基于前两篇文章，进行整合

springcloud-gateway 聚合swagger3请求接口丢失appliactionName解决

springcloud-gateway聚合knife4j接口文档

为何要兼容？微服务开发者有的使用了swagger2版本，有的使用了swagger3版本，但暴露外部给前端使用的，均统一走网关处

兼容核心点：swagger3 返回缺少bathPath

网关配置

@Data
@ConfigurationProperties(prefix = MyGateWayProperties.PREFIX)
public class MyGateWayProperties {public static final String PREFIX = "gateway";/*** swagger3 服务列表*/private List swagger3Set;/*** 请求前缀*/private String apiPrefix;
}

请求文档的SwaggerResourcesProvider 进行调整，带上自定义网关请求前缀与 swagger文档后缀

@RestController
@RequestMapping("/swagger-resources")
public class SwaggerHandler {@Autowired(required = false)private SecurityConfiguration securityConfiguration;@Autowired(required = false)private UiConfiguration uiConfiguration;private final SwaggerResourcesProvider provider;@Autowiredpublic SwaggerHandler(SwaggerResourcesProvider provider) {this.provider = provider;}@GetMapping("/configuration/security")public Mono> securityConfiguration() {return Mono.just(new ResponseEntity<>(Optional.ofNullable(securityConfiguration).orElse(SecurityConfigurationBuilder.builder().build()),HttpStatus.OK));}@GetMapping("/configuration/ui")public Mono> uiConfiguration() {return Mono.just(new ResponseEntity<>(Optional.ofNullable(uiConfiguration).orElse(UiConfigurationBuilder.builder().build()), HttpStatus.OK));}@GetMappingpublic Mono>> swaggerResources() {return Mono.just((new ResponseEntity<>(provider.get(), HttpStatus.OK)));}
}

/*** @author lei* @create 2022-05-25 10:01* @desc 网关处获取所有服务swagger文档**/
@Slf4j
@Component
@Primary
public class SwaggerProvider implements SwaggerResourcesProvider {/*** swagger2默认的url后缀*/public static final String V3_API_DOCS = "/v3/api-docs";public static final String V2_API_DOCS = "/v2/api-docs";/*** 路由加载器*/private final RouteLocator routeLocator;private final MyGateWayProperties myGateWayProperties;/*** 网关应用名称*/@Value("${spring.application.name}")private String gateway;@Autowiredpublic SwaggerProvider(RouteLocator routeLocator, MyGateWayProperties myGateWayProperties) {this.routeLocator = routeLocator;this.myGateWayProperties = myGateWayProperties;}@Overridepublic List get() {List resources = new ArrayList<>();List routeHosts = new ArrayList<>();Flux routes = routeLocator.getRoutes();// 获取所有可用的host,因为是注册表服务调用,所以实际是服务名routes.filter(route -> route.getUri().getHost() != null).filter(route -> !gateway.equals(route.getUri().getHost())).subscribe(route -> routeHosts.add(route.getUri().getHost()));// 去重下拉列表相同服务名文档,多个服务展示一个,当网关调用这个接口时，会自动通过负载均衡寻找服务hostSet docServerSet = new HashSet<>();routeHosts.forEach(instance -> {String url;if (myGateWayProperties.getSwagger3Set().contains(instance)) {// 拼接url. /serviceId/v3/api-docsurl = myGateWayProperties.getApiPrefix() + "/" + instance.toLowerCase() + V3_API_DOCS;} else {// 拼接url. /serviceId/v2/api-docsurl = myGateWayProperties.getApiPrefix() + "/" + instance.toLowerCase() + V2_API_DOCS;}if (!docServerSet.contains(url)) {docServerSet.add(url);SwaggerResource swaggerResource = new SwaggerResource();swaggerResource.setUrl(url);swaggerResource.setName(instance);resources.add(swaggerResource);}});return resources;}
}

网关添加全局过滤器，发现以访问swagger3后缀的url则重新返回体，携带上bathPath

/*** @author lei* @create 2022-05-26 14:36* @desc swagger过滤器* 解决swagger3 响应缺少bathPath,请求无法动态路由到服务的问题**/
@Log4j2
@Component
public class SwaggerGlobalFilter implements GlobalFilter, Ordered {public static final String BASE_PATH = "basePath";private final MyGateWayProperties myGateWayProperties;public SwaggerGlobalFilter(MyGateWayProperties myGateWayProperties) {this.myGateWayProperties = myGateWayProperties;}@Overridepublic Mono filter(ServerWebExchange exchange, GatewayFilterChain chain) {String path = exchange.getRequest().getPath().toString();if (!path.endsWith(SwaggerProvider.V3_API_DOCS)) {return chain.filter(exchange);}path = path.replace(myGateWayProperties.getApiPrefix(), "");String[] pathArray = path.split("/");String basePath = pathArray[1];ServerHttpResponse originalResponse = exchange.getResponse();ServerHttpResponseDecorator newResponse = new ServerHttpResponseDecorator(originalResponse) {@Overridepublic Mono writeWith(Publisher body) {if (!Objects.equals(getStatusCode(), HttpStatus.OK)) {return super.writeWith(body);}if (body instanceof Flux) {Flux fluxBody = Flux.from(body);return super.writeWith(fluxBody.buffer().map(dataBuffers -> {List list = new ArrayList<>();dataBuffers.forEach(dataBuffer -> {byte[] content = new byte[dataBuffer.readableByteCount()];dataBuffer.read(content);DataBufferUtils.release(dataBuffer);list.add(new String(content, StandardCharsets.UTF_8));});String jsonStr = listToString(list);JSONObject jsonObject = JSON.parseObject(jsonStr);jsonObject.put(BASE_PATH, myGateWayProperties.getApiPrefix() + "/" + basePath);jsonStr = jsonObject.toString();return bufferFactory().wrap(jsonStr.getBytes());}));}return super.writeWith(body);}@Overridepublic HttpHeaders getHeaders() {HttpHeaders httpHeaders = new HttpHeaders();httpHeaders.putAll(super.getHeaders());//由于修改了请求体的body，导致content-length长度不确定，因此使用分块编码httpHeaders.remove(HttpHeaders.CONTENT_LENGTH);httpHeaders.set(HttpHeaders.TRANSFER_ENCODING, "chunked");return httpHeaders;}private String listToString(List list) {StringBuilder stringBuilder = new StringBuilder();for (String s : list) {stringBuilder.append(s);}return stringBuilder.toString();}};return chain.filter(exchange.mutate().response(newResponse).build());}@Overridepublic int getOrder() {return -2;}
}

网关获取到文档访问列表

访问具体服务的文档，触发全局过滤器

改写响应数据，访问swagger3文档，带上了bathPath

访问swagger2文档时，不受影响