Spring Cloud Gateway 聚合 Swagger

Gateway 聚合 swagger 雖然網上已經有了很多處理方法，但是參差不齊有很多坑，還是記錄一下。

1. 環境說明

• 網關依賴 GateWay 2.2.5.RELEASE
• 注冊中心依賴 nacos-discovery 2.2.1.RELEASE
• Spring Boot v2.3.0.RELEASE

2. 一般服務配置Swagger

2.1 引入swagger依賴

<!--swagger-->
<dependency>
    <groupId>com.spring4all</groupId>
    <artifactId>swagger-spring-boot-starter</artifactId>
    <version>1.9.1.RELEASE</version>
</dependency>

2.2 啟動類加入@EnableSwagger2Doc注解

@EnableSwagger2Doc
@SpringBootApplication
public class SystemApplication {
    public static void main(String[] args) {
        SpringApplication.run(SystemApplication.class, args);
    }
}

完成以上倆個步驟，一般服務就可以使用swagger了。

3. Gateway 網關配置

3.1 引入swagger依賴

<!--swagger-->
<dependency>
    <groupId>com.spring4all</groupId>
    <artifactId>swagger-spring-boot-starter</artifactId>
    <version>1.9.1.RELEASE</version>
</dependency>

3.2 添加SwaggerHandler、SwaggerResourceConfig兩個類

SwaggerHandler代碼如下：

package com.gct.gateway.swagger;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import reactor.core.publisher.Mono;
import springfox.documentation.swagger.web.*;

import java.util.Optional;

/**
 * @author: NewMeanning
 * @create: 2020-12-24 16:57
 **/
@RestController
public class SwaggerHandler {

    @Autowired(required = false)
    private SecurityConfiguration securityConfiguration;

    @Autowired(required = false)
    private UiConfiguration uiConfiguration;

    private final SwaggerResourcesProvider swaggerResources;

    @Autowired
    public SwaggerHandler(SwaggerResourcesProvider swaggerResources) {
        this.swaggerResources = swaggerResources;
    }


    @GetMapping("/swagger-resources/configuration/security")
    public Mono<ResponseEntity<SecurityConfiguration>> securityConfiguration() {
        return Mono.just(new ResponseEntity<>(
                Optional.ofNullable(securityConfiguration).orElse(SecurityConfigurationBuilder.builder().build()), HttpStatus.OK));
    }

    @GetMapping("/swagger-resources/configuration/ui")
    public Mono<ResponseEntity<UiConfiguration>> uiConfiguration() {
        return Mono.just(new ResponseEntity<>(
                Optional.ofNullable(uiConfiguration).orElse(UiConfigurationBuilder.builder().build()), HttpStatus.OK));
    }

    @GetMapping("/swagger-resources")
    public Mono<ResponseEntity> swaggerResources() {
        return Mono.just((new ResponseEntity<>(swaggerResources.get(), HttpStatus.OK)));
    }

    @GetMapping("/")
    public Mono<ResponseEntity> swaggerResourcesN() {
        return Mono.just((new ResponseEntity<>(swaggerResources.get(), HttpStatus.OK)));
    }

    @GetMapping("/csrf")
    public Mono<ResponseEntity> swaggerResourcesCsrf() {
        return Mono.just((new ResponseEntity<>(swaggerResources.get(), HttpStatus.OK)));
    }
}

SwaggerResourceConfig代碼如下：

package com.gct.gateway.swagger;

import lombok.AllArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.cloud.gateway.config.GatewayProperties;
import org.springframework.cloud.gateway.route.RouteLocator;
import org.springframework.cloud.gateway.support.NameUtils;
import org.springframework.context.annotation.Primary;
import org.springframework.stereotype.Component;
import springfox.documentation.swagger.web.SwaggerResource;
import springfox.documentation.swagger.web.SwaggerResourcesProvider;

import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

/**
 * @author: NewMeanning
 * @create: 2020-12-24 16:56
 **/
@Slf4j
@Component
@Primary
@AllArgsConstructor
public class SwaggerResourceConfig implements SwaggerResourcesProvider {

    /**
     * swagger2默認的url后綴
     */
    private static final String SWAGGER2URL = "/v2/api-docs";

    /**
     * 網關路由
     */
    private final RouteLocator routeLocator;

    /**
     * 網關應用名稱
     */
    @Value("${spring.application.name}")
    private String self;

    @Autowired
    public SwaggerResourceConfig(RouteLocator routeLocator) {
        this.routeLocator = routeLocator;
    }

    @Override
    public List<SwaggerResource> get() {
        List<SwaggerResource> resources = new ArrayList<>();
        List<String> routeHosts = new ArrayList<>();
        // 由於我的網關采用的是負載均衡的方式，因此我需要拿到所有應用的serviceId
        // 獲取所有可用的host：serviceId
        routeLocator.getRoutes().filter(route -> route.getUri().getHost() != null)
                .filter(route -> !self.equals(route.getUri().getHost()))
                .subscribe(route -> routeHosts.add(route.getUri().getHost()));

        // 記錄已經添加過的server，存在同一個應用注冊了多個服務在nacos上
        Set<String> dealed = new HashSet<>();
        routeHosts.forEach(instance -> {
            // 拼接url，樣式為/serviceId/v2/api-info，當網關調用這個接口時，會自動通過負載均衡尋找對應的主機
            String url = "/" + instance + SWAGGER2URL;
            if (!dealed.contains(url)) {
                dealed.add(url);
                SwaggerResource swaggerResource = new SwaggerResource();
                swaggerResource.setUrl(url);
                swaggerResource.setName(instance);
                resources.add(swaggerResource);
            }
        });
        return resources;
    }
}

3.3 application配置

只需要指定spring.application.name即可，名稱隨意；另外無需配置router，配置如下：

# 端口號
server:
  port: 88

spring:
  cloud:
    nacos:
      discovery:
        ## 指定nacos server地址
        server-addr: localhost:8848
    gateway:
      discovery:
        locator:
          enabled: true  # 啟用網關
  ## 本服務名稱
  application:
    name: gateway