HttpClient的NoHttpResponse問題

     調用第三方接口時會報NoHttpResponse異常，原因是上次的連接已經斷掉了，但是客戶端並未知道，復用上次連接就報錯了，所以要解決這個問題，就是要校驗上次鏈接是否斷掉了

 1. httpClient已經給我們實現了這個，setRetryHandler

public static RestTemplate builRestTemplate() {
        SSLConnectionSocketFactory sf = null;
        try {
            sf = new SSLConnectionSocketFactory(new SSLContextBuilder().loadTrustMaterial(null, new TrustSelfSignedStrategy()).build(), new NoopHostnameVerifier());
        } catch (NoSuchAlgorithmException | KeyManagementException | KeyStoreException e) {
            logger.error("SSL related failure: {} ", e.getMessage());
            throw new CloudChefException("SSL error");
        }

        CloseableHttpClient httpClient = HttpClients.custom().setSSLSocketFactory(sf).setRetryHandler((exception, executionCount, context) -> { if (executionCount > 3) { //重試3次，大於3次則結束 logger.warn("Maximum tries reached for client http pool "); return false; } if (exception instanceof org.apache.http.NoHttpResponseException) { //如果是NoHttpResponseException則進行重試 logger.warn("No response from server on " + executionCount + " call"); return true; } return false; }).build();

        HttpComponentsClientHttpRequestFactory requestFactory = new HttpComponentsClientHttpRequestFactory();
        requestFactory.setHttpClient(httpClient);
        configureTimeout(requestFactory);
        return new RestTemplate(requestFactory);
    }

    private static void configureTimeout(HttpComponentsClientHttpRequestFactory factory) {
        //默認http request超時設置
        factory.setReadTimeout(120_1000);
        factory.setConnectTimeout(15_1000);
        factory.setConnectionRequestTimeout(15_1000);
    }

2.或者使用 DefaultHttpRequestRetryHandler

HttpClientBuilder clientBuilder = HttpClients.custom();
clientBuilder.setRetryHandler(new DefaultHttpRequestRetryHandler(3, true));

 

對於這個問題的分析有一個不錯的博客，寫的不錯：https://czjxy881.github.io/java,nginx/%E8%AE%B0HttpClient%E7%9A%84NoHttpResponse%E9%97%AE%E9%A2%98/　

對於解決方案，來自於：https://stackoverflow.com/questions/10570672/get-nohttpresponseexception-for-load-testing/10680629#10680629