I want to keep a connection alive to my Android application so that when the server wishes to communicate to the device (ie. send new data) to be able to do so. I do not want to use external API's or requests from the mobile; just a connection that stays idle until I send data from my server. What would be the simple way to go with this?
If you only need to keep the connection alive when your app is running, do the following:
If your application makes constant use of the network, it's probably
most efficient to set up a single instance of RequestQueue that will
last the lifetime of your app.
From here: https://developer.android.com/training/volley/requestqueue.html
Otherwise, Google Cloud Messaging is the right approach: https://developer.android.com/google/gcm/index.html
Maybe look into Google Cloud Messaging for Android, see the overview page here
Related
If I open a web app using a web browser or a PWA by clicking the icon on my home screen, can that app still send HTTP requests while it's minimized?
I'm asking this because of say, for example, I want to check out a navigation app to navigate to somewhere but I still want the web app to update the user's location through HTTP requests while it's minimized.
Is it possible or does the app stop "working" while it's not in focus? Is it a service worker implementation needed?
You can achieve your task implementing a PWA. The Service Worker file will run in the background and keep running even when the user closes the app.
This is possible since the SW runs on a separate thread.
It is also possible to execute background sync, even though its support is quite limited:
You can let the service worker call the server to send the user's position if internet connection is available, otherwise this information can be stored in a local DB (eg. IndexedDB or Cloud Firestore) and then, once the users gets online again, the changes will be pushed to the server.
The nice thing by using Cloud Firestore is that the synchronisation is made out of the box for you. I wrote an article about the usage of Firestore with PWAs to overcome the limits of CACHE API. It is within a series of articles about PWAs, have a look st tit if you want to deepen the topic.
I started with a application where you can chat.
Now im in the position to start with the chat.
The problem I'm facing is that I don't want to use
resources from "outside". With outside I mean:
Firebase, Socket.io and so on.
I do simply rent a webspace. And I'm asking you now,
how is it possible to realize an live chat without
using extern services like firebase.
Is it possible with only using an Webspace?
What is required to make an live chat?
And there comes the second question:
How do I realize to stay connected to a server to check if there is a new message without using much battery or network ressources?
I'm not asking without hardly trying by my self.
Two days ago I started with the research of possibility, but I didn't found anything which would work I guess.
Thanks folks...
You need to connect to the Web Server using a Socket and keep that connection open to receive new messages with little delay (see for example http://srchea.com/build-a-real-time-application-using-html5-websockets) This keeps the phone active and uses much battery.
The very purpose of Firebase is to bundle this work for all services which need this type of communication (E-Mail, Push messages of newspapers, Chats) such that the phone only has to query one server. Therefore, I see no way for you to find another solution which uses little battery.
This may be duplicate question but am still having doubt am a beginner in android application i have a couple of doubts my primary doubt is:
I have made one application which will communicate with server when network available it will work as it is. when network is not available data will save in sqlite and later when network is avail need to sync that data to server how can i achieve this.
Whenever there is new update is made with server need to get notification how can i do this
For this one which will be the best approach syncadapter or server or intent service with broadcast receiver which would be opptimized solution for the above requirement
These are all my doubts i would be very glad if someone helps me !!!
If you want an Android app to be notified when something happens on a server you control (without having the app to constantly poll the server to ask for changes), the usual solution is to use Google Cloud Messaging to allow the server to send a notification to the app to tell it to refresh data.
It is kind of complicated to implement, but is the best way to do what you want and is standard practice for mobile apps.
If you need to know when the network becomes available, to reach your server for synchronization, implement connectivity change listener, as discussed in this question.
This does not allow to send messages from the server easily, but if the server messages are not of high urgency, maybe you can simply check for them periodically.
This would allow to use less Google specific infrastructure and change the cloud providers easier.
I'm try to make my Android App that send an HTTPRequest to a server repeatedly even when the App is not running (much like chat).The server will return a JSON file and if there is any update at the file, the app will send a notification to the user.
How can I do that?
Thnks.
From you question i can only understand that you are polling from server. Repeated hit will drain your battery very fast and will exploit user bandwidth also. With this kind of mechanism there are changes that your app will be uninstalled very soon.
So, what i will suggest use push notification ,if there is any update let server tell you. There is no need for client to ask for it.
One more way but complicated both at server and client side is you can open your own TCP socket and can then you can share as much data in both direction.
I can suggest you to go with push-notification for easy implementation and do right thing.
You have to use Service as explain here :
http://developer.android.com/reference/android/app/Service.html
Only service could run in background when Activity are not visible.
I need to open and keep long term connection with server to send messages, recieve response. Also sometimes server sends information without user request, so android device should listen to the server and react.
There are AsyncTasks, where I can implement socket connection, but main problem is that I know only one way - to send request and recieve response once. Then AsyncTask (and connection) is closed.
I have also read about services (that I never used).
Is it possible to make long term (1-4 hours) connection with server that keeps connection alive, listens for user commands (for example, need to send data to server when button is clicked) and recieves response or requests from server (and then changes UI).
Will service (and connection) be killed when phone fall asleep, needs more memmory or other? Is it big cost to the battery?
Maybe there are other ways? Thank you in advance for all your answers
P.S. sorry for poor english skills, hope you understood :)
You should probably use a Service, running in background.
Also, you really need not keep the service always alive with a network connection. You can opt for Google Cloud Messaging, which supports 2-way communication via the XMPP protocol. Using this protocol you can:
Receive notifications from server, start the service and do necessary processing.
Send notifications to server, upon which server does any necessary work.
These notifications are short 4kb messages , so they are better used as "commands" of a publish/subscribe model, which initiate other network heavy connections such as uploads and downloads. Rest of the time the service can be inactive to reduce resources consumption.
According to Android API Reference
"A Service is an application component that can perform long-running operations in the background"
And yes it consumes battery and you have to stop it by yourself:
" It's important that your application stops its services when it's done working, to avoid wasting system resources and consuming battery power"
So I think Services fit your needs.
If you need to communicate with the server when you want to send data to the server you can do it and wait for answer. If you need to send data from server to the device then take a look at push notifications.