HttpURLConnection inside a loop

I'm trying to connect to one URL that I know that exist but I don't know when. I don't have access to this server so I can't change anything to receive a event.

The actual code is this.

URL url = new URL(urlName);
for(int j = 0 ; j< POO开发者_如何学CLING && disconnected; j++){
    HttpURLConnection connection = (HttpURLConnection) url.openConnection();
    int status = connection.getResponseCode();
    if(status == HttpURLConnection.HTTP_OK || status == HttpURLConnection.HTTP_NOT_MODIFIED){
        //Some work
    }else{
        //wait 3s
        Thread.sleep(3000);       
    }
}

Java not is my best skill and I'm not sure if this code is good from the point of view of performance. I'm opening a new connection every 3 seconds? or the connection is reused?

If I call to disconnect() I ensure that no new connections are open in the loop, but... it will impact in performance?.

Suggestions? What is the fast/best ways to know it a URL exist?

1) Do use disconnect, you don't want numerous open connections you don't use. Discarding resources you don't use is a basic practice in any language.
2) I don't know if opening and closing new network connection every 3 seconds will pollute system resources, the only way to check it is to try.
3) You may want to watch for 'ConnectException', if by "URL [does not] exist" you mean server is down.

This code is okay from a performance point of view, it will create a new connection each time. Anyway if you have a Thread.sleep(3000) in your loop, you shouldn't have to worry about performance ;)

If you're concerned about connection usage on the server side, you can look into apache HTTP client, it has a lot of features. I think it handles keep alive connections by default.