I have an Android application as part of a degree project that is based on music matching.
The application controls spotify using the spotify SDK, and receives information using the web api.
As part of the project, I need to implement a recommendation algorithm based on data from certain columns in a CSV file, I have a database.csv file of a million Spotify songs and I am supposed to send certain parameters and the CSV file to the algorithm and it will find the most suitable songs for me from the CSV file (return their IDs to me).
I was not able to understand how it is possible to run the algorithm in real time from within the application assuming that the file itself cannot be saved locally.
What possible technologies allow me to save the file in a "remote" location and receive from it the output of the algorithm to my application?
(I think if it exists then there is an API that provides it)
Related
My company has three different Android apps that provide functionality for sales reps. We opted to separate the apps into "modules" because not all reps need all the modules. Up to now we have been using a JSON file in a directory on the SD card of the devices to set some configuration data for the apps. However, it appears that with Android 10 and beyond this will no longer be possible.
Currently we use getExternalStorageDirectory() to access the SDCARD and then open a file inside a directory our app creates.
Since we want the file access to not be something the sales reps have any control over we want it to happen transparently. However it does not seem this will be possible going forward.
Will using a custom FileProvider or even a DocumentsProvider be a way to continue to share data between our apps?
Another question, although not as important, is, can we change the default location of the DB files our app creates as we do now in earlier versions of Android?
Thanks
Rich
i have developed a android app for farmers. it is a informative app for indian farmer.The users will be sending me the images and video files to me through my app. here i used (integrated) dropbox to receive those files directly to my dropbox space. whatever the image or video taken by the user, it will be stored on a folder in my mobile storage. Here what i want is, i want the folder in my mobile storage to be in sync with the folder in my dropbox.
How can i do this?
there is a app in market called Foldersync which exactly fulfil my requirement. how they are doing it? How can i keep a folder in my mobile storage and a folder in my dropbox to be in Sync?
Note :
i have gone through drop-box api and created a simple app to send files directly to my dropbox space and i know how to download a entire folder from dropbox.
But here my question is unique from that... pls don't answer the above points which i already know..
Please help!
Thank You
You can use the Dropbox API to keep a local client in sync with Dropbox. There are two main pieces to this:
1) Metadata:
Assuming you're using the Core API, the best way to get information about all of the file and folders in an account (or optionally under a specific path) is to use /delta:
https://www.dropbox.com/developers/core/docs#delta
With this, you can get information about everything your app can see, and then easily stay up to date with changes. There are some useful blog posts on using /delta here:
https://blogs.dropbox.com/developers/2013/12/efficiently-enumerating-dropbox-with-delta/
https://blogs.dropbox.com/developers/2013/12/filtering-dropbox-delta-results-by-path/
2) File content:
Using the metadata retrieved from #1, you can download any files you need access to locally using /files (GET):
https://www.dropbox.com/developers/core/docs#files-GET
You can upload locally changed files using /files_put:
https://www.dropbox.com/developers/core/docs#files_put
Or, for larger files, use chunked uploading:
https://www.dropbox.com/developers/core/docs#chunked-upload
https://www.dropbox.com/developers/core/docs#commit-chunked-upload
The main work here will involve programming the logic in your app to correctly receive changes from the server as well as upload local changes, in order to keep everything in sync.
Also, be aware that on mobile devices, bandwidth can be limited and/or expensive, so be careful to not accidentally automatically download a lot of data the user doesn't want or need.
We had initially planned on developing a native app for Android but PhoneGap is looking like a better option.
One thing we need to have is when the user installs the app, they need to have local access to a sample of the data in our back end database but have it stored locally. On the native app we had planned that when the user installed the app, the installation process would also trigger a retrieval of a chunk of the data in the back end database so that they could make basic usage of the app without relying on an internet connection all the time.
This data will include JPG files and perhaps some audio files. Will HTML5's local storage address this requirement?
short answer: YES
That's what makes phonegap awesome, you may create a database in to store the persisting data details (name & path)
When you run your application, you will test the connection, if there is no connection you can refer to the local files through your database else if there is connection you may download the new data, save them to the local database and then delete them from the local storage (Sdcard & database).
to find more check the phonegap's file docs
Just to add to what T.Baba has said, yes it is very possible, and I have recently built a webapp with PhoneGap and jQuery Mobile that does just that.
I used localStorage to contain all the data, and in particular localstoragedb. I haven't stored any images and/or audio files in localStorage and wouldn't recommend it anyway as most devices will limit the space to 5MB, but PhoneGap does give you access to APIs which will allow you to save files on the user's device. You can also of course bundle the files with the app and access them accordingly.
Indeed it is. Phonegap is best option for that.
I have a simple application that should handle (display, play...) data downloaded by users. I.e. when the user downloads the application (for free), it is empty, or filled just with some sample data, but then the user can download the actual content of their preference (and potentially pay for it via Android billing system). Each item is a folder with an xml file plus several sub-folders (such as audio and images). In the development phase the data are stored in the assets directory.
The payment itself is not a subject of the question at this point. I am actually interested in the following:
where can I store the downloaded data in the phone so that it would be accessible for the application but so it could not be copied manually by the user (for example to another phone). It would be ideal if I could store the downloaded data in the assets directory but I'm afraid once the apk file is generated, assets are "locked" and cannot be easily extended (or can they?) If I store them on the phone's card (or in the built-in memory), they will be accessible by other applications such as media player or galleries, too, won't they?
it would be great if I could download the package as a single single file - is it possible to upack it by an built-in method and store it as a folder with upacked (and thus readable) sub-folders and files?
when the application is downloaded, it is an apk file. Therefore it should be possible to have the sample data (i.e. downloaded with the application) at the same location as the data that will be downloaded later. How can I ensure this.
the data can be pretty large and therefore it is not an option to have all of them included in the assets folder immediate after the download and unlock it on basis of the user's actions
once the data are downloaded, they must work off-line (i.e. the user must be able to display them without internet access; thus it is not possible to check identity of the user on the server - they can simply display anything they have previously downloaded)
Example (for clarification purposes): have an application able to display recipes. It does not contain any or just a few after installation. You should be able to download recipes (one by one) from a server (each having a certain file structure stored in a seperate directory). Once they are downloaded, they become an integral part of the application and always accessible for the user even if the use the airplane mode of their phone.
Hope it makes at least some sense (I can clarify the question further if it doesn't). I've found several tutorials on how to work with data stored in assets and on how to handle data on an sd card but none concerning this particular topic.
you may store your date in your application data folder, basically it's available to your application only. if you want to prevent your data to be copied to another phone, generate a random UUID on the first run, and then use it to encrypt your data stored in the data folder. another phone will have different UUID and different encryption key, making it pointless trying to copy encrypted data. you may even use non-symmetrical encryption and send your generated (public) key to the server and have the server to encode your data and send it back in encrypted form, thus preventing your data to be exposed at all.
the assets/ folder is generally read-only, you may put your data there only during the build step.
make your file a .zip file -- these are compact and you may easily read files and folders and whatever you need using java.util.zip.ZipFile
sample data goes into assets folder, you may copy it out to the data folder on the first run.
once you download the data and save it to the device, i don't see any reason why your application won't work offline
I am working on an app that connects to a media providing site and downloads mp3 files to the user phone. I would like for the user to be unable to copy these files off the phone but only listen to them through my app.
I am currently trying to encrypt the files using DES and encryption and decrypt and play the file in bits in the app. This is however not working. Is there a better way of achieving my end goal or has anyone else implemented a similar solution?
Thanks
P
If you use DES (a private key or symmetric-key algorithm) you need to store you the decryption key in your app. Remember this is Android's byte code, much easier to disassemble to retrieve key.
Think of other DRM alternatives.
If you use Android's internal storage, the file system you create can only be accessed by your app. However, due to the open nature of Android there are many "Rooted" android ROMs available that allow public access to these files.