Detect the source of apk download - java

I have an apk file present in 2 standalone servers both of which have separate download links.
I would like to know if it is possible to detect from which link the apk was downloaded after the app was installed and opened.
The download is via browser and the one of the requirements is that the build has to remain the same.

If you are just installing your APK as a link directly on a file server, and the APKs are exactly the same, then no, there is no way to do this.
Here are some work-arounds:
Google Play provides a way for you to do this, but they are doing this through broadcasting an intent to the application after it has been successfully installed. You could release the APKs through Google Play privately through the beta / alpha channel, and take advantage of this feature perhaps. You'd not be able to use a private file server though.
You could create your own application that downloads and installs
the APKs and mimics Google Play's functionality which I described
above. This would probably be ridiculous for you to do, and I don't recommend it.
You could differentiate the APKs in some way. You could keep the content exactly the same, but configure some fields in the build logic through Gradle using the buildConfigField. You could also do split apks, use flavors, or a number of other different creative solutions if you wish.
So if for some reason the above suggestions don't meet your requirements, another solution that would be extremely hacky would be to use different APK file names. The browser would download the APK to the download folder, and you could probably look at the Android downloads folder after opening the app and look at the file name. This would not be reliable in any way though, as users could easily delete the file before actually opening your app, or there could be old downloads also. You'd have to look for base file names, and identify the most recent file based on creation date.

Related

java.lang.IllegalStateException: Not one of standard directories [duplicate]

Android Api 29 has big changes regarding files and folders.
I have not found a way so far to create a folder in the internal storage that is public visible.
Every folder I create can be seen by my app only.
I write an app that creates data files that shall be picked up by other apps, for instance the Total Commander to copy them to a destination.
Everything worked fine until I activated Api 29. Some of my clients DO use pixel phones and they use Android 10.
How can I create a folder and files in Android 10 that are public?
This has been deprecated:
Environment.getExternalStorageDirectory();
Environment.getExternalStoragePublicDirectory(type);
and when I use
File root = context.getExternalFilesDir(null);
The created files can only be seen by my app.
How can I achieve the behavior that was valid before Android 10?
Thanks in advance.
when I use File root = context.getExternalFilesDir(null); The created files can only be seen by my app
They can be seen by any app that uses the Storage Access Framework (e.g., ACTION_OPEN_DOCUMENT), if the user chooses the document that you place in that directory.
I write an app that creates data files that shall be picked up by other apps
Other apps have no access to external or removable storage on Android 10, except in the limited directories like getExternalFilesDir() or via non-filesystem means (ACTION_OPEN_DOCUMENT, MediaStore).
How can I create a folder and files in Android 10 that are public?
Use getExternalFilesDir() and related methods on Context. Or, use ACTION_CREATE_DOCUMENT or ACTION_OPEN_DOCUMENT_TREE and use the Storage Access Framework. In either case, the resulting documents can be used by other apps that also use the Storage Access Framework.
Starting from Android 10, you should use SAF, and let user choose the directory using ACTION_OPEN_DOCUMENT_TREE.
If you need a simple example. You can find it here
Alternatively, you could use requestLegacyExternalStorage = true in manifest when your app is not newly released. But, this is something that should not be used for future release, as this is a short-term solution provided by Google.
Note: In future releases of Android, user will not be able to pick the whole external file directory and Downloads directory, so unfortunately, keep in mind that we are not going to have access to these as well! For more information you can click here

Android APK with large resource files

I am developing OCR application and it has large size of resources which are copy from Computer directory into app folder using gradle build file. But it is generating very large size apk when im generating apk. What is the workaround I have to do for testing purpose when I install apk manually on my device through file storage and later for google play store.
The way you formatted your question, the answers you will get will be opinion based.
IMO:
During Developement:
Transfer the recourses you need from your pc to the device's external storage. (I.E. in downloads folder or something similar. I am not talking about any SD here.). This will be a time saver as you won't need to transfer these files everytime you build and re-run your app.
During Production:
I would suggest to not include the resources in your apk at all to achieve a small app size. Have the recourses reside on some server and implement some logic where the user downloads only what he needs when/if he needs it.

Updating an Andriod-Mobile Application

Is there a way to update my published app's first version if I have lost my signed apk, keystore and .pepk files? My laptop crashed - my data was not backed up. The only thing I have is that 1.aab file from Google play - I don't know how can it be helpful in my case.What can I do?
If it's published you can download the apk in the Google Play Console. APK extraction tools are there, as well as (dex2jar), what you'd have to do is rename file to zip, extract the contents, use dex2jar, change bundle ID/version or whatever in the manifest, resign it, then repackage the APK.
Those are the gist of it, high overview steps, you can easily find a detailed version on the internet or on SO if you look deeper.
You can use google console to recreate your signing stuff, keys, etc.
No, there is no chance to do that. You just learned how important a backup can be.

Expansion Files - Copying and Using

I have been looking at a few different tutorials, however am really struggling to see exactly how the Expansion Files can be firstly copied to a location that the user cannot access adn the how to use them in my actual app.
I will have a lot of key images within the Expansion file and therefore would also need to prevent users from playing the game until everything is downloaded.
Finally, I would have to also access a density based section for a lot of the images, along with a handful of raw files such as videos, this is what I currently have to work out which folder to open within the extension files.
String ExpansionFolder = "";
switch (getResources().getDisplayMetrics().densityDpi)
{
case DisplayMetrics.DENSITY_MEDIUM:
ExpansionFolder = "mdpi";
break;
case DisplayMetrics.DENSITY_HIGH:
ExpansionFolder = "hdpi";
break;
default: // This cover XHDPI, XXHDPI, TVDPI
ExpansionFolder = "xhdpi";
break;
}
Some sample code that i can use would be much appreciated.
I don't have sample code, because i haven't used expansion files myself, but specific answers to your questions do seem to be available at Android Developer APK Expansion Files page.
how the Expansion Files can be firstly copied to a location that the user cannot access adn the how to use them in my actual app.
from the "Storag Location" section of the Android developer page on expansion files (APK Expansion Files):
When Google Play downloads your expansion files to a device, it saves them to the system's shared storage location. To ensure proper behavior, you must not delete, move, or rename the expansion files. In the event that your application must perform the download from Google Play itself, you must save the files to the exact same location.
The specific location for your expansion files is:
[shared-storage]/Android/obb//
[shared-storage] is the path to the shared storage space, available from getExternalStorageDirectory().
[package-name] is your application's Java-style package name, available from getPackageName().
For each application, there are never more than two expansion files in this directory. One is the main expansion file and the other is the patch expansion file (if necessary). Previous versions are overwritten when you update your application with new expansion files.
If you must unpack the contents of your expansion files, do not delete the .obb expansion files afterwards and do not save the unpacked data in the same directory. You should save your unpacked files in the directory specified by getExternalFilesDir(). However, if possible, it's best if you use an expansion file format that allows you to read directly from the file instead of requiring you to unpack the data. For example, we've provided a library project called the APK Expansion Zip Library that reads your data directly from the ZIP file.
Note: Unlike APK files, any files saved on the shared storage can be read by the user and other applications.
From http://developer.android.com/reference/android/content/Context.html#getExternalFilesDir(java.lang.String):
getExternalFilesDir
Returns the absolute path to the directory on the primary external filesystem (that is somewhere on Environment.getExternalStorageDirectory()) where the application can place persistent files it owns. These files are internal to the applications, and not typically visible to the user as media.
I will have a lot of key images within the Expansion file and therefore would also need to prevent users from playing the game until everything is downloaded.
From the "Downloading the Expansion Files" section of APK Expansion Files:
In most cases, Google Play downloads and saves your expansion files to the device at the same time it installs or updates the APK. This way, the expansion files are available when your application launches for the first time. However, in some cases your app must download the expansion files itself by requesting them from a URL provided to you in a response from Google Play's Application Licensing service.
The basic logic you need to download your expansion files is the following:
When your application starts, look for the expansion files on the shared storage location (in the Android/obb/[package-name]/ directory).
If the expansion files are there, you're all set and your application can continue.
If the expansion files are not there:
a. Perform a request using Google Play's Application Licensing to get your app's expansion file names, sizes, and URLs.
b. Use the URLs provided by Google Play to download the expansion files and save the expansion files. You must save the files to the shared storage location (Android/obb/[package-name]/) and use the exact file name provided by Google Play's response.
Note: The URL that Google Play provides for your expansion files is unique for every download and each one expires shortly after it is given to your application.
In addition to the LVL, you need a set of code that downloads the expansion files over an HTTP connection and saves them to the proper location on the device's shared storage. As you build this procedure into your application, there are several issues you should take into consideration:
The device might not have enough space for the expansion files, so you should check before beginning the download and warn the user if there's not enough space.
File downloads should occur in a background service in order to avoid blocking the user interaction and allow the user to leave your app while the download completes.
A variety of errors might occur during the request and download that you must gracefully handle.
Network connectivity can change during the download, so you should handle such changes and if interrupted, resume the download when possible.
While the download occurs in the background, you should provide a notification that indicates the download progress, notifies the user when it's done, and takes the user back to your application when selected.
To simplify this work for you, we've built the Downloader Library, which requests the expansion file URLs through the licensing service, downloads the expansion files, performs all of the tasks listed above, and even allows your activity to pause and resume the download. By adding the Downloader Library and a few code hooks to your application, almost all the work to download the expansion files is already coded for you. As such, in order to provide the best user experience with minimal effort on your behalf, we recommend you use the Downloader Library to download your expansion files. The information in the following sections explain how to integrate the library into your application.
You may also find Steps to create APK expansion file useful, if you haven't already seen it, though I don't know if Google has changed anything regarding expansion files since that question and its answers were posted.

get uploaded file path in java web application

Since from the 4 days i have been trying to find out the path for the uploaded file. I think it wont possible. Can any one tell me how to get the uploaded file path in java web application. Is there any external API to get the uploaded file path? And my project is google app engine type project. Please some one answer it.
As you can't write to the file system it's likely you can't do whatever it is you are trying to do. So you need to use one of the storage options available instead, likely GCS.
https://developers.google.com/appengine/docs/java/googlecloudstorageclient/
Google Cloud Storage is useful for storing and serving large files.
Additionally, Cloud Storage offers the use of access control lists
(ACLs), and the ability to resume upload operations if they're
interrupted, and many other features. (The GCS client library makes
use of this resume capability automatically for your app, providing
you with a robust way to stream data into GCS.)

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