RestTemplate动态修改请求的url

背景

在项目中有个通过线程池发送大量http请求是通过restTemplate 实现的，在研发环境需要直接连某些服务，所以需要动态修改请求的url。

自定义 ClientHttpRequestInterceptor 拦截器修改请求

自定义 ClientHttpRequestInterceptor 在请求发送前修改 URL：

public class DynamicUrlInterceptor implements ClientHttpRequestInterceptor {@Overridepublic ClientHttpResponse intercept(HttpRequest request, byte[] body, ClientHttpRequestExecution execution)throws IOException {URI originalUri = request.getURI();String originalUrl = originalUri.toString();String host = originalUri.getHost();// 替换服务名为 IPif (SERVICE_MAP.containsKey(host)) {String newUrl = originalUrl.replace("http://" + host, SERVICE_MAP.get(host));try {// 创建新的请求对象HttpRequest newRequest = new HttpRequestWrapper(request, new URI(newUrl));return execution.execute(newRequest, body);} catch (URISyntaxException e) {throw new IOException("Invalid URI after replacing service name", e);}}return execution.execute(request, body);}
}

注册拦截器

RestTemplateConfig 配置

public class RestTemplateConfig {private static final Logger logger = LoggerFactory.getLogger(RestTemplateConfig.class);@Autowiredprivate HttpClinetProperties httpClinetProperties;@Bean(name="httpClientTemplate")public RestTemplate restTemplate() {// 使用http连接池RestTemplate restTemplate = new RestTemplate(httpRequestFactory());//配置自定义的interceptor拦截器List<ClientHttpRequestInterceptor> interceptors=new ArrayList<ClientHttpRequestInterceptor>();interceptors.add(new DynamicUrlInterceptor());restTemplate.setInterceptors(interceptors);return restTemplate;}@Beanpublic ClientHttpRequestFactory httpRequestFactory() {return new HttpComponentsClientHttpRequestFactory(httpClient());}public HttpClient httpClient(){RequestConfig.Builder requestConfigBuilder = RequestConfig.custom();requestConfigBuilder.setSocketTimeout(httpClinetProperties.getSocketTimeout());requestConfigBuilder.setConnectionRequestTimeout(httpClinetProperties.getConnectionRequestTimeout());requestConfigBuilder.setConnectTimeout(httpClinetProperties.getConnectTimeout());RequestConfig defaultRequestConfig = requestConfigBuilder.build();final PoolingHttpClientConnectionManager pollingConnectionManager = new PoolingHttpClientConnectionManager(30, TimeUnit.SECONDS);pollingConnectionManager.setMaxTotal(httpClinetProperties.getMaxTotal());pollingConnectionManager.setDefaultMaxPerRoute(httpClinetProperties.getDefaultMaxPerRoute());HttpClientBuilder httpClientBuilder = HttpClientBuilder.create();httpClientBuilder.setKeepAliveStrategy(new DefaultConnectionKeepAliveStrategy());httpClientBuilder.setConnectionManager(pollingConnectionManager);httpClientBuilder.setDefaultRequestConfig(defaultRequestConfig);HttpClient client = httpClientBuilder.build();Timer timer = new Timer();timer.schedule(new TimerTask() {@Overridepublic void run() {pollingConnectionManager.closeExpiredConnections();pollingConnectionManager.closeIdleConnections(5, TimeUnit.SECONDS);}}, 10 * 1000, 5 * 1000);return client;}
}