Httpurlconnection timeout settings

java

httpurlconnection

timeout-settings

network-conditions

byAlex Kataev·Feb 23, 2025

Establishing a safe and efficient timeout in HttpURLConnection is paramount. Specifically, setConnectTimeout() defines the maximum time to successfully connect, and setReadTimeout() prescribes the threshold to fetch data.

HttpURLConnection con = (HttpURLConnection) new URL("http://example.com").openConnection();
con.setConnectTimeout(5000); // 5s to connect (just enough time to drink a shot of espresso ☕)
con.setReadTimeout(10000); // 10s to read (or to enjoy a doughnut 🍩)

In the event of a timeout, java.net.SocketTimeoutException is thrown, which you should handle gracefully.

Redirect handling is also crucial:

HttpURLConnection.setFollowRedirects(false); // Kindly ask HttpURLConnection not to follow redirects. We like to take the scenic route. 🏞️

For a fast URL validity check, use a HEAD request:

con.setRequestMethod("HEAD"); // No need for the full monty. A 'HEAD' request will do.

Lastly, ensure your communication is both ways by checking the server's response:

if (con.getResponseCode() == HttpURLConnection.HTTP_OK) {
    // We're in business! 💼
}

Naturally, adjust these settings according to your application's requirements.

Understanding connect and read timeouts

The "connect" timeout

setConnectTimeout(int timeout) sets up the duration for establishing the communication link. When the time's up before a connection is made, our friend java.net.SocketTimeoutException pops up.

The "read" timeout

setReadTimeout(int timeout) decides the maximum period for a read from the InputStream. If the read lags, it also throws a java.net.SocketTimeoutException.

Global timeout settings

To set a uniform rule for all HttpURLConnection instances, tweak the system property sun.net.client.defaultConnectTimeout. Proceed with caution as it impacts the whole application.

System.setProperty("sun.net.client.defaultConnectTimeout", "5000");
System.setProperty("sun.net.client.defaultReadTimeout", "10000");

Overriding custom timeout threads

Favour the built-in timeout methods of HttpURLConnection over the creation of separate threads or AsyncTask — these can be more error-prone and resource-hungry.

Not forgetting the network

Consider network conditions and server responsiveness when setting your timeouts. A slow network or a busy server would need more patience, hence a longer timeout.

The quick and elegant HEAD request

Instead of a GET request, use con.setRequestMethod("HEAD") when you only need to fetch headers. Reading headlines is always quicker than reading the entire news article!