器用于处理WebSocket协议的请求转发。
4. GatewayMetricsFilter：该过滤器用于收集网关的基本性能指标数据，例如请求的数量、响应时间等。

自定义全局过滤器

自定义全局过滤器需要实现GlobalFilter接口和Ordered接口。

AuthFilter

token验证全局过滤器

引入依赖：

        <!-- Jwt --><dependency><groupId>io.jsonwebtoken</groupId><artifactId>jjwt</artifactId><version>0.9.1</version></dependency>

具体代码：

@Component
public class AuthFilter implements GlobalFilter, Ordered {private static final Logger log = LoggerFactory.getLogger(AuthFilter.class);@Autowiredprivate IgnoreWhiteProperties ignoreWhite;@Autowiredpublic RedisTemplate redisTemplate;@Overridepublic Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {ServerHttpRequest request = exchange.getRequest();ServerHttpRequest.Builder mutate = request.mutate();// 跳过白名单String url = request.getURI().getPath();if (com.smallred.gateway.utils.StringUtils.matches(url, ignoreWhite.getWhites())) {return chain.filter(exchange);}// 检查令牌是否存在String token = getToken(request);if (StringUtils.isEmpty(token)) {return unauthorizedResponse(exchange, "令牌不能为空!");}//Claims claims = JwtUtils.parseToken(token);if (claims == null) {return unauthorizedResponse(exchange, "令牌已过期或验证不正确！");}// 判断登录状态String userKey = JwtUtils.getUserKey(claims);Boolean islogin = redisTemplate.hasKey(getTokenKey(userKey));if (!islogin) {return unauthorizedResponse(exchange, "登录状态已过期!");}// 验证用户信息String userId = JwtUtils.getUserId(claims);String userName = JwtUtils.getUserName(claims);if (StringUtils.isEmpty(userId) || StringUtils.isEmpty(userName)) {return unauthorizedResponse(exchange, "令牌验证失败");}// 设置用户信息到请求addHeader(mutate, "user_key", userKey);addHeader(mutate, "user_id", userId);addHeader(mutate, "username", userName);// 内部请求来源参数清除removeHeader(mutate, "from-source");return chain.filter(exchange.mutate().request(mutate.build()).build());}/***  添加头*/private void addHeader(ServerHttpRequest.Builder mutate, String name, Object value) {if (value == null) {return;}String valueStr = value.toString();String valueEncode = urlEncode(valueStr);mutate.header(name, valueEncode);}/***  删除头*/private void removeHeader(ServerHttpRequest.Builder mutate, String name) {mutate.headers(httpHeaders -> httpHeaders.remove(name)).build();}/***  获取缓存key*/private String getTokenKey(String token) {return "login_tokens:" + token;}/***  获取请求token*/private String getToken(ServerHttpRequest request) {String token = request.getHeaders().getFirst("Authorization");// 如果前端设置了令牌前缀，则裁剪掉前缀if (StringUtils.isNotEmpty(token) && token.startsWith("Bearer")) {token = token.replaceFirst("Bearer", StringUtils.EMPTY);}return token;}/*** 内容编码** @param str 内容* @return 编码后的内容*/public static String urlEncode(String str){try{return URLEncoder.encode(str, "UTF-8");}catch (UnsupportedEncodingException e){return StringUtils.EMPTY;}}/***  验证失败返回*/private Mono<Void> unauthorizedResponse(ServerWebExchange exchange, String msg) {log.error("[鉴权异常处理]请求路径:{}", exchange.getRequest().getPath());return ServletUtils.webFluxResponseWriter(exchange.getResponse(), msg, 401);}@Overridepublic int getOrder() {return -200;}
}

依赖类

白名单：

@Configuration
@RefreshScope
@ConfigurationProperties(prefix = "security.ignore")
public class IgnoreWhiteProperties {private List<String> whites = new ArrayList<>();public List<String> getWhites() {return whites;}public void setWhites(List<String> whites) {this.whites = whites;}
}

白名单配置：

# 安全配置
security:ignore:whites:- /auth/logout- /auth/login- /auth/register- /*/v2/api-docs- /csrf

StringUtils类：

public class StringUtils {/** 空字符串 */private static final String NULLSTR = "";public static boolean matches(String str, List<String> strs){if (isEmpty(str) || isEmpty(strs)){return false;}for (String pattern : strs){if (isMatch(pattern, str)){return true;}}return false;}public static boolean isEmpty(String str){return isNull(str) || NULLSTR.equals(str.trim());}public static boolean isEmpty(Collection<?> coll){return isNull(coll) || coll.isEmpty();}public static boolean isNull(Object object){return object == null;}public static boolean isMatch(String pattern, String url){AntPathMatcher matcher = new AntPathMatcher();return matcher.match(pattern, url);}}

ServletUtils类：

public class ServletUtils {public static Mono<Void> webFluxResponseWriter(ServerHttpResponse response, Object value, int code){return webFluxResponseWriter(response, HttpStatus.OK, value, code);}public static Mono<Void> webFluxResponseWriter(ServerHttpResponse response, HttpStatus status, Object value, int code){return webFluxResponseWriter(response, MediaType.APPLICATION_JSON_VALUE, status, value, code);}public static Mono<Void> webFluxResponseWriter(ServerHttpResponse response, String contentType, HttpStatus status, Object value, int code){response.setStatusCode(status);response.getHeaders().add(HttpHeaders.CONTENT_TYPE, contentType);R<?> result = R.fail(code, value.toString());DataBuffer dataBuffer = response.bufferFactory().wrap(JSON.toJSONString(result).getBytes());return response.writeWith(Mono.just(dataBuffer));}}

JwtUtils类：

public class JwtUtils {public static String secret = "abcdefghijklmnopqrstuvwxyz";/*** 从数据声明生成令牌** @param claims 数据声明* @return 令牌*/public static String createToken(Map<String, Object> claims){String token = Jwts.builder().setClaims(claims).signWith(SignatureAlgorithm.HS512, secret).compact();return token;}/*** 从令牌中获取数据声明** @param token 令牌* @return 数据声明*/public static Claims parseToken(String token){return Jwts.parser().setSigningKey(secret).parseClaimsJws(token).getBody();}/*** 根据令牌获取用户标识** @param token 令牌* @return 用户ID*/public static String getUserKey(String token){Claims claims = parseToken(token);return getValue(claims, "user_key");}/*** 根据令牌获取用户标识** @param claims 身份信息* @return 用户ID*/public static String getUserKey(Claims claims){return getValue(claims, "user_key");}/*** 根据令牌获取用户ID** @param token 令牌* @return 用户ID*/public static String getUserId(String token){Claims claims = parseToken(token);return getValue(claims, "user_id");}/*** 根据身份信息获取用户ID** @param claims 身份信息* @return 用户ID*/public static String getUserId(Claims claims){return getValue(claims, "user_id");}/*** 根据令牌获取用户名** @param token 令牌* @return 用户名*/public static String getUserName(String token){Claims claims = parseToken(token);return getValue(claims, "username");}/*** 根据身份信息获取用户名** @param claims 身份信息* @return 用户名*/public static String getUserName(Claims claims){return getValue(claims, "username");}/*** 根据身份信息获取键值** @param claims 身份信息* @param key 键* @return 值*/public static String getValue(Claims claims, String key){return toStr(claims.get(key), "");}public static String toStr(Object value, String defaultValue){if (null == value){return defaultValue;}if (value instanceof String){return (String) value;}return value.toString();}}

IpAddressFilter

根据请求记录ip地址日志：

@Component
public class IpAddressFilter implements GlobalFilter, Ordered {public static final Map<String, AtomicInteger> CACHE = new ConcurrentHashMap<>();@Overridepublic Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {InetSocketAddress host = exchange.getRequest().getHeaders().getHost();if (host == null || host.getHostName() == null) {exchange.getResponse().setStatusCode(HttpStatus.BAD_REQUEST);return exchange.getResponse().setComplete();}String hostName = host.getHostName();AtomicInteger count = CACHE.getOrDefault(hostName, new AtomicInteger(0));count.incrementAndGet();CACHE.put(hostName, count);System.out.println("IP地址：" + hostName + ",访问次数：" + count.intValue());return chain.filter(exchange);}@Overridepublic int getOrder() {return 101;}
}