详解SpringCloud Gateway 2020.0.2最新版

   <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
            <version>2.4.4</version>
        </dependency>
				<dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-gateway</artifactId>
          	<version>3.0.2</version>
        </dependency>

server:
  port: 9527
spring:
  application:
    name: cloud-gateway
  # 以下是gateway的配置
  cloud:
    gateway:
      routes:
        - id: gateway_route_1
          uri: https://www.baidu.com/s
          predicates:
            - Path=/s/**

package org.example.springcloud.config;

import org.springframework.cloud.gateway.route.RouteLocator;
import org.springframework.cloud.gateway.route.builder.RouteLocatorBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

/**
 * @Auth: guohui.wang
 * @Date: 2021-04-07 11:07
 * @desc:
 */
@Configuration
public class GatewayConfig {
    /**
     * <p>将 "ip:${server.port}+${route.path}" 转发到 "${route.url}"</p>
     * <p>例 "120.0.0.1:9527/s" 转发到 "https://www.baidu.com/s"</p><br>
     * <p>可以尝试访问以下链接获取配置效果</p>
     * <li>"http://localhost:9527/s"</li>
     * <li>"http://localhost:9527/s?wd=spring"</li>
     * <br>
     * <div>
     * <b>routes().route(参数1，参数2).route(参数1，参数2)……</b>
     * <li>参数1：id，一个可以随便取得名字，标识此路由规则</li>
     * <li>参数2：具体的路由规则内容</li>
     *
     * <b>路由规则：</b>
     * <li>path: 网关服务地址之后的内容（比如上面的"/s")</li>
     * <li>uri: 符合path之后需要转发到的位置</li>
     * </div>
     *
     * @param builder
     * @return
     */
    @Bean
    public RouteLocator routes(RouteLocatorBuilder builder) {
        return builder
                .routes()
                .route("gateway_route_1",
                        r -> r.path("/s")
                                .uri("https://www.baidu.com/s")
                )
                .build();
    }
}

package org.example.springcloud;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;

@SpringBootApplication
@EnableEurekaClient
public class GatewayMain9527 {
    public static void main(String[] args) {
        SpringApplication.run(GatewayMain9527.class, args);
    }
}

<dependencyManagement>
        <dependencies>
            <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-dependencies -->
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>2.4.4</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>

            <!-- https://mvnrepository.com/artifact/org.springframework.cloud/spring-cloud-dependencies -->
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>2020.0.2</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

 <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
        </dependency>
    </dependencies>

package org.example.springcloud.eureka;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
@EnableEurekaServer
public class EurekaApplication {
    public static void main(String[] args) {
        SpringApplication.run(EurekaApplication.class, args);
    }
}

server:
  port: 9001
eureka:
  instance:
    hostname: localhost
  client:
    # 不向注册中心注册自己
    register-with-eureka: false
    # 表示自己端就是注册中心，不需要检索服务
    fetch-registry: false
    service-url:
      # 设置与eureka server交互地址查询服务和注册服务都需要依赖这个地址
      defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka/

<dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>
    </dependencies>

package org.example.springcloud.provider;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;

@SpringBootApplication
@EnableEurekaClient
public class ProviderApplication {
    public static void main(String[] args) {
        SpringApplication.run(ProviderApplication.class, args);
    }
}

package org.example.springcloud.provider.controller;

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RequestMapping("/test")
@RestController
public class TestController {
    @GetMapping("/lb")
    public String lb() {
        return "访问成功";
    }
}

server:
  port: 9003
spring:
  application:
    name: cloud-provider
#eureka相关配置
eureka:
  instance:
    instance-id: cloud-provider-01
  client:
    service-url:
      defaultZone: http://127.0.0.1:9001/eureka
    register-with-eureka: true
    fetch-registry: true

 <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-gateway</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>
    </dependencies>

package org.example.springcloud.gateway;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;

@SpringBootApplication
@EnableEurekaClient
public class GatewayApplication {
    public static void main(String[] args) {
        SpringApplication.run(GatewayApplication.class, args);
    }
}

server:
  port: 9002
spring:
  application:
    name: cloud-gateway
  cloud:
    gateway:
      discovery:
        locator:
          #开启从注册中心动态创建路由功能，利用微服务名进行路由
          enabled: true
      routes:
        - id: payment_routh2
          # lb:// + ${目标服务的spring.application.name的值}
          uri: lb://cloud-provider
          # 映射的路径 访问符合Path值的路径，转发到响应的uri对应服务下Path
          predicates:
            - Path=/test/lb/**
#eureka相关配置
eureka:
  instance:
    instance-id: cloud-gateway-01
  client:
    service-url:
      defaultZone: http://127.0.0.1:9001/eureka
    register-with-eureka: true
    fetch-registry: true

package org.example.springcloud.gateway.filter;

import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.core.Ordered;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.stereotype.Component;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;

@Component
public class MyLogGatewayFilter implements GlobalFilter, Ordered {
    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        // 不用log.info了，为了省点事，别较真
        System.out.println("进入到了我们的自定义日志过滤器");
        // request、response啥的都能拿到，要干啥自己看着办吧，获取在下两行，
        // 你是要判断参数啊还是判断token啊还是咋地那你自己定义去吧。
        // ServerHttpRequest request = exchange.getRequest();
        // ServerHttpResponse response = exchange.getResponse();

        // 返回chain.filter(exchange); 表示此过滤器通过，将请求继续传递下去
        // 交由下面的过滤器继续处理
        // 如果是 return null; 则表示被过滤掉了，没通过。
        return chain.filter(exchange);
    }

    @Override
    public int getOrder() {
        // 加载过滤器的顺序，数值越小优先级越高。
        // Integer.MIN_VALUE 到 Integer.MAX_VALUE
        return 0;
    }
}