How to Ping an HTTP URL for Availability in Java

What is the preferred method in Java for pinging an HTTP URL to check its availability?

try {
    final URLConnection connection = new URL(url).openConnection();
    connection.connect();
    LOG.info("Service " + url + " available, yeah!");
    available = true;
} catch (final MalformedURLException e) {
    throw new IllegalStateException("Bad URL: " + url, e);
} catch (final IOException e) {
    LOG.info("Service " + url + " unavailable, oh no!", e);
    available = false;
}

To effectively check the availability of an HTTP URL in Java, consider using the `HttpURLConnection` class instead of `URLConnection`. This allows for a more controlled handling of HTTP requests, including the ability to send specific request methods like HEAD. Furthermore, managing resources properly (such as closing connections) is essential for avoiding resource leaks.

try {
    HttpURLConnection connection = (HttpURLConnection) new URL(url).openConnection();
    connection.setRequestMethod("HEAD");
    connection.setConnectTimeout(2000); // Set a timeout for the connection
    connection.setReadTimeout(2000);
    int responseCode = connection.getResponseCode();
    if (responseCode == HttpURLConnection.HTTP_OK) {
        LOG.info("Service " + url + " is available!");
        available = true;
    } else {
        LOG.info("Service " + url + " is unavailable! Response Code: " + responseCode);
        available = false;
    }
} catch (final MalformedURLException e) {
    throw new IllegalStateException("Bad URL: " + url, e);
} catch (final IOException e) {
    LOG.info("Service 

Causes

• Using `URLConnection` may not provide control over specific HTTP methods (GET, HEAD).
• Failure to close connections can lead to resource leaks or connection timeouts.
• Not checking the response code may provide an incorrect assessment of the URL's availability.

Solutions

• Utilize the `HttpURLConnection` class for HTTP-specific functionality.
• Explicitly close the connection using `disconnect()` after checking availability.
• Use the HEAD method for a lightweight availability check.

Mistake: Not using `HttpURLConnection` which doesn't allow specifying HTTP methods directly.

Solution: Switch to using `HttpURLConnection` for better control over the request.

Mistake: Forgetting to close the connection after checking the URL availability.

Solution: Always call `connection.disconnect()` to close the connection.

Mistake: Using GET method when only availability is needed without the payload.

Solution: Use the HEAD method for checking availability without fetching the resource.