Develop Reference

Android SDK for fingerprint matching - External device

I'm developing an Android application that uses U.are.U 4500 fingerprint reader to identify users. I already have a backend server, that uses SQL Server, to store and register user data and now I need my app to be able to read the user fingerprint and verify if this fingerprint matches any of the fingerprints on the database. Does anyone know a SDK that is able to do this comparison?
I'm using asia.kanopi.fingerscan package to read the user fingerprint and I already have the scan working, now I only need to get this image and compare to the data on the SQL database. I saw a few answers here on StackOverflow telling me to use openCV library for Android, but none of them could give me any lead on how to do it.
I based my development on this tutorial: https://medium.com/touch4it/fingerprint-external-scanner-with-usb-database-sdk-64c3ec5ea82d, but unfortunately I couldn't find the SDK IDKit Fingerprint SDK Mobile anywhere.
How can I sucessufully match the image with the one stored on the database?

For those who are still looking for an answer to this problem. It's been a while since I actually implemented my solution and, when I did it, I added this line to my app gradle file:
com.github.lmone:SourceAFIS-Android:v3.4.0-fix3
But now I can't seem to find the github link anywhere. Maybe the repository got deleted. If someone find it, please send it to me so I can update my answer here.
Besides that, if you can still add the library to your Android project, the basic idea is to use a FingerprintMatcher to compare two FingerprintTemplate.
Example:
FingerprintTemplate probe = new FingerprintTemplate().dpi(500).create(digital_byte_array);
while (result.next()) {
byte[] imgCandidate = digital_to_compare;
FingerprintTemplate candidate = new FingerprintTemplate()
.dpi(500)
.create(imgCandidate);
double score = new FingerprintMatcher()
.index(probe)
.match(candidate);
if (score >= 40) {
// Found a match
}
}
In my case, I found the performance a little slow. It was usable, but nothing compared to Android's built-in fingerprint device. Also, the bigger your digitals collection, the longer it will take to find a match.
The score of the match is up for you to decide what suits better your project. 40 was a reliable amount in my case. The same goes to the FingerprintTemplate dpi.
Also, the method .create() receives a byte[] as parameter.
EDIT
I found this link and I'm almost certain it is the library I used, but under a new repository name:
https://github.com/robertvazan/sourceafis-java
The docs looks just the same as the code I used: https://sourceafis.machinezoo.com/java

To match a user on server side, you have to use an AFIS server : https://en.wikipedia.org/wiki/Integrated_Automated_Fingerprint_Identification_System
Here some providers of AFIS solution:
http://www.neurotechnology.com/megamatcher.html
https://www.nec.com.au/expertise/safety-security/identity-access/fingerprint
https://www.innovatrics.com/innovatrics-abis/
https://www.dermalog.com/products/software/civil-afis-abis/
http://www.m2sys.com/automated-fingerprint-identification-system-afis/

Can't get OpenFL URLLoader to work on Android (works fine with Haxe/Neko)

I have an Android app that I've written in Haxe that uses openfl.net.URLLoader to fetch the JSON for an array (it's a game and the high scores are stored on a web server). I'm using FlashDevelop 5.1.1.1 for the IDE.
When I compile the app to Neko it runs fine and gets the JSON string from the webserver no problem.
When I compile to Android and install it on my phone, it never contacts the webserver. I have the webserver notify me when any page is loaded, so I know the server is never being reached at all by the Android app.
The app has the INTERNET permission, as specified in the Project.xml:
That's really redundant though since I'm also using the In-App Purchase extension for openfl (extension.iap.IAP), which automatically adds the INTERNET permission (and works just fine).
For completeness, here's the code:
var urll:URLLoader = new openfl.net.URLLoader();
urll.addEventListener(Event.COMPLETE, function(e:Event){
// Parses JSON result here -- this code is never reached.
}
urll.load(new URLRequest("http://example.com/?action=highscores"));
I also tried to use haxe.Http.requestUrl, which works perfectly in Neko, I get an "invalid socket handle" error.
Any ideas about what I'm missing? Again, works perfectly in Neko, fails to fetch the page on Android.
Thanks in advance!

What if instead of local variable var urll:URLLoader use class member, and remove anonymous function?
Or as alternative use haxe.Http

How to delete data in tempDirectory on app restart/shutdown - Appcelerator Titanium

Part of my app functionalities is allowing user to multi select photos from gallery and then upload them. Before uploading, user is free to add/delete their photos.
What I'm doing is I create and store these temporary image files in Titanium.Filesystem.tempDirectory, with an intention that these will be deleted eventually on app restart or shutdown.
Though, when I use Finder to track these files, they're still there and do not get deleted after I close and reopen the app/reboot ios simulator.
So do I have to explicitly delete these files? Does the actual ios device behave any differently?
Thank you
Simply the codes where these img files get created:
var f = Titanium.Filesystem.getFile(Titanium.Filesystem.tempDirectory, fileName);
if (f.write(imageBlob) === false) {
console.log("Image writing failed");
}

You can just leave the files there. On a device they will be cleaned up when the device needs space.

Cordova / Phonegap: Live update codebase

We are using Cordova along with AngularJS for iOS and Android applications.
One big disadvantage of iOS are the long review times from Apple. In Google's Playstore, your app is available nearly immediately, or within a few hours. But Apple takes ages to review your app, even when it's only a small change.
So I was thinking, if there is a way to support some kind of live update.
That means, I could provide a ZIP file or something else with a new codebase, my app checks for updates and then installs the new files.
I've read something from appmobi, but are there any open source solutions?

cordova-app-loader is an easy to use plugin to update app files via 3 simple steps:
check() for a new manifest
download() files
update() your app!
It supports android and iOS

I don't know of any ready made solutions for that, but it should be easy enough to program something like this on your own.
Here are some points to get you started and to consider:
If you want to distribute updates via zip, you need a nativ plugin which handles the extraction
You might not be able to override files in the default location of your app (depending on OS). So, all files you want to update in the future have to sit in a folder your app has read/write access to (iOS: e.g. Library or Documents folder)
Now you simply need to download the zip-package, unpack the zip to your chosen directory, and restart/reload your app.
you will not be able to update native plugins!
Apple probably doesn't like that, since you are able to change the whole application without passing
their review process

I'm doing this inside my cordova app and haven't had any issues with ios app store review.
I'm using Jquery's ajax function to download both a javascript and a css file from a server that I can change without an app store approval and then I can inject those scripts once they downloaded on app startup.
I tried using the cordova File api and I'd then save the file locally, but offline support ins't the important to me at the moment and Jquery's ajax is much simpler.
Here is the jquery code I use. I have a bundle id that I use to detect if a new javascript file is available, otherwise jquery's ajax caches the previous requests to speed up download time.
This solution lets you have a subset of your code be dynamic. I still have a base set of code that is bundled with the app, along with native plugin js and native code which would need to go through the app store. But this atleast lets me push bug fixes without going through the app store.
Otherwise, I'd look at a solution like this: http://docs.build.phonegap.com/en_US/tools_hydration.md.html
function insertScript(version) {
var scriptUrl = "";
try {
// get javascript file...
scriptUrl = mobileWebServiceUrl + "/DynamicContent/Bundles/Scripts/dynamic";
scriptUrl += "_" + bundleVersion.replace(/\./g, "_") + ".js?v=" + version;
console.log("downloading script: " + scriptUrl);
// Allow user to set any option except for dataType, cache, and url
options = {
dataType: "script",
cache: true,
url: scriptUrl
};
// Use $.ajax() since it is more flexible than $.getScript
// Return the jqXHR object so we can chain callbacks
return $.ajax(options).success(function(response) {
console.log("insertScript success");
dynamicContentScriptLoaded = true;
});
} catch (e) {
//console.error(e);
ReportError("problem downloading javscript: " + scriptUrl);
}
}
function insertCSS(version) {
try {
// get css file...
var cssUrl = mobileWebServiceUrl + "/DynamicContent/Bundles/Css/dynamic";
cssUrl += "_" + bundleVersion.replace(/\./g, "_") + ".css?v=" + version;
console.log("downloading dynamic css: " + cssUrl);
$.ajax(cssUrl)
.success(function (response) {
console.log("successfully downloaded dynamic css");
var script = document.createElement("style");
script.type = "text/css";
script.innerHTML = response;
$('head link').each(function () {
if ($(this).attr('href').search('MobileFrame') > -1) {
$("#MobileFrameCSS").before(script);
}
});
dynamicContentCssLoaded = true;
// TODO: implement caching at a later date
//if (isPhoneGap())
// saveFile("DynamicStyles", response);
});
} catch (e) {
ReportError("problem downloading css");
}
}

Well, Adobe offers exactly that service in their Phonegap Build service. It's called Hydration.
The example shows using it with Android and iOS platforms, so I guess they made it compatible with the iOS Dev Program License Agreement.
If you are using Cordova, you probably will have to switch to the Phonegap CLI if you want to use their build cloud services, which is basically the same as Cordova's with some extra commands to upload to their cloud, etc.
I think there are some plugin like Splashscreen wich also have some minor changes (using <gap>for params into config.xml instead of <preference>). Again, if Hydration solves the problem for you, the changes are minor and you get a really nice feature.

I think the best choice would be to not try to do this with Phonegap, but rather identify your dynamic parts and implement these in Javascript.
Yes, I mean you should indeed use Javascript yourself without Phonegap, for example via JavaScriptBridge:
https://github.com/kishikawakatsumi/JavaScriptBridge
It may require more work initially to redesign your app into a "static" part (your PhoneGap app) and dynamic part (dynamic created views via JavascriptBirdge), and interacte seemlessly between them. But in my opinion, that will be ultimately the best software design.
However, also make sure you still meet Apples AppStore requirements.

The Meteor framework provides exactly this functionality when combined with PhoneGap. It's even sanctioned by Apple in the latest Developer Agreement. Here are some technical details and then some about Apple's view on it.

I think there is no such solution is available, but you can do it by programmatic way.you can update your cardova app by fetching files from server and updating it.

Check out CodePush from Microsoft. Works with Cordova and React Native.
Appears to be very similar to the "live update" feature from Ionic Cloud.

If you migrate to capacitor, the successor of Cordova there open source solution now.
Capacitor-updater, is the only alternative to ionic AppFlow.
The updater allows you to manage update by yourself, store your zip update where you want and use the download method.
How to start
npm install #capgo/capacitor-updater
npx cap sync
Then in your main JS, this is required to let the updater know the update is valid
import { CapacitorUpdater } from '#capgo/capacitor-updater'
CapacitorUpdater.notifyAppReady()
And lately after checking yourself the current version need update:
const version = await CapacitorUpdater.download({
url: 'https://github.com/Cap-go/demo-app/releases/download/0.0.4/dist.zip',
})
await CapacitorUpdater.set(version); // sets the new version, and reloads the app
After many request of people didn't want to do that themselves, I started Capgo a business to manage all the update process.
All is open source and can be replicate on your own as well.
Doing things for Capacitor is now my main activity, I produce open-source plugin as my main channel of Marketing, I'm solo founder and bootstrapped.
Hope my tool will help you !

how do I open a newly written file from application storage directory in as3 / flex mobile?

Im working on an app (flex 4.12 sdk, using flashbuilder 4.5, creating an app for ios and android, testing on an android htc one primarily)... and am using the camera to capture a file... Im then saving that image to the application storage directory, and I want to open the image in the default web browser or trigger a native dialog (android users) to choose the web browser of their choice... how it opens isnt really important right now -- Im mainly trying to just 'access' it with the device and 'load' it outside my air app...
heres the code I have:
var fs2 : FileStream = new FileStream();
fs2.addEventListener(Event.CLOSE, fileCompleteHandler);
var targetFile : File = File.applicationStorageDirectory.resolvePath("test.jpg");
fs2.openAsync(targetFile, FileMode.WRITE);
fs2.writeBytes(myBMDByteArray,0,myBMDByteArray.length);
fs2.close();
and for the event listener that detects the close of the newly created file:
function fileCompleteHandler(e:Event):void {
trace('File saved.');
trace('exists? ' + targetFile.exists);
trace('the url: ' + targetFile.url);
trace('path: ' + targetFile.nativePath);
navigateToURL(new URLRequest(targetFile.url));
}
I get the following info back from this listener
File saved.
exists? true
the url: app-storage:/test.jpg
path: /data/data/air.com.xxxxx.apptesting.debug/com.xxxxx.apptesting.debug/Local Store/test.jpg
... and problem is that navigateToURL cant access the location where the file is stored (the protocol shows in browser as file:///data/data/air.com/xxx... )
how can I use navigateToURL to get access to this newly created file in the web browser or whatever native application the device associates with the file (its a .JPG file)? I also have had success in adding the newly created image to the camera roll but couldnt figure out how to then open that newly saved image in the native camera roll or whatever app the device chooses or presents to the user for the .jpg format.
I can show the user the image INSIDE my app by referencing the bitmap data fine, I just want to give the user access to the physical file that Im creating on their device.
I even have had success in posting (via urlLoader) the bitmap data as base64 encoding and then creating a file on the server side and loading that url but the encoding and trip to and from the server to give the user the image adds a lot of overhead and it takes a little too long and I'd like to avoid that elongated process.
Thanks for any help anyone can provide - let me know if I need to be more specific in any of this.

Solved the issue... I was able to store / write my file in the documentsDirectory using:
var targetFile : File = File.documentsDirectory.resolvePath('test.jpg');
and then
navigateToURL(new URLRequest(targetFile.url));
And this works fine now. Hopefully it helps someone else! Seems that the storage directory SHOULD work but up until now I've only written to and read files stored there... maybe to open the files one HAS to copy it to a 'safe' location in the filesystem (i.e. sd card?)... will move on to test in ios Now - hope all works well in that OS. Thanks all who chimed in on this.

My first hunch is that you need to specify the proper user-permissions in your application descriptor so you can use the openWith functionality with content from your application.
Remember that you need to specify this for IOS and Android specifically.

On your application.xml you need this permissions set inside android > manifestAdditions > manifest:
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
With this permissions you can save files to applicationStorageDirectory:
const FILE_LOADER:URLLoader = new URLLoader();
FILE_LOADER.addEventListener(Event.COMPLETE, onTempFileComplete);
FILE_LOADER.dataFormat = URLLoaderDataFormat.BINARY;
FILE_LOADER.load(new URLRequest(BASE_URL + filePath));

The applicationStorageDirectory can only be accessed by the application it belongs too when using Android or iOS. navigateToURL() hands over your request to the default browser, which cannot access said directory.
documentsDirectory is a public directory in Android, but not in iOS. So it cannot be used for both platforms. Unfortunately none of the pre-compiled file paths File has point to a public directory in iOS. You can find a table explaining all the pre-compiled paths here