java - HttpClient 4.0.1 - 如何释放连接？

Question

这个问题在这里已经有了答案:

What is the difference between CloseableHttpClient and HttpClient in Apache HttpClient API? (8 个回答)

关闭 2年前。

我对一堆 URL 进行了循环，对于每个 URL，我都在执行以下操作:

private String doQuery(String url) {

  HttpGet httpGet = new HttpGet(url);
  setDefaultHeaders(httpGet); // static method
  HttpResponse response = httpClient.execute(httpGet);   // httpClient instantiated in constructor

  int rc = response.getStatusLine().getStatusCode();

  if (rc != 200) {
    // some stuff...
    return;
  }

  HttpEntity entity = response.getEntity();

  if (entity == null) {
    // some stuff...
    return;
  }

  // process the entity, get input stream etc

}

第一个查询没问题，第二个抛出这个异常:

Exception in thread "main" java.lang.IllegalStateException: Invalid use of SingleClientConnManager: connection still allocated. Make sure to release the connection before allocating another one. at org.apache.http.impl.conn.SingleClientConnManager.getConnection(SingleClientConnManager.java:199) at org.apache.http.impl.conn.SingleClientConnManager$1.getConnection(SingleClientConnManager.java:173)......

这只是一个简单的单线程应用程序。如何释放此连接？

Answer 1

Httpcomponents 4.1 推荐的方法是关闭连接并释放任何底层资源:

EntityUtils.consume(HttpEntity)

其中 HttpEntity 传递的是响应实体。