I have an IRC bot written entirely in Java that I've been hosting on my home computer, but my iffy internet connection has been disconnecting it a lot. I've been wondering if I could use the Google Apps Engine to host the bot with a constant connection? If so, what kind of changes am I going to have to make?
Thanks for the help
No, you cannot do that. Google App Engine does not allow arbitrary outgoing Socket connections (probably because they do not want people using their platform as a proxy server). The closest thing they offer is the URL Fetch API for accessing external content over the network/Internet.
Using that, you might be able to come up with something that drives an existing web-based IRC client using an App Engine app. Though I'm not sure what benefit that would have over just using a web-based IRC client directly.
Also you cannot have a "constant connection" to (or from) an App Engine app. The platform will automatically time-out/close any request that has not completed processing within about 30 seconds or so.
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After a lot of research i am more confused then before on what kind of server to use for an android app.
My question in a nutshell is: which kind of server is easier to use and deploy.
I want to create an android application that communicates with a server to find other clients, the server uses GCM to notify other clients that one client wants to communicate and is used to exchange the address of the clients. Afterwards the clients should be able to communicate directly to one another.
What i found out is that from the android point of view either would be fine, both is likewise possible and neither produces more work then the other.
On the server side it looks like web service would be better to use, because it is easier to find a server provider. I might be wrong here but it looks like most large server providers don't like to give you enough access to run a jar file.
Google and amazon offer servers that can host web services, i am not sure if a socket server would be possible there, so if anyone can give me some tips on good and affordable server providers i would also like to have some insight there.
I have a very basic design of my entire application, where several users with my app on there android devices commits data to the server (I have used REST web services(java) + postgresql as my server) through HTTP post request from the android application. I am successful in achieving this and app runs absolutely fine. Now i want to implement a scenario where any change(CRUD operations) on my db on server should create a notification on my users android device. How should i achieve this with my server design unchanged? I have looked into Google Cloud Messaging, but could figure out the server implementation.
For now i have implemented db triggers on postgresql and able to get control back into java code using Notify/Listen feature of postgresql. From here i need to connect to android device. How can this be achieved. Is Google Cloud Messaging the only way? I have not seen any insert/update statements in there server implementation. Could anyone please guide me on this?
either you can use GCM or implement a Socket at server end and open a socket connection from mobile but this approach may add some additional processing overhead because it will create a daemon thread to listen socket port from mobile device.
You should use native library (NotificationManager etc.), here you can find a great tutorial.
My Advice is for you to use GCM. GCM normally takes a maximum of 4kb, so you could have your own defined "commands". You could use them to determine the requests on both ends, ie on android app and the server end. A php script on the server would help you in this.
I am working on an app where by the android app sends messages to the server via POST and the server forwards the message to the appropriate user via GCM. In my case I have very many things to share so in that case I am using commands, for example if it is a new incoming message I send a GCM to the app with one variable as the command and the rest as the data. On the android app I use the command variable to determine what to do with the data.
Kindly avoid that socket advice, it will have your app drain the battery to sustain the open socket , besides you don't have to re-invent the wheel while Google servers already has it
I want to have a Java-Application that is behind a firewall (maybe even connected over a 3G modem) and I have a google app-engine application.
How can the gae app push data to the clients?
I found some ways that look promising, but I'm not sure what will really work.
Sockets will not work, because I cannot connect through the firewall/3G barrier
the channel API only works with JS clients
XMPP looks very promising - the client would report it's presence and the server could push chat-messages to the client and also the client could reply that way.
But what about user-accounts? i.e. could I use a single XMPP-account for all users (and let the client send a unique ID to identify the user) - or is a unique XMPP account for every device (which runs the java-aplication behind the firewall) required?
are there any other options or are there some XMPP gotcha's you know about?
I built an Android application with Google App Engine Server. Now I want to add simple chat to my app. And I have some questions.
My users registered with theirs desired email domains like hotmail.com, yahoo.com and even more esoteric domains, thats mean that I need to create JID for them? if so is Google App engine provide JID creations with my app domain that i can manipulate?
I read that Google App Engine act as XMPP client so I need Xmpp Server that can receive and send XMPP messages. So why do I GAE for? is Openfire is my answer? can I integrate Openfire with GAE?
I Also read that if I want to use XMPP in GAE and Android in need aSmack Api for my client and that it is working on HTTP. So I guess that I'll need to poll the server for messages every couple seconds. Is there a better pattern?
can I integrate Openfire with GAE?
You cannot run Openfire on GAE because GAE works only on HTTP so you won't be able to connect over sockets as Openfire does.
My users registered with theirs desired email domains like hotmail.com, yahoo.com and even more esoteric domains, thats mean that I need to create JID for them? if so is Google App engine provide JID creations with my app domain that i can manipulate?
If I understand your question correctly, you shouldn't have any problems here. As long as you're not a spammer, we don't place any restrictions on what domains you can send to.
I read that Google App Engine act as XMPP client so I need Xmpp Server that can receive and send XMPP messages. So why do I GAE for? is Openfire is my answer? can I integrate Openfire with GAE?
You can send and receive XMPP messages via the xmpp API (this is the python version). This calls into the Google Talk infrastructure. You don't have access to what you'd traditionally call an "XMPP server", but you do have access to basic XMPP functionality.
I don't know a lot about OpenFire, but there is a Trusted Tester program for outbound sockets that you can sign up for. This is what you would need if you desire an external XMPP server.
I Also read that if I want to use XMPP in GAE and Android in need aSmack Api for my client and that it is working on HTTP. So I guess that I'll need to poll the server for messages every couple seconds. Is there a better pattern?
I should prefix this by saying I don't know a whole lot about Android or aSmack, but that won't stop me from taking a stab at answering your question. :-)
I think this depends on your usecase, but I can't think of any situation you'd need to do this off the top of my head. Will the user of your application have their own JID on a server they registered for? If so, I don't see any reason you'd have to connect via HTTP, unless that's all aSmack supports. The main use-case for BOSH/XMPP-over-HTTP is in the browser where you don't really have access to open raw sockets.
If you want to use XMPP as a messaging/notification service the user won't know about, it may be more complex. I should note that you can always set up an XMPP server on Google Compute Engine.
A friend and I are currently working on a turn-based game with chat with both desktop browser and Android clients, with Google App Engine as the server.
We're using the Java API for GAE and using HTTP for communication with the server. We've implemented simple chat functionality, and we're getting undesirable latencies 1-3 seconds from both the browser and Android clients while just posting simple one-word chat messages.
My friend thought it would be best to use XMPP instead of HTTP, but we want to use a Google Accounts cookie for authentication from the Android client, and according to the GAE documentation, XMPP clients cannot use a Google Accounts cookie and must use the user's password.
Does anyone have any suggestions as to where the latency might be coming from, how to troubleshoot it, and/or what to do about it?
Also, is anyone aware of any opensource implementations of chat (or something similar) on GAE done in Java? Can't seem to find any.
One way to analyze the situation would be to use Wireshark to look at the network traffic during the delays.
You don't say how your chat messages are getting from one JVM to the other. If you're using the datastore, maybe try memcache?
Also, startup time is often an issue; app engine starts and stops JVMs all the time, particularly for a low-traffic app. A way to diagnose this is to reload the page a bunch of times (send more messages) and see if it gets faster after a while. It should be pretty easy to tell the difference in the admin console logs.