1 简介

简单理解---业务服务的统一入口，方便实现，服务路由，安全，限流，过滤，黑白名单，证书加密解密，服务降级/熔断，灰度，等等

2 介绍

1. Predicate（断言）：如果请求路径与断言相匹配则进行路由。(路径匹配是常见断言)
2. Route（路由）：路由是构建网关的基本模块，它由ID，目标URI，一系列的断言和过滤器组成，如果断言为true则匹配该路由。
3. Filter（过滤）：指的是Spring框架中GatewayFilter的实例，使用过滤器，路由成功，则可以执行pre Filter  ，服务响应回数据，可以执行 Post Filter。

3 注意事项

3.1

spring-boot-starter-parent和spring-cloud-starter-gateway版本要一致，否则可能报错

4 基本路由实战

4.1 pom文件

 <parent><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-parent</artifactId><version>2.1.3.RELEASE</version><relativePath/> <!-- lookup parent from repository --></parent><groupId>com.gateway</groupId><artifactId>gateway</artifactId><version>0.0.1-SNAPSHOT</version><packaging>war</packaging><name>gateway</name><description>Demo project for Spring Boot</description><properties><java.version>1.8</java.version><spring-cloud.version>2.1.3.RELEASE</spring-cloud.version></properties><dependencies><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId></dependency><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-gateway</artifactId><version>${spring-cloud.version}</version></dependency><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId><version>${spring-cloud.version}</version></dependency></dependencies>

 配置文件

server:port: 80
spring:application:name: gatewaycloud:nacos:discovery:server-addr: 127.0.0.1:8848# config:#   server-addr: localhost:8848 # Nacos 服务器地址gateway:routes:- id: goods-server #路由的ID，没有固定规则但要求唯一，建议配合服务名# uri: http://localhost:8001          #匹配后提供服务的路由地址uri: lb://goods-server      #匹配后提供服务的路由地址，lb负载predicates:- Path=/goods/**     # 断言，路径相匹配的进行路由- id: order-serveruri: lb://order-serverpredicates:- Path=/order/**#- Path=/goods/,/goods/** 多个可以逗号隔开enabled: true #开启网关，默认true 如果程序引用了spring-cloud-starter-gateway，但不希望启用网关 设置为false

4.2 测试路由转发

另外一个 goods 服务，直接访问 http://localhost:8080/goods/good/list 即可出现数据

 直接访问gateway服务 http://localhost/goods/good/list 自己就会转发到goods服务上

4.3 StripPrefix

有一种场景，前端会在所有的接口前加一个api。前端请求的路径是 http://localhost/api/goods/good/list  。实际上请求 http://localhost/goods/good/list 怎么办

StripPrefix=1的意思就是去掉路径上第一个，也就是api将会去掉。 当我们访问。http://localhost/api/goods/good/list  它会自动变成  http://localhost/goods/good/list

5 限流

  添加 pom坐标

        <dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-data-redis-reactive</artifactId></dependency>

注意点：

配置文件中 redis-rate-limiter.replenishRate ，redis-rate-limiter.burstCapacity等同于配置bean中的 RedisRateLimiter，但是同时存在时，只有配置文件的配置生效。

server:port: 80
spring:application:name: gatewaycloud:nacos:discovery:server-addr: 127.0.0.1:8848# config:#   server-addr: localhost:8848 # Nacos 服务器地址gateway:routes:- id: goods-server #路由的ID，没有固定规则但要求唯一，建议配合服务名# uri: http://localhost:8001          #匹配后提供服务的路由地址uri: lb://goods-server      #匹配后提供服务的路由地址predicates:- Path=/goods/**     # 断言，路径相匹配的进行路由filters:- name: RequestRateLimiterargs:#spel表达式 它会去容器查找名称为hostKeyResolver 的Bean。key-resolver: '#{@hostKeyResolver}'#针对同一个key，允许的每秒请求数，不包括被抛弃的请求。这实际是令牌桶填充率。redis-rate-limiter.replenishRate: 1#针对同一个key，一秒内允许的最大请求数。这实际是令牌桶可容纳的最大令牌数。若设为0，则拒绝所有请求。redis-rate-limiter.burstCapacity: 1

package com.order.config;import lombok.extern.slf4j.Slf4j;
import org.springframework.cloud.gateway.filter.ratelimit.KeyResolver;
import org.springframework.cloud.gateway.filter.ratelimit.RedisRateLimiter;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import reactor.core.publisher.Mono;import java.util.Objects;/*** @创建人 赵伟* @创建时间 2024/3/18* @描述*/
@Slf4j
@Configuration
public class RouteConfig {
/*    @Beanpublic KeyResolver userKeyResolver() {return exchange -> Mono.just(exchange.getRequest().getQueryParams().getFirst("userId")//exchange.getRequest().getHeaders().getFirst("X-Forwarded-For") 基于请求ip的限流);}*/
/*    *//*** 根据 路径 进行限流** @return KeyResolver*//*@Beanpublic KeyResolver pathKeyResolver() {return exchange -> Mono.just(Objects.requireNonNull(exchange.getRequest().getPath()).toString());}*//*** 根据 HostAddress 进行限流** @return KeyResolver*/@Beanpublic KeyResolver hostKeyResolver() {return exchange -> Mono.just(Objects.requireNonNull(exchange.getRequest().getRemoteAddress()).getHostString());}/*** Redis 令牌桶 限流*   这个等同于配置文件中的 redis-rate-limiter.replenishRate，redis-rate-limiter.burstCapacity*   同时存在时，加载的是配置文件中的配置* @return RedisRateLimiter*/@Bean RedisRateLimiter redisRateLimiter() {return new RedisRateLimiter(1, 1);}
}

6黑白名单

/*** @描述 禁用ip*/
public class BlackIpFilter implements GlobalFilter, Ordered {@Overridepublic int getOrder() {return 0;}@Overridepublic Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {ServerHttpRequest request = exchange.getRequest();String remoteIp = GatewayUtil.getRemoteIp(request);//查询 ip接口-缓存等实现if (true) {//返回禁用提示码exchange.getResponse().setStatusCode(HttpStatus.FORBIDDEN);return exchange.getResponse().setComplete();}return chain.filter(exchange);}
}

7 权限或token/续时/传递用户信息/串行/

package com.order.filter;import cn.hutool.core.collection.CollectionUtil;
import cn.hutool.core.lang.UUID;
import cn.hutool.core.util.ObjectUtil;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.order.entity.MyUser;
import com.order.utils.GatewayUtil;
import org.apache.commons.lang.StringUtils;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.core.Ordered;
import org.springframework.core.io.buffer.DataBuffer;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.stereotype.Component;
import org.springframework.util.MultiValueMap;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;import java.net.URI;
import java.nio.charset.StandardCharsets;
import java.util.*;/*** @创建人 赵伟* @创建时间 2024/3/20* @描述 禁用ip*/
@Component //需要将实现设置为Spring的组件
public class BlackIpFilter implements GlobalFilter, Ordered {/*** 顺序执行* @return*/@Overridepublic int getOrder() {return 0;}@Overridepublic Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {ServerHttpRequest request = exchange.getRequest();ServerHttpResponse response = exchange.getResponse();//1 ip黑名单String remoteIp = GatewayUtil.getRemoteIp(request);//查询 ip接口-缓存等实现if (false) {//返回禁用提示码return loseToken(exchange,response);//  return exchange.getResponse().setComplete();}//2 OPTIONS 不允许if (request.getMethod().equals(RequestMethod.OPTIONS.name())) {//返回禁用提示码exchange.getResponse().setStatusCode(HttpStatus.METHOD_NOT_ALLOWED);return exchange.getResponse().setComplete();}//4 忽略的urlString pass = "/aaa/getToken|/aaa/updatePwd";String uri = request.getURI().toString();if (isPass(pass, uri)) {return chain.filter(exchange);}//5 校验tokenList<String> tokenList = request.getHeaders().get("token");if (CollectionUtil.isEmpty(tokenList)) {return loseToken(exchange,response);}//6 根据token 获取redis用户信息判断是否失效，//注意多端系统生成token规则String token = tokenList.get(0);//自己写逻辑MyUser user = queryCacheByToken(token);if (ObjectUtil.isNull(user)) {return loseToken(exchange,response);}//7 已经获取到用户了,判断用户状态，是够禁用/用户密码强制多少天修改。 登录接口也要实现，boolean forbidden = false;//禁用if (forbidden) {return loseToken(exchange,response);}MultiValueMap<String, String> queryParams = exchange.getRequest().getQueryParams();//put是覆盖//  queryParams.put("userId", Collections.singletonList("123"));// add则不会覆盖，而是继续添加//   queryParams.add("userId","123");//3 设置请求头加串行idServerHttpRequest.Builder mutate = request.mutate();//不存在新增，存在即修改mutate.header("serialId", UUID.randomUUID().toString());//8 赋值用户信息 可用jwt加密 子服务 通过拦截器 在解析，放到ThreadLocal//请求头中文乱码//  mutate.header("userInfo", String.valueOf(user));String s = Base64.getEncoder().encodeToString(String.valueOf(user).getBytes());mutate.header("userInfo", s );ServerHttpRequest build = mutate.build();exchange.mutate().request(build).build();//9 token续时//刷新token失效时间 是否每次请求都要续时，还是先获取判断小于一定时间在续时//  redisTemplate.setExpire(token, 60 * 60 * 24);return chain.filter(exchange);}/*** 假的获取缓存用户信息* @param token* @return*/private MyUser queryCacheByToken(String token) {MyUser myUser = new MyUser();myUser.setUserId("123");myUser.setUserName("小明");myUser.setUpdatePasswordTime(new Date());return myUser;}/*** 失效token* @param exchange* @param response1* @return*/private Mono<Void> loseToken(ServerWebExchange exchange,ServerHttpResponse response1) {// 设置响应的Content-Type头并指定编码为UTF-8ServerHttpResponse response = exchange.getResponse();response.setStatusCode(HttpStatus.OK);response.getHeaders().add("Content-Type","application/json;charset=UTF-8");JSONObject responseBody = new JSONObject();responseBody.put("result", Boolean.FALSE);responseBody.put("msg", "您当前登录状态已失效，请重新登录");responseBody.put("status", 400);responseBody.put("isSuccess",  Boolean.FALSE);String s = JSON.toJSONString(responseBody);byte[] bytes = new String(s.getBytes(), StandardCharsets.UTF_8).getBytes(StandardCharsets.UTF_8);DataBuffer buffer = exchange.getResponse().bufferFactory().wrap(bytes);return  exchange.getResponse().writeWith(Flux.just(buffer));/*JSONObject jsonObject = new JSONObject();jsonObject.put("code","401");jsonObject.put("message","非法请求");byte[] datas = JSON.toJSONString(jsonObject).getBytes(StandardCharsets.UTF_8);DataBuffer buffer = response.bufferFactory().wrap(datas);response.setStatusCode(HttpStatus.UNAUTHORIZED);response.getHeaders().add("Content-Type", "application/json;charset=UTF-8");return response.writeWith(Mono.just(buffer));*/}/*** 是否放行的url* @param passString* @param requestURI* @return*/public static boolean isPass(String passString, String requestURI) {if (StringUtils.isNotBlank(passString)) {String[] split1 = passString.split("\\|");for (int i = 0; i < split1.length; i++) {String s = split1[i];if (!StringUtils.isBlank(s) && StringUtils.containsIgnoreCase(requestURI, s)) {return true;}}}return false;}}