How to clear the cache of another application?-CodePudding

I'm trying to delete the cache, not my application, but when I look in the settings, everything remains the same. As far as I understand, you need to find the /cache folder in the application package and delete it, are there any other ways? Now I get a list of applications installed on the phone:

   private fun getListOfAppsInfo(activity: Activity, isAll: Int): MutableList<ApplicationInfo> {
        val appForReturnedList = mutableListOf<ApplicationInfo>()
        val appsInfoList: MutableList<ApplicationInfo> = if (Build.VERSION.SDK_INT < Build.VERSION_CODES.R) {
            activity.packageManager.getInstalledApplications(PackageManager.GET_META_DATA)
        } else {
            val intent = Intent(Intent.ACTION_MAIN, null)
            intent.addCategory(Intent.CATEGORY_LAUNCHER)
            val arrayAppsNew = mutableListOf<ApplicationInfo>()
            val listAppsReturned = activity.packageManager.queryIntentActivities(intent, 0)
            listAppsReturned.forEach {
                arrayAppsNew.add(it.activityInfo.applicationInfo)
            }
            arrayAppsNew
        }
        val appsInstalled: MutableList<ApplicationInfo> = mutableListOf()
        val appsSystem: MutableList<ApplicationInfo> = mutableListOf()
        (appsInfoList.indices).forEach { i ->
//            if (appsInfoList[i].packageName != activity.packageName) {
                if (appsInfoList[i].flags and ApplicationInfo.FLAG_SYSTEM == 1) {
                    appsSystem.add(appsInfoList[i])
                } else {
                    appsInstalled.add(appsInfoList[i])
                    getPackagePathByPackageName(this, appsInfoList[i].packageName)
                }
//            }
        }

        when (isAll) {
            ALL_APPS -> {
                appForReturnedList.addAll(appsInstalled)
                appForReturnedList.addAll(appsSystem)
            }
            USER_APPS -> appForReturnedList.addAll(appsInstalled)
            SYSTEM_APPS -> appForReturnedList.addAll(appsSystem)
            else -> appForReturnedList.addAll(appsInstalled)
        }

        return appForReturnedList
    }

 private fun getAppsListInfo(activity: Activity, isAll: Int): ArrayList<String> {
        val appsArrayList: ArrayList<String> = ArrayList()

        for (app in getListOfAppsInfo(activity, isAll)) {
            appsArrayList.add(app.packageName)
        }

        return appsArrayList
    }

Then, by the package name, I find the path to the desired folder, if there is one:

private fun getPackagePathByPackageName(activity: Activity, packageName: String): String {
        val packageManager = activity.packageManager
        var packagePath = packageName
        val packageInfo = packageManager.getPackageInfo(packagePath, 0)
        var appCacheDir = ""
        packagePath = packageInfo.applicationInfo.dataDir
        val dir = File("$packagePath/cache")
        if (dir.exists()) {
            appCacheDir = dir.absolutePath
        }
        return appCacheDir
    }

And delete it:

  private fun deleteCache(context: Context, packagePathByPackageName: String) {
        try {
//            val dir: File = context.cacheDir
            val dir = File(packagePathByPackageName)
            deleteDir(dir)
        } catch (e: Exception) {
        }
    }

    private fun deleteDir(dir: File?): Boolean {
        return if (dir != null && dir.isDirectory) {
            dir.deleteRecursively()
            val children: Array<String> = dir.list()
            for (i in children.indices) {
                val success = deleteDir(File(dir, children[i]))
                if (!success) {
                    return false
                }
            }
            dir.deleteRecursively()
        } else if (dir != null && dir.isFile) {
            dir.deleteRecursively()
        } else {
            false
        }
    }

But nothing happens, even if I substitute the path to my application. Here is the list of permissions:

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_INTERNAL_STORAGE" />
<uses-permission android:name="android.permission.ACTION_MANAGE_WRITE_SETTINGS " />
<uses-permission
        android:name="android.permission.CLEAR_APP_CACHE"
        tools:ignore="ProtectedPermissions" />
<uses-permission
        android:name="android.permission.MANAGE_EXTERNAL_STORAGE"
        tools:ignore="ScopedStorage" />
<uses-permission android:name="android.permission.REQUEST_DELETE_PACKAGES" />
<uses-permission
        android:name="android.permission.PACKAGE_USAGE_STATS"
        tools:ignore="ProtectedPermissions" />
<uses-permission
        android:name="android.permission.GET_PACKAGE_SIZE"
        tools:ignore="ProtectedPermissions" />

<queries>
        <package android:name="QUERY_ALL_PACKAGES" />
        <package android:name="com.android.settings" />

        <intent>
            <action android:name="android.intent.action.MAIN" />
        </intent>
        <intent>
            <action android:name="android.intent.action.VIEW" />
        </intent>
        <intent>
            <action android:name="android.intent.action.POWER_USAGE_SUMMARY" />
        </intent>
        <intent>
            <action android:name="android.intent.action.SEND" />
        </intent>
</queries>

And I request the permissions READ_EXTERNAL_STORAGE, WRITE_EXTERNAL_STORAGE, ACTION_MANAGE_APP_ALL_FILES_ACCESS_PERMISSION, maybe some are missing? Or this cannot be done at all, it seems like based on this https://developer.android.com/training/data-storage/app-specific after api 29 you cannot get such access. I tested it on a 30 phone and the folders with the cache are really not visible, on 21 they are visible but do not delete anything, it's the same on emulators. Can you please tell me if this can be done at all, if so, what am I doing wrong?

CodePudding user response：

        packagePath = packageInfo.applicationInfo.dataDir
        val dir = File("$packagePath/cache")

You have neither read nor write access to this location for other apps. That has been true since Android 1.0, released nearly 14 years ago at this point.