如果您不定义HttpClient,它将充当连接,可以无限期地保持活动,从
   
    Apache http docs
   
  
  
   
    如果响应中不存在Keep-Alive标头,则HttpClient
假设连接可以无限期保持活动。
   
  
  
   如果要定义“保持活力”策略,请参阅
   
    example
   
  
  ConnectionKeepAliveStrategy myStrategy = new ConnectionKeepAliveStrategy() {
    @Override
    public long getKeepAliveDuration(HttpResponse response, HttpContext context) {
        HeaderElementIterator it = new BasicHeaderElementIterator
            (response.headerIterator(HTTP.CONN_KEEP_ALIVE));
        while (it.hasNext()) {
            HeaderElement he = it.nextElement();
            String param = he.getName();
            String value = he.getValue();
            if (value != null && param.equalsIgnoreCase
               ("timeout")) {
                return Long.parseLong(value) * 1000;
            }
        }
        return 5 * 1000;
    }
};