Flutter应用使用telephony包接收短信时Release版本崩溃求助

我开发了一款可自动扫描接收短信的Flutter应用，Debug版本运行一切正常，但Release版本在收到新短信时会崩溃。已按照telephony包文档配置所有权限，且在调用后台函数前添加了@pragma('vm:entry-point')注解。

崩溃堆栈信息 #

E/AndroidRuntime(22045): FATAL EXCEPTION: main
E/AndroidRuntime(22045): Process: com.example.expense, PID: 22045
E/AndroidRuntime(22045): java.lang.RuntimeException: Unable to start receiver com.shounakmulay.telephony.sms.IncomingSmsReceiver: java.lang.NullPointerException: Attempt to read from field 'java.lang.String io.flutter.view.FlutterCallbackInformation.callbackLibraryPath' on a null object reference in method 'java.lang.String a1.a$b.toString()'
E/AndroidRuntime(22045):        at android.app.ActivityThread.handleReceiver(ActivityThread.java:4561)
E/AndroidRuntime(22045):        at android.app.ActivityThread.-$$Nest$mhandleReceiver(Unknown Source:0)
E/AndroidRuntime(22045):        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2308)
E/AndroidRuntime(22045):        at android.os.Handler.dispatchMessage(Handler.java:106)
E/AndroidRuntime(22045):        at android.os.Looper.loopOnce(Looper.java:240)
E/AndroidRuntime(22045):        at android.os.Looper.loop(Looper.java:351)
E/AndroidRuntime(22045):        at android.app.ActivityThread.main(ActivityThread.java:8364)
E/AndroidRuntime(22045):        at java.lang.reflect.Method.invoke(Native Method)
E/AndroidRuntime(22045):        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:584)
E/AndroidRuntime(22045):        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1013)
E/AndroidRuntime(22045): Caused by: java.lang.NullPointerException: Attempt to read from field 'java.lang.String io.flutter.view.FlutterCallbackInformation.callbackLibraryPath' on a null object reference in method 'java.lang.String a1.a$b.toString()'
E/AndroidRuntime(22045):        at a1.a$b.toString(Unknown Source:22)
E/AndroidRuntime(22045):        at java.lang.String.valueOf(String.java:3657)
E/AndroidRuntime(22045):        at java.lang.StringBuilder.append(StringBuilder.java:132)
E/AndroidRuntime(22045):        at a1.a.i(Unknown Source:27)
E/AndroidRuntime(22045):        at s0.b.k(Unknown Source:62)
E/AndroidRuntime(22045):        at com.shounakmulay.telephony.sms.IncomingSmsReceiver.b(Unknown Source:30)
E/AndroidRuntime(22045):        at com.shounakmulay.telephony.sms.IncomingSmsReceiver.c(Unknown Source:129)
E/AndroidRuntime(22045):        at com.shounakmulay.telephony.sms.IncomingSmsReceiver.onReceive(Unknown Source:86)
E/AndroidRuntime(22045):        at android.app.ActivityThread.handleReceiver(ActivityThread.java:4545)
E/AndroidRuntime(22045):        ... 9 more

排查与解决方案 #

从堆栈信息看，崩溃根源是FlutterCallbackInformation.callbackLibraryPath空指针，这通常和Release模式下代码混淆、后台入口未被正确保留有关，可按以下步骤排查：

• 确认@pragma('vm:entry-point')注解位置：必须直接放在顶级后台回调函数上方，不能嵌套在类或其他函数内部，示例：

  @pragma('vm:entry-point')
  void backgroundMessageHandler(SmsMessage message) {
    // 后台短信处理逻辑
  }
  

  若回调是类的静态方法，注解也需直接加在静态方法上。

• 添加ProGuard/R8混淆规则：Release模式下的代码混淆可能删除了Flutter回调相关类，在android/app/proguard-rules.pro中添加以下规则：

  # 保留telephony包所有类
  -keep class com.shounakmulay.telephony.** { *; }
  # 保留Flutter回调信息类
  -keep class io.flutter.view.FlutterCallbackInformation { *; }
  # 保留所有带vm:entry-point注解的方法
  -keepclassmembers class * {
    @pragma('vm:entry-point') <methods>;
  }
  

• 验证后台初始化逻辑：确保初始化telephony时，正确传入后台回调函数，且回调为顶级函数（或静态方法），示例：

  final Telephony telephony = Telephony.instance;
  
  void main() {
    runApp(const MyApp());
    telephony.listenIncomingSms(
      onNewMessage: (SmsMessage message) {
        // 前台短信处理
      },
      onBackgroundMessage: backgroundMessageHandler, // 传入顶级回调函数
    );
  }
  

• 检查Flutter版本兼容性：部分旧版Flutter在Release模式下对后台入口的处理存在bug，建议升级到最新稳定版Flutter。

• 关闭电池优化：部分安卓系统会在后台杀死进程，导致广播接收器无法正常触发，需引导用户关闭应用的电池优化权限。

内容的提问来源于stack exchange，提问作者Sayam Sarkar