断言：

Path
根据请求路径的正则匹配
spring:
application:
name: gateway-server
cloud:
gateway:
routes:
- id: aaa
uri: http://localhost:8001
predicates:
- Path=/product/** #http://网关ip:网关端口/product/add 自动匹配到 http://localhost:8001
- id: bbb
uri: http://localhost:8002
predicates:
- Path=/order/**
Query
根据请求携带的参数匹配路由
spring:
application:
name: gateway-server
cloud:
gateway:
routes:
- id: aaa
uri: http://localhost:8001
predicates:
# 如果请求url中带有name参数 ---> http://localhost:8001
- Query=name
- id: bbb
uri: http://localhost:8002
predicates:
#如果请求url中带有pwd参数 ---> http://localhost:8002
- Query=pwd
Header
根据Header中携带的参数匹配
spring:
application:
name: gateway-server
cloud:
gateway:
routes:
- id: aaa
uri: http://localhost:8001
predicates:
- Header=token
- id: bbb
uri: http://localhost:8002
predicates:
- Header=aa,haha
==========================
过滤器：
spring:
application:
name: gateway-server
cloud:
gateway:
routes:
- id: aaa
uri: http://localhost:8001
predicates:
- Path=/red/aaa/product/**
filters:
- AddRequestHeader=token,wahahaawahaha
- AddRequestParameter=username, ergou
- SetStatus=404
# - RewritePath=/red(?<segment>/?.*), $\{segment}
- StripPrefix=2
代码中通过controller类进行参数的获取

-------
自定义过滤器
创建网关过滤器 - 实现GatewayFilter
public class MyFilter01 implements GatewayFilter, Ordered {
@Override
public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
ServerHttpRequest request = exchange.getRequest();
ServerHttpResponse response = exchange.getResponse();
System.out.println("---------------⾃定义过滤器");
return chain.filter(exchange);
}
@Override
public int getOrder() { //Ordered对过滤器进行排序
return 0;
}
}
配置过滤器 （替代配置文件中的网关配置）
@Configuration
public class GatewayConfig {
@Bean
public RouteLocator routeLocator(RouteLocatorBuilder builder){
System.out.println("-----------------------init");
RouteLocator routeLocator = builder.routes().route( r-> r.path("/product/**") // predicates
.filters(f->f.filters( new MyFilter01() )) // filters
.uri("http://localhost:8001") //uri
).build();
return routeLocator;
}
}
第二种创建网关过滤器方法
要求：类名必须同内置的过滤一致，即GatewayFilterFactory结尾
继承AbstractNameValueGatewayFilerFactory
自动会被加载到内置过滤器中管理


全局过滤器，不仅仅针对某个路由（服务中）
Gateway提供了内置的全局过滤器默认生效，会拦截所有到达网关的请求
根据业务自定义全局过滤器对多有网关请求进行拦截处理

Gateway动态路由配置
即将Gateway模块也注册到注册中心上，而Gateway本身的配置中不在写死路由ip



