One user reported that my app fails to request directory access when selecting a folder via the ACTION_OPEN_DOCUMENT_TREE intent.
For some reason it does not show my application, instead "Anonymous":
Translated: "Allow Anonymous to access files in Camera. This will let Anonymous access current and future content stored in Camera".
The user has a MIUI 12 with Android 11 on a Mi Note 10 lite.
I have the same just with a Mi Note 10, no issues ofc.
Checked the Android source code:
https://android.googlesource.com/platform/packages/apps/DocumentsUI/+/refs/heads/master/src/com/android/documentsui/picker/ConfirmFragment.java#82
case TYPE_OEPN_TREE:
final Uri treeUri = mTarget.getTreeDocumentUri();
final BaseActivity activity = (BaseActivity) getActivity();
final String target = activity.getCurrentTitle();
final String text = getString(R.string.open_tree_dialog_title,
**getCallingAppName**(getActivity()), target);
message = getString(R.string.open_tree_dialog_message,
**getCallingAppName**(getActivity()), target);
builder.setTitle(text);
builder.setMessage(message);
builder.setPositiveButton(
R.string.allow,
(DialogInterface dialog, int id) -> {
pickResult.increaseActionCount();
mActions.finishPicking(treeUri);
});
break;
#NonNull
public static String getCallingAppName(Activity activity) {
final String anonymous = activity.getString(R.string.anonymous_application);
final String packageName = getCallingPackageName(activity);
if (TextUtils.isEmpty(packageName)) {
return anonymous;
}
final PackageManager pm = activity.getPackageManager();
ApplicationInfo ai;
try {
ai = pm.getApplicationInfo(packageName, 0);
} catch (final PackageManager.NameNotFoundException e) {
return anonymous;
}
CharSequence result = pm.getApplicationLabel(ai);
return TextUtils.isEmpty(result) ? anonymous : result.toString();
}
public static String getCallingPackageName(Activity activity) {
String callingPackage = activity.getCallingPackage();
// System apps can set the calling package name using an extra.
try {
ApplicationInfo info =
activity.getPackageManager().getApplicationInfo(callingPackage, 0);
if (isSystemApp(info) || isUpdatedSystemApp(info)) {
final String extra = activity.getIntent().getStringExtra(
Intent.EXTRA_PACKAGE_NAME);
if (extra != null && !TextUtils.isEmpty(extra)) {
callingPackage = extra;
}
}
} catch (NameNotFoundException e) {
// Couldn't lookup calling package info. This isn't really
// gonna happen, given that we're getting the name of the
// calling package from trusty old Activity.getCallingPackage.
// For that reason, we ignore this exception.
}
return callingPackage;
}
...and it seems that for whatever reason my packagename isn't found. How can can happen?
Asked him to install one of my other apps, and it happens there as well.
Asked him then to install another app from the playstore (FX File Explorer) and there it does not happen.
So it is specific to his device and my app.
So it turned out that this user having that issue turned off the MIUI Optimizations in the developer settings.
Bug report: συσκευη, εκδοση miui, Play store install (alpha 1021). It was impossible to specify a b i o s file or specify a game image directory in when MIUI optimizations are off. Turning them back on fixed the issue and directories are scanned normally. Also on the popup to allow folder access the app displays as "Anonymous" instead of AetherSX2 on my system. Some developer was talking about having the same issue here.
please help me I am trying to get text from stack of notifications. I am getting following error.
java.lang.NoSuchFieldException: No field mActions in class
Landroid/app/Notification$BuilderRemoteViews; (declaration of
'android.app.Notification$BuilderRemoteViews' appears in
/system/framework/framework.jar)
I am using NotificationListenerService and
private List<String> getMessages(Notification notification) {
RemoteViews views = notification.bigContentView;
if (views == null) views = notification.contentView;
if (views == null) return null;
List<String> text = new ArrayList<String>();
try {
Field field = views.getClass().getDeclaredField(Constants.ACTIONS);
field.setAccessible(true);
#SuppressWarnings("unchecked")
ArrayList<Parcelable> actions = (ArrayList<Parcelable>) field.get(views);
for (Parcelable p : actions) {
Parcel parcel = Parcel.obtain();
p.writeToParcel(parcel, 0);
parcel.setDataPosition(0);
int tag = parcel.readInt();
if (tag != 2) continue;
parcel.readInt();
String methodName = parcel.readString();
if (methodName == null) {
continue;
} else if (methodName.equals(Constants.SET_TEXT)) {
parcel.readInt();
methodName.getBytes();
String gettingText = TextUtils.CHAR_SEQUENCE_CREATOR.createFromParcel(parcel).toString().trim();
text.add(gettingText);
} else if (methodName.equals(Constants.SET_TIME)) {
parcel.readInt();
String gettingText = new SimpleDateFormat("h:mm a").format(new Date(parcel.readLong()));
text.add(gettingText);
}
parcel.recycle();
}
} catch (Exception e) {
Log.e("NotificationClassifier", e.toString());
}
return text;
}
This is working fine in android 4,5 but's its getting crash on Android 7, Getting error like mAction field not available.
Please any one help me to solve this, I am stuck from two days.
Thank you
You are using reflection to access method names and you are not switching the code for multiple platforms. The fields/methods that you are trying to access, change over time on multiple versions of the OS, so if you really want to have the reflection, you have to study what changes they were.
Generally, reflection should really be last resort, since on Android, the base code varies from version to version, and even from manufacturer to manufacturer.
Created an app that used the device's uniqueID which is fetched by the following code snippet
String deviceId = Settings.Secure.getString(getContentResolver(),
Settings.Secure.ANDROID_ID);
When the user tries to clone the app by app cloner, then it creates a different deviceID and the app is not allowed to work
Is there any way to make our app non clonable
or
Any possible way to have the same deviceId even if the app instance is cloned?
Is there any way to find out whether the app is running in a cloned instance?
Applications like Cloner usually change your application's package name so you can retrieve package name and check if it is changed or not.
if (!context.getPackageName().equals("your.package.name")){
// close the app or do whatever
}
Also they usually sign cloned apk so the signature might be different from yours, you can check if signature is changed or not. I usually use this function:
#SuppressLint("PackageManagerGetSignatures")
public static int getCertificateValue(Context ctx){
try {
Signature[] signatures = null;
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
try {
signatures = ctx.getPackageManager().getPackageInfo(ctx.getPackageName(), PackageManager.GET_SIGNING_CERTIFICATES).signingInfo.getApkContentsSigners();
}catch (Throwable ignored){}
}
if (signatures == null){
signatures = ctx.getPackageManager().getPackageInfo(ctx.getPackageName(), PackageManager.GET_SIGNATURES).signatures;
}
int value = 1;
for (Signature signature : signatures) {
value *= signature.hashCode();
}
return value;
} catch (Exception e) {
e.printStackTrace();
}
return 0;
}
public static boolean checkCertificate(Context ctx, int trustedValue){
return getCertificateValue(ctx) == trustedValue;
}
Before releasing your app call getCertificateValue(context) and write down the value and alongside with package name, check if that value matches the value that you get in runtime.
PS: as #vladyslav-matviienko said hackers will always find a way so try to make cloning harder by running some obfuscations on hardcoded package name and that value. Also try to tangle and spread these kind of logics all around the source code.
I found a story in proandroiddev by Siddhant Panhalkar and with some minor changes it's work perfectly in Mi device I did checked in Mi phones default Dual apps and some third party apps from playstore and it prevents from cloning (means not working properly after clone).
private const val APP_PACKAGE_DOT_COUNT = 3 // number of dots present in package name
private const val DUAL_APP_ID_999 = "999"
private const val DOT = '.'
fun CheckAppCloning(activity: Activity) {
val path: String = activity.filesDir.getPath()
if (path.contains(DUAL_APP_ID_999)) {
killProcess(activity)
} else {
val count: Int = getDotCount(path)
if (count > APP_PACKAGE_DOT_COUNT) {
killProcess(activity)
}
}
}
private fun getDotCount(path: String): Int {
var count = 0
for (element in path) {
if (count > APP_PACKAGE_DOT_COUNT) {
break
}
if (element == DOT) {
count++
}
}
return count
}
private fun killProcess(context: Activity) {
context.finish()
android.os.Process.killProcess( android.os.Process.myPid())
}
I programmed an app that can send a message to twitter with an image attached. It works! I tested it on several devices and asked other people to do the same. It even works for a Direct Message when a twitter friend is selected. However, it does not work when "Direct Message" is selected. This forces the user to select a friend directly instead of selecting him via "Direct Message" (which is really strange) otherwise the picture is not attached. Just have a look at the screenshot:
Here is my Xamarin Android programming code. Let me know how to fix it. Currently, all options work, even selecting my friend but not "Direct Message". I also need to tell that I do not have any issue with the twitter text I expect to see in the tweet.
public bool TweetImage(Bitmap imageToTweet)
{
var messageIntent = context.FindMessageIntent(this.twitterConstants.PackageName);
if (messageIntent == null)
{
return false;
}
string outputFileBMP = SaveBitmap(imageToTweet);
context.Tweet(messageIntent, outputFileBMP, this.twitterConstants.DefaultTwitterText, this.twitterConstants.ChooserMessage);
return true;
}
and
public static Intent FindMessageIntent(this ContextWrapper contextWrapper, params string[] packageNames)
{
Intent wantedIntent = new Intent();
wantedIntent.SetType("text/plain");
var resolveInfos = contextWrapper.PackageManager.QueryIntentActivities(wantedIntent, PackageInfoFlags.MatchDefaultOnly);
var result = (from r in resolveInfos
from p in packageNames
where p == r.ActivityInfo.PackageName
select p).FirstOrDefault();
if (result != null)
{
wantedIntent.SetPackage(result);
return wantedIntent;
}
return null;
}
and
public static void Tweet(this ContextWrapper contextWrapper, Intent messageIntent, string filePath = null, string message = null, string chooserMessage = null)
{
if (filePath != null)
{
using (var file = new Java.IO.File(filePath))
{
messageIntent.PutExtra(Intent.ExtraStream, Android.Net.Uri.FromFile(file));
}
}
if (message != null)
{
messageIntent.PutExtra(Intent.ExtraText, message);
}
if (chooserMessage != null)
{
using (var chooser = Intent.CreateChooser(messageIntent, chooserMessage))
{
contextWrapper.StartActivity(chooser);
}
return;
}
contextWrapper.StartActivity(messageIntent);
}
Please note that I am using Android and need a solution based on Android (intent based).
Sadly, Twitter don't provide API access for uploading images via DM.
If you are able to use Twitter's private API, you should be able to attach a media_id to your DM. But other than that, you're out of luck.
Sorry.
I've got an Android app which scans for all Apps installed on the device and then reports this to a server (it's an MDM agent). Any suggestions on how to get the Category of the App? Everyone has a different list of Categories, but basically something like Game, Entertainment, Tools/Utilities, etc.
From what I can tell there is nothing related to Category stored on the device itself. I was thinking of using the android market API to search for the application in the market and use the Category value returned by the search. Not sure how successful this will be finding a match. Any suggestions on how best to do this?
Any suggestions on a different approach?
Thanks in advance.
mike
I know that this is an old post, but for anyone still looking for this, API level 26 (O) has added categories to android.content.pm.ApplicationInfo.
From the docs https://developer.android.com/reference/android/content/pm/ApplicationInfo#category:
public int category
The category of this app. Categories are used to cluster multiple apps together into meaningful groups, such as when summarizing battery, network, or disk usage. Apps should only define this value when they fit well into one of the specific categories.
Set from the R.attr.appCategory attribute in the manifest. If the manifest doesn't define a category, this value may have been provided by the installer via PackageManager#setApplicationCategoryHint(String, int).
Value is CATEGORY_UNDEFINED, CATEGORY_GAME, CATEGORY_AUDIO, CATEGORY_VIDEO, CATEGORY_IMAGE, CATEGORY_SOCIAL, CATEGORY_NEWS, CATEGORY_MAPS, or CATEGORY_PRODUCTIVITY
One can now do something like:
PackageManager pm = context.getPackageManager();
ApplicationInfo applicationInfo = pm.getApplicationInfo(packageName, 0);
if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O) {
int appCategory = applicationInfo.category;
String categoryTitle = (String) ApplicationInfo.getCategoryTitle(context, appCategory)
// ...
}
if you get for each application its package name, you could ask directly to play store which category an app belongs, parsing html response page with this library:
org.jsoup.jsoup1.8.3
Here's a snippet to solve your problem:
public class MainActivity extends AppCompatActivity {
public final static String GOOGLE_URL = "https://play.google.com/store/apps/details?id=";
public static final String ERROR = "error";
...
private class FetchCategoryTask extends AsyncTask<Void, Void, Void> {
private final String TAG = FetchCategoryTask.class.getSimpleName();
private PackageManager pm;
private ActivityUtil mActivityUtil;
#Override
protected Void doInBackground(Void... errors) {
String category;
pm = getPackageManager();
List<ApplicationInfo> packages = pm.getInstalledApplications(PackageManager.GET_META_DATA);
Iterator<ApplicationInfo> iterator = packages.iterator();
while (iterator.hasNext()) {
ApplicationInfo packageInfo = iterator.next();
String query_url = GOOGLE_URL + packageInfo.packageName;
Log.i(TAG, query_url);
category = getCategory(query_url);
// store category or do something else
}
return null;
}
private String getCategory(String query_url) {
boolean network = mActivityUtil.isNetworkAvailable();
if (!network) {
//manage connectivity lost
return ERROR;
} else {
try {
Document doc = Jsoup.connect(query_url).get();
Element link = doc.select("span[itemprop=genre]").first();
return link.text();
} catch (Exception e) {
return ERROR;
}
}
}
}
}
You could make these queries in an AsyncTask, or in a service. Hope that you find it helpful.
I also faced the same issue. The solution for the above query is stated below.
Firstly, download the Jsoup library or download the jar file.
or
Add this to your build.gradle(Module: app) implementation 'org.jsoup:jsoup:1.11.3'
private class FetchCategoryTask extends AsyncTask<Void, Void, Void> {
private final String TAG = FetchCategoryTask.class.getSimpleName();
private PackageManager pm;
//private ActivityUtil mActivityUtil;
#Override
protected Void doInBackground(Void... errors) {
String category;
pm = getPackageManager();
List<ApplicationInfo> packages = pm.getInstalledApplications(PackageManager.GET_META_DATA);
Iterator<ApplicationInfo> iterator = packages.iterator();
// while (iterator.hasNext()) {
// ApplicationInfo packageInfo = iterator.next();
String query_url = "https://play.google.com/store/apps/details?id=com.imo.android.imoim"; //GOOGLE_URL + packageInfo.packageName;
Log.i(TAG, query_url);
category = getCategory(query_url);
Log.e("CATEGORY", category);
// store category or do something else
//}
return null;
}
private String getCategory(String query_url) {
try {
Document doc = Jsoup.connect(query_url).get();
Elements link = doc.select("a[class=\"hrTbp R8zArc\"]");
return link.text();
} catch (Exception e) {
Log.e("DOc", e.toString());
}
}
}
In return, you will get Application Company Name and category of the application
I made a Kotlin solution based on the answer from #Ankit Kumar Singh.
This solution maps the category to an enum, in case you want to do other things than just show it.
import kotlinx.coroutines.*
import org.jsoup.Jsoup
import javax.inject.Inject
import javax.inject.Singleton
class AppCategoryService {
companion object {
private const val APP_URL = "https://play.google.com/store/apps/details?id="
private const val CAT_SIZE = 9
private const val CATEGORY_STRING = "category/"
}
suspend fun fetchCategory(packageName: String): AppCategory {
val url = "$APP_URL$packageName&hl=en" //https://play.google.com/store/apps/details?id=com.example.app&hl=en
val categoryRaw = parseAndExtractCategory(url) ?: return AppCategory.OTHER
return AppCategory.fromCategoryName(categoryRaw)
}
#Suppress("BlockingMethodInNonBlockingContext")
private suspend fun parseAndExtractCategory(url: String): String? = withContext(Dispatchers.IO) {
return#withContext try {
val text = Jsoup.connect(url).get()?.select("a[itemprop=genre]") ?: return#withContext null
val href = text.attr("abs:href")
if (href != null && href.length > 4 && href.contains(CATEGORY_STRING)) {
getCategoryTypeByHref(href)
} else {
null
}
} catch (e: Throwable) {
null
}
}
private fun getCategoryTypeByHref(href: String) = href.substring(href.indexOf(CATEGORY_STRING) + CAT_SIZE, href.length)
}
And here is the enum with all the possible values at of this moment in time:
// Note: Enum name matches API value and should not be changed
enum class AppCategory {
OTHER,
ART_AND_DESIGN,
AUTO_AND_VEHICLES,
BEAUTY,
BOOKS_AND_REFERENCE,
BUSINESS,
COMICS,
COMMUNICATION,
DATING,
EDUCATION,
ENTERTAINMENT,
EVENTS,
FINANCE,
FOOD_AND_DRINK,
HEALTH_AND_FITNESS,
HOUSE_AND_HOME,
LIBRARIES_AND_DEMO,
LIFESTYLE,
MAPS_AND_NAVIGATION,
MEDICAL,
MUSIC_AND_AUDIO,
NEWS_AND_MAGAZINES,
PARENTING,
PERSONALIZATION,
PHOTOGRAPHY,
PRODUCTIVITY,
SHOPPING,
SOCIAL,
SPORTS,
TOOLS,
TRAVEL_AND_LOCAL,
VIDEO_PLAYERS,
WEATHER,
GAMES;
companion object {
private val map = values().associateBy(AppCategory::name)
private const val CATEGORY_GAME_STRING = "GAME_" // All games start with this prefix
fun fromCategoryName(name: String): AppCategory {
if (name.contains(CATEGORY_GAME_STRING)) return GAMES
return map[name.toUpperCase(Locale.ROOT)] ?: OTHER
}
}
}
private fun getCategory(){
val GOOGLE_URL = "https://play.google.com/store/apps/details?id=com.google.android.deskclock"
lifecycleScope.launch(Dispatchers.IO) {
val doc: Document = Jsoup.connect(GOOGLE_URL).get()
val index = doc.body().data().indexOf("applicationCategory")
val simpleString = doc.body().data().subSequence(index,index+100)
val data = simpleString.split(":")[1].split(",")[0]
Log.e("DATA-->",data.toString())
}
}
You can use below AsyncTask for extract Android app category from playStore by using app package id.
import android.content.Context;
import android.content.pm.PackageManager;
import android.os.AsyncTask;
import android.util.Log;
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import org.jsoup.select.Elements;
import java.io.IOException;
public class GetAppCategory extends AsyncTask<String, Void, String> {
//Main URL for each app on Play Store
public static final String APP_URL = "https://play.google.com/store/apps/details?id=";
//Use below String if extracting 'CATEGORY' from href tag.
private final String CATEGORY_STRING = "category/";
private final int cat_size = 9;
/*Use below String for identified 'GAME' apps, which must start with this prefix.
Here I only display 'Games' as category for all Games app instead of showing their subCategory also*/
private final String CATEGORY_GAME_STRING = "GAME_";
//Name of the app package for which you want to get category.
private String packageName = null;
private PackageManager pm = null;
//Activity or Application context as per requirement.
private Context appContext;
/* You can add default system app OR non play store app package name here as comma seprated for ignore them
and set their category directly 'Others' OR anythings you wish. */
private final String extractionApps = "com.android.providers.downloads.ui, com.android.contacts," +
" com.android.gallery3d, com.android.vending, com.android.calculator2, com.android.calculator," +
" com.android.deskclock, com.android.messaging, com.android.settings, com.android.stk";
//Class level TAG, use for Logging.
private final String TAG = "GetAppCategory";
/**
* #param packageName: package name of the app, you want to extract category.
* #param appContext: Activity/Application level Context ap per requirement.
*/
public GetAppCategory(String packageName, Context appContext) {
this.packageName = packageName;
this.appContext = appContext;
}
#Override
protected String doInBackground(String... params) {
try {
pm = appContext.getPackageManager();
if (packageName != null && packageName.length() > 1) {
if (packageName.contains("package:")) {
packageName = packageName.replace("package:", "");
}
/**
* Mathod used for parse play store html page and extract category from their.
*/
String appCategoryType = parseAndExtractCategory(packageName);
Log.i(TAG, "package :" + packageName);
Log.i(TAG, "APP_CATEGORY: " + appCategoryType);
}
} catch (Exception e) {
//TODO:: Handle Exception
e.printStackTrace();
} finally {
//TODO::
}
return null;
}
#Override
protected void onPostExecute(String result) {
}
/**
* #param packageName
* #return
*/
private String parseAndExtractCategory(String packageName) {
//You can pass hl={language_code} for get category in some other langauage also other than English.
//String url = APP_URL + packageName + "&hl=" + appContext.getString(R.string.app_lang);
String url = APP_URL + packageName + "&hl=en"; //{https://play.google.com/store/apps/details?id=com.example.app&hl=en}
String appCategoryType = null;
String appName = null;
try {
if (!extractionApps.contains(packageName)) {
Document doc = null;
try {
doc = Jsoup.connect(url).get();
if (doc != null) {
//TODO: START_METHOD_1
//Extract category String from a <anchor> tag value directly.
//NOTE: its return sub category text, for apps with multiple sub category.
//Comment this method {METHOD_1}, if you wish to extract category by href value.
Element CATEGORY_SUB_CATEGORY = doc.select("a[itemprop=genre]").first();
if (CATEGORY_SUB_CATEGORY != null) {
appCategoryType = CATEGORY_SUB_CATEGORY.text();
}
//TODO: END_METHOD_1
//TODO: START_METHOD_2
// Use below code only if you wist to extract category by href value.
//Its return parent or Main Category Text for all app.
//Comment this method {METHOD_2}, If you wihs to extract category from a<anchor> value.
if (appCategoryType == null || appCategoryType.length() < 1) {
Elements text = doc.select("a[itemprop=genre]");
if (text != null) {
if (appCategoryType == null || appCategoryType.length() < 2) {
String href = text.attr("abs:href");
if (href != null && href.length() > 4 && href.contains(CATEGORY_STRING)) {
appCategoryType = getCategoryTypeByHref(href);
}
}
}
}
//TODO: END_METHOD_2
if (appCategoryType != null && appCategoryType.length() > 1) {
/**
* Ger formatted category String by removing special character.
*/
appCategoryType = replaceSpecialCharacter(appCategoryType);
}
}
} catch (IOException e) {
//appCategoryType = appContext.getString(R.string.category_others);
appCategoryType = "OTHERS";
//TODO:: Handle Exception
e.printStackTrace();
}
} else {
//appCategoryType = appContext.getString(R.string.category_others);
appCategoryType = "OTHERS";
}
} catch (Exception e) {
//TODO:: Handle Exception
e.printStackTrace();
}
return appCategoryType;
}
/**
* #param href
* #return
*/
private String getCategoryTypeByHref(String href) {
String appCategoryType = null;
try {
appCategoryType = href.substring((href.indexOf(CATEGORY_STRING) + cat_size), href.length());
if (appCategoryType != null && appCategoryType.length() > 1) {
if (appCategoryType.contains(CATEGORY_GAME_STRING)) {
//appCategoryType = appContext.getString(R.string.games);
appCategoryType = "GAMES";
}
}
} catch (Exception e) {
//TODO:: Handle Exception
e.printStackTrace();
}
return appCategoryType;
}
/**
* #param appCategoryType
* #return: formatted String
*/
private String replaceSpecialCharacter(String appCategoryType) {
try {
//Find and Replace '&' with '&' in category Text
if (appCategoryType.contains("&")) {
appCategoryType = appCategoryType.replace("&", " & ");
}
//Find and Replace '_AND_' with ' & ' in category Text
if (appCategoryType.contains("_AND_")) {
appCategoryType = appCategoryType.replace("_AND_", " & ");
}
//Find and Replace '_' with ' ' <space> in category Text
if (appCategoryType.contains("_")) {
appCategoryType = appCategoryType.replace("_", " ");
}
} catch (Exception e) {
//TODO:: Handle Exception
e.printStackTrace();
}
return appCategoryType;
}
}
It's requires jsoup library for parsing the html page. you can find it here org.jsoup.jsoup1.11.1
Probably a bit late, but the problem is still here.
The OP has the advantage because of sending those results to the API (here I assume that the API is managed by the OP or his API colleagues at least).
So, for anyone with the similar problem I'd suggest following:
Collect all the package names you're interested in from device.
Send that data to the your API
API should extract package names and try to read results from its cache / db...
For those packages that do not exist in cache / db make "market API" call and extract category - save it to the db / cache for reuse in this iteration.
When all requests (to cache / db and market API) are completed do whatever you like with the results.
Things to consider:
When multiple users try to query your API for a same package name and you don't have a category for that package in your cache / db...
Do 1 request to "market API" for packagex and update packagex in your cache / db to "waiting for results" state - next request should either get a "waiting for results" or a result that "market API" returned.
One should also consider a fallback for possible "market API" fails (market API not working, not a google play app, or something similar). This decision is basically tied to your domain and the business trend that you're trying to catch will force a decision about this for you. If you're really into getting this category stuff sorted out you could pipeline this fallback to human decision and update your API db / cache for packagex accordingly.
put up a nice API that would handle these and similar scenarios gracefully then one could probably even commercialize it up to a certain extent and "market API endpoint" - AKA play store package details page. That page would lose a big part of it's fake users :)