Knife4j在Gateway下的URI优化以及热刷新

契机

（遗留输出）最近在整理之前的笔记，逐渐梳理成文章输出到博客网站。之前在做Gateway集成knife4j的时候。发现uri的地址缺少了项目路径，也就是baseURI，本篇文章就是在处理这个问题。还有gateway一旦启动会固化服务列表，加了一个小改动动态刷新服务列表，这样不用每次在最后重启gateway。

添加BaseURI

@Slf4j
@Component
public class SwaggerGlobalFilter implements GlobalFilter, Ordered {

    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        ServerHttpRequest request = exchange.getRequest();
        String path = request.getPath().toString();
        if (!path.endsWith("/v3/api-docs")) {
            return chain.filter(exchange);
        }
        String[] pathArray = path.split("/");
        String basePath = pathArray[1];
        ServerHttpResponse originalResponse = exchange.getResponse();
        // 定义新的消息头
        ServerHttpResponseDecorator decoratedResponse = new ServerHttpResponseDecorator(originalResponse) {
            @Override
            public @NotNull Mono<Void> writeWith(@NotNull Publisher<? extends DataBuffer> body) {
                if (Objects.equals(super.getStatusCode(), HttpStatus.OK) && body instanceof Flux) {
                    Flux<? extends DataBuffer> fluxBody = Flux.from(body);
                    return super.writeWith(fluxBody.buffer().map(dataBuffers -> {
                        List<String> 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 s = this.listToString(list);
                        JSONObject jsonObject = JSON.parseObject(s);

                        //给所有url加上basePath前缀
                        JSONObject test = new JSONObject();
                        for (String paths : jsonObject.getJSONObject("paths").keySet()) {
                            test.put("/" + basePath + paths, jsonObject.getJSONObject("paths").getJSONObject(paths));
                        }
                        jsonObject.remove("paths");
                        jsonObject.put("paths", test);
                        s = jsonObject.toString();
                        int length = s.getBytes().length;
                        HttpHeaders headers = originalResponse.getHeaders();
                        headers.setContentLength(length);
                        return bufferFactory().wrap(s.getBytes(StandardCharsets.UTF_8));
                    }));
                }
                return super.writeWith(body);
            }

            @Override
            public @NotNull HttpHeaders getHeaders() {
                // 获取父类原始ServerHttpResponse的header请求头信息，这是代理Delegate类型
                HttpHeaders httpHeaders = super.getHeaders();
                httpHeaders.set(HttpHeaders.CONTENT_TYPE, "application/json;charset=UTF-8");
                return httpHeaders;
            }

            private String listToString(List<String> list) {
                StringBuilder stringBuilder = new StringBuilder();
                for (String s : list) {
                    stringBuilder.append(s);
                }
                return stringBuilder.toString();
            }
        };

        // replace response with decorator
        return chain.filter(exchange.mutate().response(decoratedResponse).build());
    }

    @Override
    public int getOrder() {
        return -2;
    }

}

动态刷新服务列表

@Configuration(proxyBeanMethods = false)
@Slf4j
public class SpringDocConfiguration {

    @Bean
    @Lazy(false)
    @ConditionalOnProperty(name = "springdoc.api-docs.enabled", matchIfMissing = true)
    public List<GroupedOpenApi> apis(SwaggerUiConfigParameters swaggerUiConfigParameters,
        SwaggerDocProperties swaggerProperties) {
        List<GroupedOpenApi> groups = new ArrayList<>();
        for (String value : swaggerProperties.getServices().values()) {
            swaggerUiConfigParameters.addGroup(value);
        }
        return groups;
    }

    @Data
    @Component
    @ConfigurationProperties("swagger")
    public class SwaggerDocProperties implements InitializingBean {

        private final ScheduledExecutorService scheduledExecutorService = Executors.newSingleThreadScheduledExecutor();

        Set<AbstractSwaggerUiConfigProperties.SwaggerUrl> urlsBackup = new HashSet<>();

        @Override
        public void afterPropertiesSet() {
            scheduledExecutorService.scheduleWithFixedDelay(new DelayTaskHandler(), 3, 3, TimeUnit.SECONDS);

        }

        public class DelayTaskHandler implements Runnable {

            @SneakyThrows
            @Override
            public void run() {
                try {
                    Set<String> ignoreServices = new HashSet<>();
                    //遍历
                    for (String s : services.keySet()) {
                        NacosDiscoveryClient bean = SpringUtil.getBean(NacosDiscoveryClient.class);
                        if (!bean.getServices().contains(s)) {
                            ignoreServices.add(services.get(s));
                        }
                    }
                    SwaggerUiConfigParameters swaggerUiConfigParameters = SpringUtil.getBean(
                        SwaggerUiConfigParameters.class);
                    Set<AbstractSwaggerUiConfigProperties.SwaggerUrl> urls = swaggerUiConfigParameters.getUrls();
                    if (urlsBackup.size() == 0) {
                        urlsBackup.addAll(urls);
                    }
                    urls.clear();
                    for (AbstractSwaggerUiConfigProperties.SwaggerUrl url : urlsBackup) {
                        if (!ignoreServices.contains(url.getName())) {
                            urls.add(url);
                        }
                    }
                    swaggerUiConfigParameters.setUrls(urls);
                } catch (Exception e) {
                    log.error(e.getMessage());
                }

            }
        }

        private Map<String, String> services;

        /**
         * 认证参数
         */
        private SwaggerBasic basic = new SwaggerBasic();

        @Data
        public class SwaggerBasic {

            /**
             * 是否开启 basic 认证
             */
            private Boolean enabled;

            /**
             * 用户名
             */
            private String username;

            /**
             * 密码
             */
            private String password;

        }

    }

}

总结

• 有点水
• 纯记录，后续都使用apifox了

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