Session demo crashes in Android 6

[nift4]

Version

Media3 main branch

More version details

0b20baa

Devices that reproduce the issue

API 23 emulator

Devices that do not reproduce the issue

N/A

Reproducible in the demo app?

Yes

Reproduction steps

1. Open the session-demo app

Expected result

It works

Actual result

2025-12-27 13:25:01.830  4306-4306  AndroidRuntime          androidx.media3.demo.session    E  FATAL EXCEPTION: main
                                                                                               Process: androidx.media3.demo.session, PID: 4306
                                                                                               java.lang.NoClassDefFoundError: androidx.media3.cast.MediaRouteButtonFactory$$ExternalSyntheticLambda0
                                                                                               	at androidx.media3.cast.MediaRouteButtonFactory.setUpMediaRouteButton(MediaRouteButtonFactory.java:174)
                                                                                               	at androidx.media3.cast.MediaRouteButtonFactory.setUpMediaRouteButton(MediaRouteButtonFactory.java:147)
                                                                                               	at androidx.media3.demo.session.MainActivity.onCreateOptionsMenu(MainActivity.kt:106)
                                                                                               	at android.app.Activity.onCreatePanelMenu(Activity.java:2846)
                                                                                               	at androidx.activity.ComponentActivity.onCreatePanelMenu(ComponentActivity.java:520)
                                                                                               	at androidx.fragment.app.FragmentActivity.onCreatePanelMenu(FragmentActivity.java:287)
                                                                                               	at androidx.appcompat.view.WindowCallbackWrapper.onCreatePanelMenu(WindowCallbackWrapper.java:95)
                                                                                               	at androidx.appcompat.app.AppCompatDelegateImpl$AppCompatWindowCallback.onCreatePanelMenu(AppCompatDelegateImpl.java:3429)
                                                                                               	at leakcanary.FixedWindowCallback.onCreatePanelMenu(FixedWindowCallback.java:63)
                                                                                               	at androidx.appcompat.app.AppCompatDelegateImpl.preparePanel(AppCompatDelegateImpl.java:2027)
                                                                                               	at androidx.appcompat.app.AppCompatDelegateImpl.doInvalidatePanelMenu(AppCompatDelegateImpl.java:2313)
                                                                                               	at androidx.appcompat.app.AppCompatDelegateImpl$2.run(AppCompatDelegateImpl.java:281)
                                                                                               	at android.os.Handler.handleCallback(Handler.java:739)
                                                                                               	at android.os.Handler.dispatchMessage(Handler.java:95)
                                                                                               	at android.os.Looper.loop(Looper.java:148)
                                                                                               	at android.app.ActivityThread.main(ActivityThread.java:5417)
                                                                                               	at java.lang.reflect.Method.invoke(Native Method)
                                                                                               	at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
                                                                                               	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)

Media

can't even get to the selection screen :)

Bug Report

• You will email the zip file produced by adb bugreport to android-media-github@google.com after filing this issue.

[oceanjules]

Hi Nick,

Thanks for the report! You are absolutely right, just reproduced myself and indeed only on API 23.

Looks like after adding lib-cast to session-demo we contaminated the demo with some java8+ features.

Immediate fix in demos/session/build.gradle: hacky, but fast (similar to 33b4148 and 653538e)

• compileOptions.coreLibraryDesugaringEnabled true and
• coreLibraryDesugaring "com.android.tools:desugar_jdk_libs:" + desugarJdkLibsVersion

Cleaner fix Remove the unnecessary dependency on Consumer and -> lambdas and method references from:

https://github.com/androidx/media/blob/main/libraries/cast/src/main/java/androidx/media3/cast/MediaRouteButtonFactory.java#L262-L263

  private static ListenableFuture<Void> setUpMediaRouteButton(
      Context context, Consumer<MediaRouteSelector> onCompletion) {

and https://github.com/androidx/media/blob/main/libraries/cast/src/main/java/androidx/media3/cast/MediaRouteButtonFactory.java#L171-L179

setUpMediaRouteButton(
            context, selector -> mediaRouteActionProvider.setRouteSelector(selector));

In fact, further down there is a call to accept which the linter helpfully highlights as problematic Call requires API level 24 (current min is 23): java.util.function.Consumer#accept

void onMediaRouteSelectorChanged(MediaRouteSelector selector) {
  if (!selector.isEmpty()) {
    onCompletion.accept(selector);
    completer.set(null);
  }

I will work on the latter, seems simple since it's not touching any public APIs.

[oceanjules]

A simpler fix than expected! Closing the issue now and thanks again for the heads up about older APIs.

[nift4]

Thanks for the quick fix!