Properly close of URLConnection using openStream method

Question

I'm getting a little bit confused about how properly close/manage an URLConnection/HttpURLConnection, the next code shows how I'm deal with it:

String someIP = "...";
URL url = new URL(someIP);
try (BufferedReader br = new BufferedReader(new InputStreamReader(url.openStream()))) {
    while ((res = br.readLine()) != null) {
        cad.append(res);
    }
}

I'm thinking to change the implementation to the next one, using an HttpURLConnection and closing later in finally clause:

String someIP = "...";
URL url = new URL(someIP);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
try (InputStreamReader isr = new InputStreamReader(conn.getInputStream());
        BufferedReader br = new BufferedReader(isr)) {
    while ((res = br.readLine()) != null) {
        cad.append(res);
    }
} 
catch (Exception e) {
    //ex....
}
finally {
    if (conn != null) {
        conn.disconnect();
    }
}

It is enough to use a try with resources to properly close the BufferedReader, InputStreamReader and URLConnection? Or the second implementation is better, what advices could you give me to handle it.