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Android 9 Behavioral Changes

In this document, we will explain the various Android 9 (version Pie and API Level 28) behavioral changes that are observed when apps use Android targetSDK version 28 and run on Android 9.0 devices.

Network Security

Android Pie recommends using secure https connections henceforth. Network connections with scheme as http do not work on apps targeting Android Pie.

HTTP connections will fail with the following exception message: Cleartext HTTP traffic to * not permitted

Consequently, you must migrate all http URLs to https URLs used in Volt MX Iris Android application.

If your app needs to enable cleartext for specific domains, you must explicitly set cleartextTrafficPermitted to true for those domains in your app's Network Security Configuration.

For example, if you want to permit clear text traffic to and its sub-domains, use the following network_security_config.xml.

<?xml version = "1.0" encoding = "utf-8"?>  
 <domain-config cleartextTrafficPermitted = "true">   
 <domain includeSubdomains = "true"> </domain>
</domain-config> </network-security-config>                     

For more information, click here.

Restrictions on the Use of non-SDK Interfaces

For apps running on Android 9 (API level 28), Android introduces new restrictions on the use of non-SDK interfaces, whether directly, via reflection, or via JNI. For more information on these restrictions, click here.

For more information on the types of SDK interfaces and their descriptions, click here.

  • whitelist: The SDK provided methods that can be used in the application.

  • light-greylist: When the application uses non-SDK methods or fields that are still accessible, this log is printed in Debug mode: Accessing hidden ‚Ķ(light grey list).
    No log is printed in Release mode.

  • blacklist: The usage of these APIs or fields are restricted regardless of the target SDK. The platform will behave as if the interface is absent.

    • Android Framework will throw NoSuchMethodError or NoSuchFieldException whenever the app tries to use blacklisted methods.
      When the app tries to list or enumerate blacklisted fields or methods of a particular class, they will not be listed.
  • dark-greylist: For apps whose target SDK is earlier than API level 28, the use of a dark greylist interface is permitted.
    For apps whose target SDK is API level 28 or later, the same behavior is observed as in the case of blacklist.

    Note: You must build a app that can be debugged, and then run your tests for the app. A logcat warning is printed of the form Accessing hidden field|method... for every use of non-SDK interfaces, including that are denied.

    Important: You must not use the hidden interfaces that are listed in darklist and blacklist via NFI or FFI. If any of these interfaces are used, the application may crash.