java - 使用 httpclient 的连接持久性

Question

我使用 httpclient.execute(request) 对同一个 url 进行多次请求。 我可以为连续的请求重新使用连接吗？ 如何在不一次又一次声明 HttpClient 的情况下优化代码。

for(int i=0;i<=50;i++)
{
HttpClient client = new DefaultHttpClient();
HttpGet request = new HttpGet("my_url");
HttpResponse response = client.execute(request);
System.out.println(response.getStatusLine().getStatusCode());
}

Answer 1

为了在您的代码中使用单个客户端(基于 Exception using HttpRequest.execute(): Invalid use of SingleClientConnManager: connection still allocated 和 Lars Vogel Apache HttpClient - Tutorial ):

• 第 1 步。将客户端生成移到 for 循环 之外。

• 第 2 步。您应该阅读响应内容并关闭流。如果你不这样做，你将得到以下异常

  Exception in thread "main" java.lang.IllegalStateException: 
      Invalid use of SingleClientConnManager: connection still allocated.
  

在代码中:

//step 1
HttpClient client = new DefaultHttpClient();
for(int i=0;i<=50;i++) {
    HttpGet request = new HttpGet("my_url");
    HttpResponse response = client.execute(request);
    System.out.println(response.getStatusLine().getStatusCode());
    //step 2
    BufferedReader br = new BufferedReader(
        new InputStreamReader(response.getEntity().getContent()));
    //since you won't use the response content, just close the stream
    br.close();
}