Stop current thread & wait for HTTP connection

Question

I am running some logic in a Thread that depends on a HTTP connection to a remote server. Currently, the thread crashes, if the remote server is not running. I want to modify the logic so that the thread waits for the remote server to become available again.

Technically, the solution seems strait forward. Something along the lines of:

                boolean reconnect = false;

                while (!reconnect) {
                    try {
                        URL url = new URL("my.remoteserver.com");
                        HttpURLConnection connection = (HttpURLConnection) url.openConnection();
                        connection.connect();
                        reconnect = true;
                    } catch (Exception ex) {
                        // wait a little, since remote server seems still down
                        try {
                            Thread.sleep(5000);
                        } catch (InterruptedException e1) {
                            // if thread was interrupted while waiting then terminate thread
                            break;
                        }
                    }
                }

However, this solution is not very elegant. Also, the use case seems so generic that I suspect this could be done by some helpful library. Alas, I could not find any - who can tell me how to improve my solution?

Answer 1

I think this use case is simple enough to implement yourself instead of introducing additional dependencies. If you are concerned about your solution not being very elegant I suggest refactoring it into a couple of smaller methods, for example like this:

public void connect() {
    try {
        connectWithRetries();
    } catch (InterruptedException e) {
        // Continue execution
    }
}

private void connectWithRetries() throws InterruptedException {
    while (!tryConnect()) {
        sleep();
    }
}

private boolean tryConnect() {
    try {
        URL url = new URL("my.remoteserver.com");
        HttpURLConnection connection = (HttpURLConnection) url.openConnection();
        connection.connect();
    } catch (Exception e) {
        return false;
    }
    return true;
}

private void sleep() throws InterruptedException {
    Thread.sleep(5000);
}