Retrieving server info with Java

[GoldenBullet]

So this isn't really related to ET itself, but it kinda is and I need help with it so I posted it here.

Anyway, I've had this small idea for an android app I wanted to try make. It would check the server regularly and if there were enough players online, it would give an alarm to the phone.

However this made me think how could I retrieve the server info itself like in the server monitor. Is there a way to get, like, an XML-file out of it which I could parse in Java? I mostly need the playerlist and their pings.

[OliVier_ Profile]

Hello,

i don't know if there is a java implementation out there, but this is a good looking php implementation,
you just have to translate it into java: https://github.com/adawolfa/etwsl/blob/master/src/ServerQuery.php
Its a matter of a few sockets


You basically send a getstatus request on a udp socket and it sends you all the info it has

[GoldenBullet]

Thanks for the info Olivier. So the request seems to be (in PHP)
@fwrite($socket, str_repeat(chr(255), 4) . "getstatus\n");

What bugs me is that str_repeat. It seems to repeat ÿ four times and I don't understand why.
To open all the variables, the request would look like

udp://xx.xx.xx.xx:yy ÿÿÿÿ.getstatus

maybe it's some php-spesific feature?

In java, the socket code would probably be something like:

Code: Select all

try (
    Socket connection = new Socket(hostName, portNumber);
    PrintWriter out =
        new PrintWriter(connection.getOutputStream(), true);
    BufferedReader in =
        new BufferedReader(
            new InputStreamReader(connection.getInputStream()));
)

Then put the "getstatus" into the "in" and read the result from the "out".

[OliVier_ Profile]

In java you will have to use the classes DatagramSocket / DatagramPacket to send and receive UDP packets, not the Socket class.

the '\xff\xff\xff\xff' produced by str_repeat(chr(255), 4) is just a header for the packets so you will have to include it in all the queries and it will be
included in the responses as well.

[Epa Profile]

start mining with rapids que htmml java, and see what happens if youll get your app ;exec

[Epa Profile]

tppshss

[Epa Profile]

https://www.youtube.com/watch?v=uEbBsWSzgxo

[Dr Zoidberg Profile]

Love the idea! Would definitly install that app on my phone. Whenever > 6 humans, notify me!

If I were you, instead of writing error-prone low-level socket requests with all that hassel... i'd just use JSoup + CSS selectors to parse necessary user information on PS from http://et.rapidhail.pl/. Disregard the "users" with ping 0 as these are bots. Voila =) Then poll the site as often as you want, like every minute.

Just wrote the code for you =) 20 lines of code. Enjoy =)

Enemy Territory Code: Select all

package whatever;

import java.io.IOException;

import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import org.jsoup.select.Elements;

public class whatever {

   public static void main(String[] args) {
      Document doc;
      try {
         int numberOfHumans = 0;
         int numberOfBots = 0;
         doc = Jsoup.connect("http://et.rapidhail.pl/").get();
         Elements trs = doc.select("table.server_tab tr[onmouseover=this.style.backgroundColor='#556677']");
         if (trs != null) {
            for (Element tr : trs) {
               Elements tds = tr.select("td");
               if (tds != null && tds.size() > 2) {
                  String username = tds.get(0).text();
                  String userxp = tds.get(1).text();
                  String userping = tds.get(2).text();
                  
                  if (userping.equals("0")) {
                     numberOfBots++;
                  } else {
                     numberOfHumans++;
                  }                  
               }
            }
         }
         System.out.println("number of bots: " + numberOfBots + ", number of humans: " + numberOfHumans);
      } catch (IOException e) {
         e.printStackTrace();
      }
   }
}

Enemy Territory Code: Select all

<dependency>
         <groupId>org.jsoup</groupId>
         <artifactId>jsoup</artifactId>
         <version>1.9.1</version>
      </dependency>

[OliVier_ Profile]

If I were you, instead of writing error-prone low-level socket requests with all that hassel...

outrageous socket bashing detected

[Dr Zoidberg Profile]

outrageous socket bashing detected

hehe true =)

//low-level-programming fan #6'999'999'999

[GoldenBullet]

I was thinking about that Zoid. I was going to exercise my programming skills by using the sockets.
But I suppose I could cut some corners since this is just a small hobby project.

Had there been a little more documentation I would have went with sockets.
Sorry Olivier, I have turned to the dark side :d

I'll see what I can come up with, but don't expect anything soon.

[Epa Profile]

I was thinking about that Zoid. I was going to exercise my programming skills by using the sockets.
But I suppose I could cut some corners since this is just a small hobby project.

Had there been a little more documentation I would have went with sockets.
Sorry Olivier, I have turned to the dark side :d

I'll see what I can come up with, but don't expect anything soon.

Should we start prime squadron server what could mine money for all members and regulars? If you make it, i can take it upon my name to get caught, prolly wont ever sit in jail, they promised me i don't even have to go to looneybin anymore.

Altho you need to red flag me or leave no evidence, its a pirates life for me eh

[Dr Zoidberg Profile]

Should we start prime squadron server what could mine money for all members and regulars? If you make it, i can take it upon my name to get caught, prolly wont ever sit in jail, they promised me i don't even have to go to looneybin anymore.

Altho you need to red flag me or leave no evidence, its a pirates life for me eh

But Epa, mining cryptocurrencies isnt illegal in most countries. =) You can even mine with your home computer if you'd like. No need for piracy... but I still recommend using an eye-patch while doing it, because hey... eye-patches are fun! =)

[Epa Profile]

Should we start prime squadron server what could mine money for all members and regulars? If you make it, i can take it upon my name to get caught, prolly wont ever sit in jail, they promised me i don't even have to go to looneybin anymore.

Altho you need to red flag me or leave no evidence, its a pirates life for me eh

But Epa, mining cryptocurrencies isnt illegal in most countries. =) You can even mine with your home computer if you'd like. No need for piracy... but I still recommend using an eye-patch while doing it, because hey... eye-patches are fun! =)

haha, i don't believe in money, just wondering if anyone hungry. I know everything anyone i've talked to or made eye contact with me knows.

[OliVier_ Profile]

from the light side

[GoldenBullet]

That looks pretty neat!
Did the getstatus work as predicted?

[OliVier_ Profile]

Did the getstatus work as predicted?

Of course

But java sucks in sending raw packets


Edit: uploaded an APK, could you test it ?
sorry i stole you the idea but you know when you started..

Edit2: i suggest you set the refresh time to a lower value when you are not connected with wifi (like 8000)

[Dr Zoidberg Profile]

Just installed it, and it works beautifully =)
Well done guys!

Will this be open-source? ...you guys might have installed a keelogger, and will find out my awesome password: ILoveMyLittlePony! =) No, for real, not sure how easy it is to migrate to other games, but the potential is definitly there.

[OliVier_ Profile]

Yep so the code is hosted here

Also i attach a release version of the apk (may be a little bit more optimized)

[GoldenBullet]

Do you think the repeatable query task could be performed with ScheduledExecutorService instead of Handler/HandlerThread you've used?
I'll still try to make my own version, since I want to exercise Java :d

[OliVier_ Profile]

Do you think the repeatable query task could be performed with ScheduledExecutorService instead of Handler/HandlerThread you've used?
I'll still try to make my own version, since I want to exercise Java :d

I did not know that this class actually existed :O

Well, in both cases you will have to run a Service class and perform the scheduling in that class.
I did some research but i don't find a comparative between Handler/ScheduledExecutorService, only that ScheduledExecutorService is more the "java way" than the "android way" , those methods seems quite close but i don't see any problem in using that class.

In any way i think it is better than to use AlarmManager since we are working with potentially small delays

The issue with setting a long period in this app is that the sockets may timeout when we are located in an area with poor GSM conn.
resulting in not being notified at all, so we have to perform requests often enough.

[GoldenBullet]

Actually now that I think of it, we might be making the program a little differently. I couldn't install your app (not sure if it would run on my phone, it has an antique android version), but there doesn't seem to be any UI other than the notification every now and then.

I was planning to make an interface where you could snooze the notifications, change settings and refresh the player count manually in addition to the background service, so no need to tamper with any config files or source code

I'll probably collide with problems when I want to contact the background service with the foreground UI after the foreground part has been closed previously. Do you know if there's a command that would inquire if a spesific service is already in progress, so I wouldn't need to kill the old service and make a new one?

[OliVier_ Profile]

Yep i have used a convenience function that make the app compatible only with android >= 6 :/ There is a way to get the equivalent for all the version but it is also more work xD (laziness++)

Actually there is an UI defined in src/main/res/layout/activity_main.xml that kind of do what you describe.

Do you know if there's a command that would inquire if a spesific service is already in progress, so I wouldn't need to kill the old service and make a new one?

No need to worry about that startService() does the check for you

[RapidHail]

What if there would be a json or xml output instead of downloading whole site?

[GoldenBullet]

That would be convenient.
Are you planning of making such or is there already way to retrieve the server data in XML/JSON?