java.lang.ClassNotFoundException：在路径上找不到 class “eduapp.arg.MainApplication”：DexPathList

Question

这是一个 react native 应用程序，首先使用 expo 然后弹出。 当我想执行构建时，它不会给出任何错误，但是在安装和运行它时会崩溃，应用程序永远不会立即关闭并显示错误。

使用 adb logcat 工具查看电话日志并向我显示：

Unable to instantiate application eduapp.arg.MainApplication: java.lang.ClassNotFoundException: Didn't find class "eduapp.arg.MainApplication" on path: DexPathList

08-07 02:32:48.585 10182 10182 E AndroidRuntime: FATAL EXCEPTION: main
08-07 02:32:48.585 10182 10182 E AndroidRuntime: Process: eduapp.arg, PID: 10182
08-07 02:32:48.585 10182 10182 E AndroidRuntime: java.lang.RuntimeException: Unable to instantiate application eduapp.arg.MainApplication: java.lang.ClassNotFoundException: Didn't find class "eduapp.arg.MainApplication" on path: DexPathList[[zip file "/data/app/eduapp.arg-FAa3-QgPlP0Ej-TLlvTegw==/base.apk"],nativeLibraryDirectories=[/data/app/eduapp.arg-FAa3-QgPlP0Ej-TLlvTegw==/lib/arm64, /data/app/eduapp.arg-FAa3-QgPlP0Ej-TLlvTegw==/base.apk!/lib/arm64-v8a, /system/lib64]]
08-07 02:32:48.585 10182 10182 E AndroidRuntime:        at android.app.LoadedApk.makeApplication(LoadedApk.java:1073)
08-07 02:32:48.585 10182 10182 E AndroidRuntime:        at android.app.ActivityThread.handleBindApplication(ActivityThread.java:5920)
08-07 02:32:48.585 10182 10182 E AndroidRuntime:        at android.app.ActivityThread.access$1200(ActivityThread.java:200)
08-07 02:32:48.585 10182 10182 E AndroidRuntime:        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1673)
08-07 02:32:48.585 10182 10182 E AndroidRuntime:        at android.os.Handler.dispatchMessage(Handler.java:106)
08-07 02:32:48.585 10182 10182 E AndroidRuntime:        at android.os.Looper.loop(Looper.java:201)
08-07 02:32:48.585 10182 10182 E AndroidRuntime:        at android.app.ActivityThread.main(ActivityThread.java:6810)
08-07 02:32:48.585 10182 10182 E AndroidRuntime:        at java.lang.reflect.Method.invoke(Native Method)
08-07 02:32:48.585 10182 10182 E AndroidRuntime:        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:547)
08-07 02:32:48.585 10182 10182 E AndroidRuntime:        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:873)
08-07 02:32:48.585 10182 10182 E AndroidRuntime: Caused by: java.lang.ClassNotFoundException: Didn't find class "eduapp.arg.MainApplication" on path: DexPathList[[zip file "/data/app/eduapp.arg-FAa3-QgPlP0Ej-TLlvTegw==/base.apk"],nativeLibraryDirectories=[/data/app/eduapp.arg-FAa3-QgPlP0Ej-TLlvTegw==/lib/arm64, /data/app/eduapp.arg-FAa3-QgPlP0Ej-TLlvTegw==/base.apk!/lib/arm64-v8a, /system/lib64]]
08-07 02:32:48.585 10182 10182 E AndroidRuntime:        at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:134)
08-07 02:32:48.585 10182 10182 E AndroidRuntime:        at java.lang.ClassLoader.loadClass(ClassLoader.java:379)
08-07 02:32:48.585 10182 10182 E AndroidRuntime:        at java.lang.ClassLoader.loadClass(ClassLoader.java:312)
08-07 02:32:48.585 10182 10182 E AndroidRuntime:        at android.app.AppComponentFactory.instantiateApplication(AppComponentFactory.java:50)
08-07 02:32:48.585 10182 10182 E AndroidRuntime:        at androidx.core.app.CoreComponentFactory.instantiateApplication(CoreComponentFactory.java:47)
08-07 02:32:48.585 10182 10182 E AndroidRuntime:        at android.app.Instrumentation.newApplication(Instrumentation.java:1121)
08-07 02:32:48.585 10182 10182 E AndroidRuntime:        at android.app.LoadedApk.makeApplication(LoadedApk.java:1065)
08-07 02:32:48.585 10182 10182 E AndroidRuntime:        ... 9 more
08-07 02:32:48.591  2038  3384 W ActivityManager:   Force finishing activity eduapp.arg/.MainActivity

亚行日志

这里我留下 Android Manifest.xml

<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="eduapp.arg">
  <uses-permission android:name="android.permission.INTERNET"/>
  <uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW"/>
  <uses-permission android:name="android.permission.MANAGE_DOCUMENTS"/>
  <uses-permission android:name="android.permission.READ_INTERNAL_STORAGE"/>
  <uses-permission android:name="android.permission.READ_PHONE_STATE"/>
  <uses-permission android:name="android.permission.USE_FINGERPRINT"/>
  <uses-permission android:name="android.permission.VIBRATE"/>
  <uses-permission android:name="android.permission.MODIFY_AUDIO_SETTINGS"/>
  <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
  <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
  <uses-permission android:name="android.permission.CAMERA"/>
  <uses-permission android:name="android.permission.READ_CONTACTS"/>
  <uses-permission android:name="android.permission.READ_CALENDAR"/>
  <uses-permission android:name="android.permission.WRITE_CALENDAR"/>
  <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
  <uses-permission android:name="android.permission.RECORD_AUDIO"/>
  <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
  <uses-permission android:name="android.permission.WRITE_SETTINGS"/>
  <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
  <uses-permission android:name="android.permission.WAKE_LOCK"/>
  <uses-permission android:name="com.google.android.c2dm.permission.RECEIVE"/>
  <application android:name=".MainApplication" android:label="@string/app_name" android:icon="@mipmap/ic_launcher" android:roundIcon="@mipmap/ic_launcher_round" android:allowBackup="false" android:theme="@style/AppTheme">
    <meta-data android:name="expo.modules.updates.EXPO_UPDATE_URL" android:value="YOUR-APP-URL-HERE"/>
    <meta-data android:name="expo.modules.updates.EXPO_SDK_VERSION" android:value="37.0.0"/>
    <meta-data android:name="expo.modules.updates.ENABLED" android:value="true"/>
    <meta-data android:name="expo.modules.updates.EXPO_UPDATES_CHECK_ON_LAUNCH" android:value="ALWAYS"/>
    <meta-data android:name="expo.modules.updates.EXPO_UPDATES_LAUNCH_WAIT_MS" android:value="0"/>
    <activity android:name=".MainActivity" android:label="@string/app_name" android:configChanges="keyboard|keyboardHidden|orientation|screenSize" android:launchMode="singleTask" android:windowSoftInputMode="adjustResize" android:theme="@style/Theme.App.SplashScreen" android:screenOrientation="portrait">
      <intent-filter>
        <action android:name="android.intent.action.MAIN"/>
        <category android:name="android.intent.category.LAUNCHER"/>
      </intent-filter>
    </activity>
    <activity android:name="com.facebook.react.devsupport.DevSettingsActivity"/>
    <activity
      android:name="com.theartofdev.edmodo.cropper.CropImageActivity"
      android:theme="@style/Base.Theme.AppCompat">
    </activity>
  </application>
</manifest>

AndroidManifest

这是 MainApplication.java

package com.frontendeduapp;

import android.app.Application;
import android.content.Context;
import android.net.Uri;

import com.facebook.react.PackageList;
import com.facebook.react.ReactApplication;
import com.facebook.react.ReactNativeHost;
import com.facebook.react.ReactPackage;
import com.facebook.react.shell.MainReactPackage;
import com.facebook.soloader.SoLoader;
import com.facebook.react.BuildConfig;
import com.frontendeduapp.generated.BasePackageList;

import org.unimodules.adapters.react.ReactAdapterPackage;
import org.unimodules.adapters.react.ModuleRegistryAdapter;
import org.unimodules.adapters.react.ReactModuleRegistryProvider;
import org.unimodules.core.interfaces.Package;
import org.unimodules.core.interfaces.SingletonModule;
import expo.modules.constants.ConstantsPackage;
import expo.modules.permissions.PermissionsPackage;
import expo.modules.filesystem.FileSystemPackage;
import expo.modules.updates.UpdatesController;

import java.lang.reflect.InvocationTargetException;
import java.util.Arrays;
import java.util.List;
import javax.annotation.Nullable;

public class MainApplication extends Application implements ReactApplication {
  private final ReactModuleRegistryProvider mModuleRegistryProvider = new ReactModuleRegistryProvider(
    new BasePackageList().getPackageList()
  );

  private final ReactNativeHost mReactNativeHost = new ReactNativeHost(this) {
    @Override
    public boolean getUseDeveloperSupport() {
      return BuildConfig.DEBUG;
    }

    @Override
    protected List<ReactPackage> getPackages() {
      List<ReactPackage> packages = new PackageList(this).getPackages();
      packages.add(new ModuleRegistryAdapter(mModuleRegistryProvider));
      return packages;
    }

    @Override
    protected String getJSMainModuleName() {
      return "index";
    }

    @Override
    protected @Nullable String getJSBundleFile() {
      if (BuildConfig.DEBUG) {
        return super.getJSBundleFile();
      } else {
        return UpdatesController.getInstance().getLaunchAssetFile();
      }
    }

    @Override
    protected @Nullable String getBundleAssetName() {
      if (BuildConfig.DEBUG) {
        return super.getBundleAssetName();
      } else {
        return UpdatesController.getInstance().getBundleAssetName();
      }
    }
  };

  @Override
  public ReactNativeHost getReactNativeHost() {
    return mReactNativeHost;
  }

  @Override
  public void onCreate() {
    super.onCreate();
    SoLoader.init(this, /* native exopackage */ false);
    initializeFlipper(this); // Remove this line if you don't want Flipper enabled

    if (!BuildConfig.DEBUG) {
      UpdatesController.initialize(this);
    }
  }

  /**
   * Loads Flipper in React Native templates.
   *
   * @param context
   */
  private static void initializeFlipper(Context context) {
    if (BuildConfig.DEBUG) {
      try {
        /*
         We use reflection here to pick up the class that initializes Flipper,
        since Flipper library is not available in release mode
        */
        Class<?> aClass = Class.forName("com.facebook.flipper.ReactNativeFlipper");
        aClass.getMethod("initializeFlipper", Context.class).invoke(null, context);
      } catch (ClassNotFoundException e) {
        e.printStackTrace();
      } catch (NoSuchMethodException e) {
        e.printStackTrace();
      } catch (IllegalAccessException e) {
        e.printStackTrace();
      } catch (InvocationTargetException e) {
        e.printStackTrace();
      }
    }
  }
}

如果您想查看完整的项目，我会留下 github 链接。

https://github.com/SasePriv/FrontEnd-EduApp/tree/expo-eject

Answer 1

从日志中： Unable to instantiate application eduapp.arg.MainApplication: java.lang.ClassNotFoundException: Didn't find class "eduapp.arg.MainApplication" on path

从Android 开发人员文档中，AndroidManifest 中package属性的用途之一是：

...to resolve any relative class names that are declared in the manifest file.
For example, if package is set to "com.example.myapp", an activity declared as <activity android:name=".MainActivity"> is resolved to be com.example.myapp.MainActivity

因此，您的 MainApplication 位于 package com.frontendeduapp中，但您在 AndroidManifest 中将 package 定义为eduapp.arg 因此，现在在构建您的应用程序时， package的值用于将您的相对.MainApplication转换为eduapp.arg.MainApplication而实际上它应该是com.frontendeduapp.MainApplication 。

解决方案是在您的 AndroidManifest eduapp.arg替换为com.frontendeduapp并重建。