SpringCloud教程第十弹第二代网关springcloudgateway

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1.1、路由route

路由是网关最基础的部分。路由信息由一个ID、一个目的url、一组断言工厂和一组Filter组成。如果路由断言为真&＃xff0c;则说明请求的url和配置的路由匹配。

1.2、断言predicate

Java8中的断言函数。spring cloud gateway中的断言函数输入类型是spring5.0框架中的ServerWebExchange。spring cloud gateway中的断言函数允许开发者去定义来自于Http Request中的任何信息&＃xff0c;比如请求头和参数等。

1.3、过滤器filter

一个标准的spring webfilter。spring cloud gateway中的filter分为两种类型&＃xff1a;分别是gateway filter和global filter。

1. gateway客户端向gateway发起请求
2. 请求首先被HttpWebHandlerAdapter进行提取组装成网关的上下文
3. 然后网关上下文会传递到DispatcherHandler
4. DispatcherHandler是所有请求的分发处理器&＃xff0c;主要负责分发请求对应的处理器。比如将请求分发到对应的RoutePredicate-HandlerMapping(路由断言处理映射器)
5. 路由断言处理映射器主要用于路由的查找&＃xff0c;以及找到路由后返回对应的FilterWebHandler
6. FilterWebHandler主要负责组装Filter链表并调用Filter执行一系列的Filter处理&＃xff0c;然后把请求转到后端对应的代理服务处理
7. 处理完毕后&＃xff0c;将response返回给gateway客户端

注意&＃xff1a;

• 过滤器分为Pre和Post&＃xff0c;分别在转发请求之前处理和接收到代理服务返回的结果之后处理
• 在配置路由时&＃xff0c;如果不指定端口&＃xff0c;则http默认端口为80&＃xff0c;https默认端口为443
• gateway目前只支持netty容器

2.1、概述

路由断言&＃xff1a;

• Path路由断言工厂
• Before路由断言工厂
• Between断言工厂
• COOKIE路由断言工厂
• Header路由断言工厂
• Host路由断言工厂
• Method路由断言工厂
• Query路由断言工厂
• RemoteAddr路由断言工厂

路由过滤&＃xff1a;

spring cloud gateway内置了很多的路由过滤工厂&＃xff0c;也可以根据需要自定义路由过滤工厂

路由过滤器允许以某种方式修改request或response

2.2、基于yml配置

spring:cloud:gateway:routes:- id: findAlluri: http://localhost:8130predicates:- Path&＃61;/findAll- id: findOneuri: http://localhost:8130predicates:- Path&＃61;/findOne

2.3、基于JavaConfig配置

import org.springframework.cloud.gateway.route.Route;
import org.springframework.cloud.gateway.route.RouteLocator;
import org.springframework.cloud.gateway.route.builder.GatewayFilterSpec;
import org.springframework.cloud.gateway.route.builder.PredicateSpec;
import org.springframework.cloud.gateway.route.builder.RouteLocatorBuilder;
import org.springframework.cloud.gateway.route.builder.UriSpec;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;import java.time.ZoneId;
import java.time.ZonedDateTime;
import java.util.function.Function;&＃64;Configuration
public class GatewayRouteConfig {&＃64;Beanpublic RouteLocator customRouteLocator(RouteLocatorBuilder builder){ZonedDateTime dateTime &＃61; ZonedDateTime.of(2020, 10, 17, 22, 40, 0, 0, ZoneId.systemDefault());return builder.routes()//普通path断言.route(r->r.path("/getStudentName").filters(new Function() {&＃64;Overridepublic UriSpec apply(GatewayFilterSpec gatewayFilterSpec) {return gatewayFilterSpec.addRequestHeader("stuName", "bobo");}}).uri("http://localhost:8130").id("getStudentName"))//after断言&＃43;path断言.route(new Function() {&＃64;Overridepublic Route.AsyncBuilder apply(PredicateSpec predicateSpec) {predicateSpec.path("/listStudent").and().after(dateTime);Route.AsyncBuilder asyncBuilder &＃61; predicateSpec.uri("http://localhost:8130");asyncBuilder.id("listStudent");return asyncBuilder;}})//path通配符断言.route(r->r.path("/student/**").uri("http://localhost:8130").id("student")).build();}
}

3、gateway集成eureka服务注册中心

3.1、pom.xml

注意springboot和springcloud的版本&＃xff0c;如果是其它版本&＃xff0c;启动项目的时候可能会报错

org.springframework.bootspring-boot-starter-parent2.2.6.RELEASE 1.8Hoxton.SR4org.springframework.cloudspring-cloud-starter-gatewayorg.springframework.bootspring-boot-starter-weborg.springframework.bootspring-boot-starter-actuatororg.springframework.cloudspring-cloud-starter-netflix-eureka-clientorg.springframeworkspring-expressionorg.springframework.cloudspring-cloud-dependencies${spring-cloud.version}pomimport

3.2、application.yml关键配置

spring:cloud:gateway:discovery:locator:#与服务注册中心集成enabled: true#因为eureka的serviceId默认是大写&＃xff0c;设为true之后&＃xff0c;在gateway中可以用小写的serviceId进行路由转发lowerCaseServiceId: true
eureka:client:service-url:defaultZone: http://localhost:8000/eureka/register-with-eureka: true

3.3、自动路由匹配

gateway与eureka集成后&＃xff0c;即使不配置路由&＃xff0c;也会进行自动路由匹配

比如在eureka上注册了一个服务提供者service-a&＃xff0c;service-a的上下文是/service-a&＃xff0c;端口是8080&＃xff0c;且暴露了一个接口&＃xff0c;路径为/student/getName

gateway的端口是9000&＃xff0c;则访问http://localhost:9000/service-a/service-a/student/getName&＃xff0c;可自动匹配到service-a

通过gateway的日志可以看到&＃xff0c;自动路由的信息如下&＃xff1a;

Route{id&＃61;&＃39;ReactiveCompositeDiscoveryClient_SERVICE-A&＃39;, uri&＃61;lb://SERVICE-A, order&＃61;0, predicate&＃61;Paths: [/service-a/**], \
其中&＃xff0c;lb表示该uri从注册中心查找

4.1、概述

spring cloud gateway的Filter实际上分两种&＃xff1a;

• GatewayFilter&＃xff1a;应用到单个路由或一组路由&＃xff0c;前面讲的路由过滤器工厂就是GatewayFilter
• GlobalFilter&＃xff1a;应用到所有的路由

4.2、自定义GatewayFilter

import org.springframework.cloud.gateway.filter.GatewayFilter;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.http.HttpHeaders;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;import java.util.List;
import java.util.Map;
import java.util.Set;public class PrintHeaderGatewayFilter implements GatewayFilter {&＃64;Overridepublic Mono filter(ServerWebExchange exchange, GatewayFilterChain chain) {System.out.println("执行PrintHeaderFilter");ServerHttpRequest request &＃61; exchange.getRequest();HttpHeaders headers &＃61; request.getHeaders();Set>> entries &＃61; headers.entrySet();for (Map.Entry> entry : entries) {System.out.println(entry.getKey()&＃43;"----"&＃43;entry.getValue());}return chain.filter(exchange);}
}


4.3、自定义GlobalFilter

import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.http.HttpStatus;
import org.springframework.stereotype.Component;
import org.springframework.util.CollectionUtils;
import org.springframework.util.MultiValueMap;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;import java.util.List;&＃64;Component
public class TokenGlobalFilter implements GlobalFilter {&＃64;Overridepublic Mono filter(ServerWebExchange exchange, GatewayFilterChain chain) {MultiValueMap queryParams &＃61;exchange.getRequest().getQueryParams();List list &＃61; queryParams.get("token");if(CollectionUtils.isEmpty(list)){exchange.getResponse().setStatusCode(HttpStatus.UNAUTHORIZED);return exchange.getResponse().setComplete();}return chain.filter(exchange);}
}


4.4、自定义GatewayFilterFactory

import org.springframework.cloud.gateway.filter.GatewayFilter;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.factory.AbstractGatewayFilterFactory;
import org.springframework.stereotype.Component;
import org.springframework.util.MultiValueMap;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;import java.util.List;&＃64;Component
public class PrintParamGatewayFilterFactory extends AbstractGatewayFilterFactory{&＃64;Overridepublic GatewayFilter apply(Config config) {return new GatewayFilter() {&＃64;Overridepublic Mono filter(ServerWebExchange exchange, GatewayFilterChain chain) {String url &＃61; exchange.getRequest().getURI().getPath();if (!config.getIgnoreUrl().contains(url)){MultiValueMap queryParams &＃61; exchange.getRequest().getQueryParams();for (String s : queryParams.keySet()) {System.out.println(s&＃43;"----"&＃43;queryParams.get(s));}}return chain.filter(exchange);}};}public PrintParamGatewayFilterFactory(){super(Config.class);}/*** 自定义config类&＃xff0c;能读取到yml中的配置*/public static class Config{private List ignoreUrl;public List getIgnoreUrl() {return ignoreUrl;}public void setIgnoreUrl(List ignoreUrl) {this.ignoreUrl &＃61; ignoreUrl;}}}


spring:cloud:gateway:routes:- id: methodGetorder: -100uri: http://localhost:8130predicates:- Method&＃61;GETfilters:- name: PrintParam # 如果类名为 ???GatewayFilterFactory&＃xff0c;则过滤器名为???args:ignoreUrl:- /findAll- /findOne