1、添加依赖

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-gateway</artifactId>
        </dependency>

• 完整版的pom.xml文件

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.2.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.shenmazong</groupId>
    <artifactId>cloud-nacos-gateway</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>cloud-nacos-gateway</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
        <!-- SpringCloud的版本 -->
        <spring-cloud.version>Hoxton.SR2</spring-cloud.version>
    </properties>
    <dependencies>
        <!-- gateway -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-gateway</artifactId>
        </dependency>

        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
            <version>2.2.2.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
            <version>2.2.2.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>
    <!-- SpringCloud的依赖 -->
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

2、配置文件

• 本地配置文件

spring.application.name=cloud-nacos-gateway
server.port=9099


spring.cloud.nacos.discovery.server-addr=127.0.0.1:8848


spring.cloud.nacos.config.server-addr=127.0.0.1:8848
spring.cloud.nacos.config.file-extension=properties

• nacos上的配置文件

#设置路由id
spring.cloud.gateway.routes[0].id=cloud-nacos-consumer
spring.cloud.gateway.routes[0].uri=lb://cloud-nacos-consumer
spring.cloud.gateway.routes[0].predicates[0]=Path=/user/**
spring.cloud.gateway.routes[0].filters=StripPrefix=1

3、启动类

package com.shenmazong.cloudnacosgateway;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;

@SpringBootApplication
@EnableDiscoveryClient
public class CloudNacosGatewayApplication {

    public static void main(String[] args) {
        SpringApplication.run(CloudNacosGatewayApplication.class, args);
    }
}

4、过滤器

package com.shenmazong.cloudnacosgateway.filter;

import org.apache.commons.lang3.StringUtils;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.Ordered;
import org.springframework.core.io.buffer.DataBuffer;
import org.springframework.http.HttpHeaders;
import org.springframework.http.MediaType;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;

import java.awt.*;
import java.nio.charset.StandardCharsets;

/**
 * @author 军哥
 * @version 1.0
 * @description: gateway过滤器
 * @date 2021/8/19 15:51
 */

@Configuration
public class GatewayFilter implements GlobalFilter, Ordered {

    @Override
    public int getOrder() {
        return 0;
    }

    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        // 获取Request、Response对象
        ServerHttpRequest request = exchange.getRequest();
        ServerHttpResponse response = exchange.getResponse();

        // 解决中文乱码问题
        HttpHeaders headers = response.getHeaders();
        headers.setContentType(MediaType.APPLICATION_JSON);

        //
        String requestUrl = exchange.getRequest().getURI().getRawPath();
        System.out.println(requestUrl);
        System.out.println(request.getURI());

        // 检查head中的token
        String token = request.getHeaders().getFirst("token");
        if(StringUtils.isEmpty(token)) {
            String msg = "{code:-1, message:'用户没有登录'}";
            DataBuffer dataBuffer = response.bufferFactory().wrap(msg.getBytes(StandardCharsets.UTF_8));
            return response.writeWith(Mono.just(dataBuffer));
        }

        // 放行
        return chain.filter(exchange);
    }
}

5、测试

测试运行即可。

6、GateWay的跨域

方法一：配置类

写个配置类CorsConfig (如果不行，可以不写此类，和springcloud的版本有关)

package net.youqu.micro.service.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.cors.CorsConfiguration;
import org.springframework.web.cors.reactive.CorsWebFilter;
import org.springframework.web.cors.reactive.UrlBasedCorsConfigurationSource;
import org.springframework.web.util.pattern.PathPatternParser;

/**
 * description:
 * java项目www.fhadmin.org
 */
@Configuration
public class CorsConfig {
    @Bean
    public CorsWebFilter corsFilter() {
        CorsConfiguration config = new CorsConfiguration();
        config.addAllowedMethod("*");
        config.addAllowedOrigin("*");
        config.addAllowedHeader("*");

        UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource(new PathPatternParser());
        source.registerCorsConfiguration("/**", config);

        return new CorsWebFilter(source);
    }
}

方法二：配置文件

• 配置 application.properties 方式

#--------gateway配置--------
#跨域配置
spring.cloud.gateway.globalcors.corsConfigurations.[/**].allowedOrigins=*
spring.cloud.gateway.globalcors.corsConfigurations.[/**].allowedHeaders=*
spring.cloud.gateway.globalcors.corsConfigurations.[/**].allowedMethods=*
spring.cloud.gateway.globalcors.corsConfigurations.[/**].allowCredentials=true

• yaml 方式

spring:
  cloud:
    gateway:
      globalcors:
        corsConfigurations:
          '[/**]':
            allowCredentials: true
            allowedHeaders: '*'
            allowedMethods: '*'
            allowedOrigins: '*'