标签：京东 override err tde 默认 param def show ntc
httpclient使用了连接池，如果没有设置keep-alive策略，PoolingHttpClientConnectionManager会默认使用永久连接。
最近在调用京东api时，发现一个请求开始是可以获取到数据的，但隔了两分钟后再请求就会出现read timeout异常。对比请求成功和请求失败的日志后发现，请求成功的有以下日志“Connection: keep-alive”，“Connection can be kept alive indefinitely”；但请求失败的却打印“Shutdown connection”，“Connection discarded”。每次失败后再请求都会成功。因此推测中应该是对方服务器端禁止长连接，当连接到达一定时间会就会断开。后来上网找到keep-alive策略的代码，添加策略后，问题解决。
1 ConnectionKeepAliveStrategy keepAliveStrategy = new ConnectionKeepAliveStrategy() { 2 3 @Override 4 public long getKeepAliveDuration(HttpResponse response, HttpContext context) { 5 HeaderElementIterator it = new BasicHeaderElementIterator(response.headerIterator(HTTP.CONN_KEEP_ALIVE)); 6 while (it.hasNext()) { 7 HeaderElement he = it.nextElement(); 8 String param = he.getName(); 9 String value = he.getValue(); 10 if (value != null && param.equalsIgnoreCase("timeout")) { 11 try { 12 return Long.parseLong(value) * 1000; 13 } 14 catch (NumberFormatException ignore) { 15 16 } 17 } 18 } 19 HttpHost target = (HttpHost) context.getAttribute(HttpClientContext.HTTP_TARGET_HOST); 20 if ("bizapi.jd.com ".equalsIgnoreCase(target.getHostName())) { 21 return 60 * 1000; 22 } 23 else { 24 return 300 * 1000; 25 } 26 27 CloseableHttpClient httpClient = httpClientBuilder.setConnectionManager(pollingConnectionManager) 28 .setKeepAliveStrategy(keepAliveStrategy).setDefaultRequestConfig(defaultRequestConfig).build();
解决httpclient因为保持永久长连接造成连接吊死的问题
标签：京东 override err tde 默认 param def show ntc
原文地址：http://www.cnblogs.com/BensonHe/p/7612474.html
