I have an app that has an activity which allow users to download PDF files by selecting a PDF and clicking the download button.
The issue is: I don't want to always ask users to update the app when there's a new material available.
Is there a way I can update the .java code without always asking users to update the app?
Wrong design point.
You have probably hardcoded the PDF / file names in your Java application.
When these values are supposed to change, then well: don't hardcode them.
Instead you create a server side service that lists the available PDFs. And then your app uses that service in order to acquire that information.
Anything that is "dynamic" must not be hardcoded in your app itself. Instead your app knows how to fetch that piece of information from somewhere.
When the source code of your application changes, your users have to upgrade the app. It is that simple. The other way round: if you know about "changes" to your app that need to work without upgrading the app, then well: you have to design the whole app around that requirement.
A first starting point / further reading: see here.
I have created an Android application in which it is able to read files from the Google Drive Hidden AppData folder and react based on whether specific filenames are present.
I have created a separate external interface that creates a file in this folder and it seems to do it successfully.
The problem I have is that I can't seem to find a work around for having my android application constantly listening/receiving updates from the appdata folder.
The odd thing is, is that sometimes the application will pick up the file change straight away but other times it can take hours.
I'm convinced that Google's 'OnChangeSubscription' method they provide in the developer documentation doesn't actually work.
Any suggestions on methods I could try/where people have been successful at this would be great as I have been at it for weeks and it's the final thing I have left to do.
Is it possible to get the user behavior on the phone (for example Alpesh has an Android phone and he uses multiple apps, browser YouTube etc). Whatever he is doing on the phone I want to get all those things from behind (which apps he has installed, which app he opens and what he search on the phone, All these data I want to get programmatically so what all can be get in android).
For now I am aware that installed apps list can be get easily but I want to get usage history and what he do all on mobile.
This is not a code solution, but an answer to your question, so you can get start some where.
In my opinion your question title are asking about two things.
(part 1) Getting User Behavior on the Android Phone (part 2)(App History, Browse
History etc)
1- First part Getting User Behavior on the Android Phone:
There is a concept called context awareness. Short described; it is about gathering different information from the phone, like light sensor, motion sensor, sound, location or even user behavior etc. and depending on your app requirement and the gathered information:
You could send these information over cloud data store for statically usage
You could make your phone doing (behavior) different things depending on location, motion or what ever.
etc.
For context awareness it is an open area for pervasive computing research. And it is not just few lines of code to write, it is typically a complete solution depending on requirement. Example I have built a context awareness application to gather noise collected by phones from different locations for research purpose inspired from this framework, but I am pretty sure you can find other frameworks or even build your own, as I did in my case.
The mentioned framework has some examples.
2- The second part is about App History, Browse History etc.:
This is possible, but you still need to build a peace of software (App) to collect all these information (logs) from the phone. Hereafter you can make phone act on different conditions and/or again send it over a RESTful API over cloud service data store, there is no limit for it.
The problem is, there is no thing out of the box for your requirement. Even if you find frameworks you still need to research it and further work on it.
You can find different examples for your requirement, like to collect browser history, you can find SO question here:
Get browser history and search result in android
Or get list of installed application:
How to get a list of installed android applications and pick one to run
My point here is you need to solve small goals at a time and put your knowledge together at the end.
Both 1 and 2 can also be related to each other, depending on your achievement.
Conclusion
Make a goal to your project.
Define the main requirements and tasks of your project.
Research your options (Technology, Cost, Target Audience, What data I can or I should not collect, what is possible to collect, what is the limits, Privacy issues etc.).
Split your project in small assets and try to solve small problems/goals.
Finally you would be able to put the puzzles together and build your final application
but i want to get usage history and what he do all on mobile
This is not possible and shouldn't ever be possible. Each app is sandboxed by Android so apps cannot inspect what other apps are doing. Think about it, you wouldn't want apps to be able to intercept private information such as banking details.
Every app is isolated from the other ones. Unless you develop a system signed app, you will not be able to gather all that data.
What you could do is to develop your own Android Rom where you then develop your data collection the exact way you want. Then you need to distribute your rom, which is another story...
I am new to android programming, I have developed 2 very simple apps, one is a weather and other is a story app.
I am planning to develop a app similar to photo vault app.
Similar to this - https://play.google.com/store/apps/details?id=com.enchantedcloud.photovault&hl=en
How complex is this? I am not able to find much information online to develop the app. Is there any way to copy over the files in the photo camera library to a new location and then hide them?
The app should basically do this:
1) Ask for a password, when user opens app. --> Easy DONE
2) Ask user permission to access the camera photo library --> Stuck :(
3) Let user select the pics he wants to copy and hide in the app --> Stuck :(
4) Copy these pics in a secret location? or encrypt them? --> Stuck need help here.
5) Save them and when the user needs access to them, ask for a pass and show them.
I am not planning to support videos yet, just hiding jpegs is good enough.
Any help would be appreciated. Thanks guys.
I have small hack over here. Try to get apk file of the above application and use Java decompiler(Kind of reverese Engineering) Java Decomplier to check what all java files how he organised it and what structure he followed and I am not sure that will decompile resource files even(xml) files. Hope it helps you a bit.
Want to create a simple app that runs locally whatever on PC or mobile devices, which shows various products information which would be loaded from local file system (documents, videos, htmls and so on). Furthermore it's able to configured later on.(change source directories, change button label.)
Please suggest what framework is well suited for developing this kind of application. Thanks.