I'm creating an app that connects via internet to a rest API which is connect to a postgres database.
In this API I am exporting some JSON data that I wish to consume using the app. I pretend on using okhttp3 to do this.
The thing is, I wan't this JSON data to be available locally, and be downloaded to the persons phone since the app is mostly going to be used underground, inside subway stations, where there is no internet connection.
My question is how can I get the data that return from the REST API, and persisti it to a JSON file and then deserialize it as needed to show the data to the user.
I pretend on using GSON to deserialize, but I don't know how to save the data to a file and, after that, acess that data.
Also I pretend on implementing a automatic update system where, after any change on the data, the app will be able to download and overwrite the old data with the updated version.
Also I'm using Java, not Kotlin, for this app.
Related
I want to update content/news in my app based on any online resource that's possible, a website, database or something similar where I can manually update/add content. The underlying purpose is to connect my app to that online resource, and reflect changes in my app content, whenever I update that online resource.
Right now I don't know what should be that online resource and how should I connect it with my app.
I would appreciate anyone coming up with any form of suggestions/solution.
Updating App Content means retrieving data which is stored on server in some database.
We can store and retrieve data or any content with the use of Web Services.
With the use of Web services you can parse the data and display it in your application.
You can also develop an Admin Panel for managing all your resources which will be then reflect to in your app.
These above things are possible using Networking libraries like OkHTTP, Volly, Retrofit etc. which gives you response in form of JSON (JavaScriptObjectNotation).
For Refrence Please visit :
OKHTTP > https://square.github.io/okhttp/
VOLLEY > https://developer.android.com/training/volley
RETROFIT > https://square.github.io/retrofit/
Lookup OkHttp library by Square. Super easy way to connect to an API. Then you can check out rapidapi website for a collection of APIs
If you have an Api endpoint you can use Retrofit to get data. However if you dont then i belive you will need to make server using php and then connect to that server using Volley/OkHttp3 in order to get data.
I have a HTTP server to respond to the rest requests from a mobile devices. Server data won't change frequently so I am thinking to store the data inside the devices. The data is read only for the users. So I am thinking to share the whole db with the devices as a file. If I update the db, I will create this file again. When user open the application, it will check for update time from the server. If there is an update, the device will download new file. I need to convert MySql db into the Android and IOS readable file. Protocol-buffers can easily read from the both platforms. Are there any way to dump MySql data into a protobuf. Or should I use a different mechanism?
I want to ask a question from my app users and get their answers but i don't know how to collect those data.
Please help me I need it.
You can use a form inside your application. And, ask users to fill that form. The forms needs to be connected to an database server. You may use 000webhost.com (free) to create your database. Just populate the table in database from the user response.
For this follow the following procedure:
1. Create a online database (000webhost.com)
2. Write php code to insert data into the database form and save that php on the file manager on server.
3. From android create a async task to execute that php.
4. Pass your parameter or user response as request attributes while executing the php.
5. php will save user's response on your server.
Now you can access that database from anywhere.
Note: This may require an internet connection in application.
Your question is much vague.
In general, app need to use HTTP POST with some standard data format as JSON/XML for communication between web server/client app.
This way client apps send/receive data in portable format across platforms &
implements UI/functionality as per platform standard e.g. Android or iOS
You could implement Google analytics in your app. Raise an event when you ask a question.
The android app stores the data in SQLite database during the offline mode. When online I want the app to sync (in both direction) with the datastore(database) in cloud server (App Engine). How do I implement this functionality, so that I can show the data captured on phone on a web application. Also please suggest any simple alternative way if any..
I just write out my data as a String (using a format I can reconstruct my data with), pass that to AE, parse it and store/display it.
You could use json too.
or try http://mylifewithandroid.blogspot.jp/2010/10/client-server-communication-with-json.html
for the sync part I use a timestamp. If the timestamped result isn't recorded on the server, I record it. I send back the recorded stamps to the client and delete them from the store. Of course the server can also send back new results if a user's records were updated from a different client.
In general, you should implement some complex algorithm, that will be doing synchronization depending on your needs, and then make it in code on both side (server and client). This not quite a simple task, in general. Useful keywords for googling: SOAP, REST, JSON, ...
I am creating an android application which records soccer scores.
I have an external mysql database created on my own host.
How do i retrieve the data from the database in order to display it in my application?
Thanks in advance!
You need to write a service hosted on your database using either php or some other language you are comfortable which exposes data as XML/JSON.
Android has HTTPURLConnection capability,using which you can query your service by passing the parameters. Your service queries database and consturcts data either as XML or JSON using libraries and returns to app.
Your app need to parse the response (if XML, using SAX/DOM or someother APIs, if JSON using Android in-buit json parser) and display. Here is an example on how to do.
If you also want to retrive the information to be used offline, you can create an empty database locally, and update it by passing SQL statements. This is not the most efficient way to do it, but it worked for me since I am not working with a huge db.
Otherwise, use HTTP connection connecting to your remote host and pass the result via JSON object.