一、網(wǎng)關(guān)服務(wù)的搭建

Spring Cloud Gateway 和 nacos 不一樣，我們必須自己搭建工程，首先創(chuàng)建一個新的 Spring Boot 項(xiàng)目

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>mall-parent</artifactId>
        <groupId>com.company</groupId>
        <version>1.0.0</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>mall-gateway</artifactId>

    <properties>
        <maven.compiler.source>11</maven.compiler.source>
        <maven.compiler.target>11</maven.compiler.target>
    </properties>
    <dependencies>
        <!-- 網(wǎng)關(guān) -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-gateway</artifactId>
        </dependency>
        <!--nacos discovery-->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>
        <!--負(fù)載均衡-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-loadbalancer</artifactId>
        </dependency>
    </dependencies>
    <build>
        <finalName>${project.artifactId}</finalName>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

在配置文件 application.yaml 中編寫路由規(guī)則

server:
  port: 8080
spring:
  application:
    name: gateway
  cloud:
    nacos:
      server-addr: 192.168.150.101:8848
    gateway:
      routes:
        - id: product                     # 路由規(guī)則id，自定義，唯一
          uri: lb://product-service       # 路由的目標(biāo)服務(wù)，lb代表負(fù)載均衡，會從注冊中心拉取服務(wù)列表
          predicates:                     # 路由斷言，判斷當(dāng)前請求是否符合當(dāng)前規(guī)則，符合則路由到目標(biāo)服務(wù)
            - Path=/product/**,/search/** # 這里是以請求路徑作為判斷規(guī)則
        - id: cart
          uri: lb://cart-service
          predicates:
            - Path=/carts/**
          filters:                        # 在這里可以配置過濾器
            - AddRequestHeader=key, value # 逗號之前是HTTP請求頭的key，逗號之后是value
        - id: user
          uri: lb://user-service
          predicates:
            - Path=/users/**,/addresses/**

最后，啟動項(xiàng)目即可

二、GatewayFilter 路由過濾器

@Component
public class PrintAnyGatewayFilterFactory extends AbstractGatewayFilterFactory<Object> {
    @Override
    public GatewayFilter apply(Object config) {
        return new GatewayFilter() {
            @Override
            public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
                // 獲取請求
                ServerHttpRequest request = exchange.getRequest();
                // 編寫過濾器邏輯
                System.out.println("過濾器執(zhí)行了");
                // 放行
                return chain.filter(exchange);
            }
        };
    }
}

注意：該類的名稱一定要以 GatewayFilterFactory 為后綴

三、GlobalFilter 全局過濾器

自定義GlobalFilter則簡單很多，直接實(shí)現(xiàn)GlobalFilter即可，而且也無法設(shè)置動態(tài)參數(shù)

@Component
public class PrintAnyGlobalFilter implements GlobalFilter, Ordered {
    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        // 編寫過濾器邏輯
        System.out.println("未登錄，無法訪問");
        // 放行
        // return chain.filter(exchange);

        // 攔截
        ServerHttpResponse response = exchange.getResponse();
        response.setRawStatusCode(401);
        return response.setComplete();
    }

    @Override
    public int getOrder() {
        // 過濾器執(zhí)行順序，值越小，優(yōu)先級越高
        return 0;
    }
}