在微服务架构下，通常每个微服务都会使用Swagger来管理我们的接口文档，当微服务越来越多，接口查找管理无形中要浪费我们不少时间，毕竟懒是程序员的美德。

Spring Cloud Gateway 实现

注入路由到SwaggerResource
@Component
@Primary
@AllArgsConstructor
public class SwaggerProvider implements SwaggerResourcesProvider {
public static final String API_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<>();
    routeLocator.getRoutes().subscribe(route -> routes.add(route.getId()));
    gatewayProperties.getRoutes().stream().filter(routeDefinition -> routes.contains(routeDefinition.getId()))
        .forEach(routeDefinition -> routeDefinition.getPredicates().stream()
            .filter(predicateDefinition -> "Path".equalsIgnoreCase(predicateDefinition.getName()))
            .filter(predicateDefinition -> !"pigx-auth".equalsIgnoreCase(routeDefinition.getId()))
            .forEach(predicateDefinition -> resources.add(swaggerResource(routeDefinition.getId(),
                predicateDefinition.getArgs().get(NameUtils.GENERATED_NAME_PREFIX + "0")
                    .replace("/**", API_URI)))));
    return resources;
}

private SwaggerResource swaggerResource(String name, String location) {
    SwaggerResource swaggerResource = new SwaggerResource();
    swaggerResource.setName(name);
    swaggerResource.setLocation(location);
    swaggerResource.setSwaggerVersion("2.0");
    return swaggerResource;
}

}

提供swagger 对外接口配置



@Slf4j
@Configuration
@AllArgsConstructor
public class RouterFunctionConfiguration {
private final SwaggerResourceHandler swaggerResourceHandler;
private final SwaggerSecurityHandler swaggerSecurityHandler;
private final SwaggerUiHandler swaggerUiHandler;

@Bean
public RouterFunction routerFunction() {
    return RouterFunctions.route(
        .andRoute(RequestPredicates.GET("/swagger-resources")
            .and(RequestPredicates.accept(MediaType.ALL)), swaggerResourceHandler)
        .andRoute(RequestPredicates.GET("/swagger-resources/configuration/ui")
            .and(RequestPredicates.accept(MediaType.ALL)), swaggerUiHandler)
        .andRoute(RequestPredicates.GET("/swagger-resources/configuration/security")
            .and(RequestPredicates.accept(MediaType.ALL)), swaggerSecurityHandler);

}

}

业务handler 的实现

@Override
public Mono<ServerResponse> handle(ServerRequest request) {
    return ServerResponse.status(HttpStatus.OK)
        .contentType(MediaType.APPLICATION_JSON_UTF8)
        .body(BodyInserters.fromObject(swaggerResources.get()));
}

@Override
public Mono<ServerResponse> handle(ServerRequest request) {
    return ServerResponse.status(HttpStatus.OK)
        .contentType(MediaType.APPLICATION_JSON_UTF8)
        .body(BodyInserters.fromObject(
            Optional.ofNullable(securityConfiguration)
                .orElse(SecurityConfigurationBuilder.builder().build())));
}

@Override
public Mono<ServerResponse> handle(ServerRequest request) {
    return ServerResponse.status(HttpStatus.OK)
        .contentType(MediaType.APPLICATION_JSON_UTF8)
        .body(BodyInserters.fromObject(
            Optional.ofNullable(uiConfiguration)
                .orElse(UiConfigurationBuilder.builder().build())));
}

swagger路径转换

通过以上配置，可以实现文档的参考和展示了，但是使用swagger 的 try it out 功能发现路径是路由切割后的路径比如：

swagger 文档中的路径为： 主机名：端口：映射路径 少了一个 服务路由前缀，是因为展示handler 经过了 StripPrefixGatewayFilterFactory 这个过滤器的处理，原有的 路由前缀被过滤掉了！

方案1，通过swagger 的host 配置手动维护一个前缀

return new Docket(DocumentationType.SWAGGER_2)
.apiInfo(apiInfo())
.host(“主机名：端口：服务前缀”) //注意这里的主机名：端口是网关的地址和端口
.select()
.apis(RequestHandlerSelectors.withMethodAnnotation(ApiOperation.class))
.paths(PathSelectors.any())
.build()
.globalOperationParameters(parameterList);

方案2，增加X-Forwarded-Prefix

swagger 在拼装URL 数据时候，会增加X-Forwarder-Prefix 请求头里面的信息为前缀

通过如上分析，知道应该在哪里下手了吧，在 网关上追加一个请求头即可

@Component
public class SwaggerHeaderFilter extends AbstractGatewayFilterFactory {
private static final String HEADER_NAME = “X-Forwarded-Prefix”;

@Override
public GatewayFilter apply(Object config) {
    return (exchange, chain) -> {
        ServerHttpRequest request = exchange.getRequest();
        String path = request.getURI().getPath();
        if (!StringUtils.endsWithIgnoreCase(path, SwaggerProvider.API_URI)) {
            return chain.filter(exchange);
        }

        String basePath = path.substring(0, path.lastIndexOf(SwaggerProvider.API_URI));


        ServerHttpRequest newRequest = request.mutate().header(HEADER_NAME, basePath).build();
        ServerWebExchange newExchange = exchange.mutate().request(newRequest).build();
        return chain.filter(newExchange);
    };
}

}