title: Spring Cloud Feign: Is Feign efficient enough compared with RestTemplate?
body: <p>I quickly browsed the source code of Feign, I found that Feign uses JDK's <code>HttpUrlConnection</code> to issue HTTP request and close it when request finished without using a connection pool. I doubt the efficiency of this kind of manner. Then I read the document of Spring's <code>RestTemplate</code> which says <code>RestTemplate</code> can switch to Apache Http Client or OKHttp to send HTTP request:</p>
  
  <blockquote>
    <p>Note: by default the RestTemplate relies on standard JDK facilities to establish HTTP connections. You can switch to use a different HTTP library such as Apache HttpComponents, Netty, and OkHttp through the HttpAccessor.setRequestFactory(org.springframework.http.client.ClientHttpRequestFactory) property.</p>
  </blockquote>
  
  <p>Does it mean RestTemplate is better than Feign at the view of performance?</p>