Spring Cloud Gateway②聚合Swagger

偏执的太偏执、 2023-09-28 14:12 43阅读 0赞

#### 目录 ####

*  背景
 *  本文开发环境介绍
 *  搭建一个微服务
 *   *  pom.xml的依赖如下
     *  开启Swagger
     *  application.yml如下
     *  运行main函数启动微服务
     *  访问微服务Swagger
 *  Gateway入门
 *  Gateway配置
 *   *  \`pom.xml\`依赖
     *  转发配置示例
     *  实现SwaggerResourcesProvider接口
     *  重写Swagger的数据接口
     *  启动类
     *  Swagger访问测试
 *  总结

## 背景 ##

各个微服务都有自己的**Swagger**文档，当使用**Gateway**做为微服务统一入口时，如何对外统一暴露微服务的**Swagger**呢？这篇文章继续演示**Gateway**聚合各个微服务的**Swagger**的能力，以最小依赖为原则，不依赖注册中心，以便聚焦如何展示**Swagger**这部分的功能。

## 本文开发环境介绍 ##

<table> 
 <thead> 
  <tr> 
   <th align="left">开发依赖</th> 
   <th align="left">版本</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td align="left">Spring Boot</td> 
   <td align="left">2.7.0</td> 
  </tr> 
  <tr> 
   <td align="left">Spring Cloud</td> 
   <td align="left">2021.0.1</td> 
  </tr> 
  <tr> 
   <td align="left">Spring Cloud Alibaba</td> 
   <td align="left">2021.0.1.0</td> 
  </tr> 
 </tbody> 
</table>

## 搭建一个微服务 ##

微服务需要提供**Swagger**

### pom.xml的依赖如下 ###

<properties>
            <springfox-boot-starter.version>3.0.0</springfox-boot-starter.version>
        </properties>
    
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
    
            <dependency>
                <groupId>io.springfox</groupId>
                <artifactId>springfox-boot-starter</artifactId>
                <version>${springfox-boot-starter.version}</version>
            </dependency>
        </dependencies>

### 开启Swagger ###

import io.swagger.annotations.Api;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    import springfox.documentation.builders.ApiInfoBuilder;
    import springfox.documentation.builders.PathSelectors;
    import springfox.documentation.builders.RequestHandlerSelectors;
    import springfox.documentation.oas.annotations.EnableOpenApi;
    import springfox.documentation.service.ApiInfo;
    import springfox.documentation.service.Contact;
    import springfox.documentation.spi.DocumentationType;
    import springfox.documentation.spring.web.plugins.Docket;
    
    @Configuration
    @EnableOpenApi
    public class SwaggerAutoConfiguration {
        
    
        @Bean
        public Docket onlineDocApi() {
        
            return new Docket(DocumentationType.OAS_30)
                    .apiInfo(apiInfo("Controller接口", "接口文档", "1.0"))
                    .select()
                    .apis( RequestHandlerSelectors.withClassAnnotation(Api.class))
                    .paths(PathSelectors.any())
                    .build();
        }
    
        private ApiInfo apiInfo(String name, String description, String version) {
        
            return new ApiInfoBuilder()
                    .title(name)
                    .description(description)
                    .contact(new Contact("demo", null, null))
                    .version(version).build();
        }
    }

### application.yml如下 ###

server:
      port: 8082
    spring:
      mvc:
        pathmatch:
          matching-strategy: ant_path_matcher

### 运行main函数启动微服务 ###

import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    
    @SpringBootApplication
    public class SwaggerDemoApplication {
        
    
        public static void main(String[] args) {
        
            SpringApplication.run(SwaggerDemoApplication.class, args);
        }
    }

### 访问微服务Swagger ###

在浏览器输入`http://localhost:8082/swagger-ui/index.html`  
![在这里插入图片描述][5f841f2843554648bbd2c64a6bee36aa.png]  
说明这个微服务的**Swagger**已经正常开启了

## Gateway入门 ##

如果还不熟悉**Gateway**的可以参考上一篇写的[Gateway入门][Gateway]

## Gateway配置 ##

### `pom.xml`依赖 ###

<dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-gateway</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-webflux</artifactId>
            </dependency>
            <dependency>
                <groupId>io.springfox</groupId>
                <artifactId>springfox-boot-starter</artifactId>
                <version>${springfox-boot-starter.version}</version>
            </dependency>
        </dependencies>

### 转发配置示例 ###

`application.yml`配置如下

server:
      port: 8081
    spring:
      application:
        name: demo-gateway
      mvc:
        pathmatch:
          matching-strategy: ant_path_matcher
      cloud:
        gateway:
          #路由配置
          routes:
            - id: demoSwagger
              uri: http://localhost:8082
              predicates:
                - Path=/demo/**
              filters:
                - StripPrefix=1

### 实现SwaggerResourcesProvider接口 ###

import lombok.RequiredArgsConstructor;
    import lombok.extern.slf4j.Slf4j;
    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.List;
    
    @RequiredArgsConstructor
    @Slf4j
    @Component
    @Primary
    public class SwaggerProvider implements SwaggerResourcesProvider {
        
    
        /**swagger2默认的url后缀*/
        private static final String SWAGGER_URI = "/v2/api-docs";
    
        private final RouteLocator routeLocator;
        private final GatewayProperties gatewayProperties;
    
        @Override
        public List<SwaggerResource> get() {
        
            List<SwaggerResource> resources = new ArrayList<>();
            List<String> routes = new ArrayList<>();
            // 只抽取后缀为Swagger的路由信息
            routeLocator.getRoutes()
                    .filter(route -> route.getId().endsWith("Swagger"))
                    .subscribe(route -> routes.add(route.getId()));
    
            gatewayProperties.getRoutes().stream().filter(routeDefinition -> routes.contains(routeDefinition.getId())).forEach(route -> {
        
                route.getPredicates().stream()
                        .filter(predicateDefinition -> ("Path").equalsIgnoreCase(predicateDefinition.getName()))
                        .forEach(predicateDefinition -> resources.add(swaggerResource(route.getId(),
                                predicateDefinition.getArgs().get(NameUtils.GENERATED_NAME_PREFIX + "0")
                                        .replace("/**", SWAGGER_URI))));
            });
            return resources;
        }
    
        private SwaggerResource swaggerResource(String name, String location) {
        
            log.info("name:{},location:{}",name,location);
            SwaggerResource swaggerResource = new SwaggerResource();
            swaggerResource.setName(name);
            swaggerResource.setLocation(location);
            return swaggerResource;
        }
    }

### 重写Swagger的数据接口 ###

import lombok.RequiredArgsConstructor;
    import org.springframework.http.HttpStatus;
    import org.springframework.http.ResponseEntity;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    import springfox.documentation.swagger.web.*;
    
    import java.util.List;
    
    @RequiredArgsConstructor
    @RestController
    @RequestMapping("/swagger-resources")
    public class SwaggerResourceController {
        
    
        private final SwaggerProvider swaggerResourceProvider;
    
        @RequestMapping(value = "/configuration/security")
        public ResponseEntity<SecurityConfiguration> securityConfiguration() {
        
            return new ResponseEntity<>(SecurityConfigurationBuilder.builder().build(), HttpStatus.OK);
        }
    
        @RequestMapping(value = "/configuration/ui")
        public ResponseEntity<UiConfiguration> uiConfiguration() {
        
            return new ResponseEntity<>(UiConfigurationBuilder.builder().build(), HttpStatus.OK);
        }
    
        @RequestMapping
        public ResponseEntity<List<SwaggerResource>> swaggerResources() {
        
            return new ResponseEntity<>(swaggerResourceProvider.get(), HttpStatus.OK);
        }
    }

### 启动类 ###

import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import springfox.documentation.oas.annotations.EnableOpenApi;
    
    @EnableOpenApi
    @SpringBootApplication
    public class DemoGatewayApplication {
        
    
        public static void main(String[] args) {
        
            SpringApplication.run(DemoGatewayApplication.class, args);
        }
    }

### Swagger访问测试 ###

在浏览器输入`http://localhost:8081/swagger-ui`  
![在这里插入图片描述][a9ef80766d0e4713bf72f55dd06a4a62.png]

看到的**Swagger**与`8082`端口的微服务是一样的

## 总结 ##

我们在开发微服务的过程中，由于各种原因，会引入API网关，那么之前直接由微服务对外提供的**Swagger**文档，也同样希望可以通过API网关统一对外展示，本文通过最小依赖，使用极简的方式演示了**Gateway**如何聚合后端微服务的**Swagger**文档，希望可以帮助到大家少走一点弯路。

[5f841f2843554648bbd2c64a6bee36aa.png]: https://img-blog.csdnimg.cn/5f841f2843554648bbd2c64a6bee36aa.png
[Gateway]: https://blog.csdn.net/friendlytkyj/article/details/125660947
[a9ef80766d0e4713bf72f55dd06a4a62.png]: https://img-blog.csdnimg.cn/a9ef80766d0e4713bf72f55dd06a4a62.png