Connection and connection request timeout

问题:

I am using Http Apache Components to perform the http interactions. I need to adjust my http client. For this purpose I have two parameters: connection timeout and connection request timeout. In library documentation and in source code(no comments were found) I didn't found definition of this terms. I need to know what do they exactly mean. May be they were defined in HTTP protocol documentation but I can't find it. So, my question is what do this two terms mean and how they distinct from each other.

回答1:

HttpClient has a way to set connection and socket timeout (setConnectionTimeout() and setTimeout()) according to http://hc.apache.org/httpclient-3.x/apidocs/org/apache/commons/httpclient/HttpClient.html

Connection timeout is the timeout until a connection with the server is established.

Socket timeout is the timeout to receive data (socket timeout).

Example:

Let's say you point your browser to access a web page. If the server does not anwser in X seconds, a connection timeout will occur. But if it establishes the connection, then the server will start to process the result for the browser. If it does not ends this processing in Y seconds, a socket timeout will occur.

回答2:

In HttpClient 4.X.X , the following is how you build a client that uses a particular connectTimeoutMillis and requestTimeoutMillis.

HttpClientBuilder clientBuilder = HttpClientBuilder.create();
RequestConfig.Builder requestBuilder = RequestConfig.custom();
requestBuilder = requestBuilder.setConnectTimeout(connectTimeoutMillis);
requestBuilder = requestBuilder.setConnectionRequestTimeout(requestTimeoutMillis);
clientBuilder.setDefaultRequestConfig(requestBuilder.build());
CloseableHttpClient httpClient = clientBuilder.build();
...

Btw, the javadocs for this code sucks. Try to figure out by hand how to use the config builder. Holy crap.