Android Studio导入含JNI代码的.AAR文件失败求助

问题背景 #

我给Android项目添加了一个包含JNI代码的AAR依赖，具体操作是在app模块的build.gradle中添加：

implementation files('libs/rustsdk/matrix-rust-sdk.aar')

其中libs/rustsdk是app目录下的子文件夹。项目可以正常导入和编译，但在模拟器运行时直接崩溃，抛出以下致命错误：

E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.example.myapplication, PID: 2138
    java.lang.NoClassDefFoundError: Failed resolution of: Lcom/sun/jna/Structure;
        at com.example.myapplication.MainActivity.onCreate(MainActivity.kt:22)
        at android.app.Activity.performCreate(Activity.java:8000)
        at android.app.Activity.performCreate(Activity.java:7984)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1309)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3422)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3601)
        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:85)
        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2066)
        at android.os.Handler.dispatchMessage(Handler.java:106)
        at android.os.Looper.loop(Looper.java:223)
        at android.app.ActivityThread.main(ActivityThread.java:7656)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)
     Caused by: java.lang.ClassNotFoundException: Didn't find class "com.sun.jna.Structure" on path: DexPathList[[zip file "/data/app/~~3uqrtfBdNI7R0W86fLWX8w==/com.example.myapplication-xpIJTty5zNLizFxpMQy-kw==/base.apk"],nativeLibraryDirectories=[/data/app/~~3uqrtfBdNI7R0W86fLWX8w==/com.example.myapplication-xpIJTty5zNLizFxpMQy-kw==/lib/x86, /data/app/~~3uqrtfBdNI7R0W86fLWX8w==/com.example.myapplication-xpIJTty5zNLizFxpMQy-kw==/base.apk!/lib/x86, /system/lib, /system_ext/lib]]
        at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:207)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:379)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:312)
        at com.example.myapplication.MainActivity.onCreate(MainActivity.kt:22) 
        at android.app.Activity.performCreate(Activity.java:8000) 
        at android.app.Activity.performCreate(Activity.java:7984) 
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1309) 
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3422) 
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3601) 
        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:85) 
        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135) 
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95) 
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2066) 
        at android.os.Handler.dispatchMessage(Handler.java:106) 
        at android.os.Looper.loop(Looper.java:223) 
        at android.app.ActivityThread.main(ActivityThread.java:7656) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947) 
I/Process: Sending signal. PID: 2138 SIG: 9
Disconnected from the target VM, address: 'localhost:43017', transport: 'socket'

额外信息：

• 该AAR文件包含JNI相关的多架构so文件、classes.jar等内容
• 对比其他使用该AAR的项目，发现他们编译后libs/rustsdk目录会生成build文件夹，但我的项目没有
• 已尝试过常见教程中的步骤，问题仍未解决

当前app模块的build.gradle代码如下：

plugins {
    id 'com.android.application'
    id 'org.jetbrains.kotlin.android'
}

android {
    namespace 'com.example.myapplication'
    compileSdk 33

    defaultConfig {
        applicationId "com.example.myapplication"
        minSdk 26
        targetSdk 33
        versionCode 1
        versionName "1.0"

        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
        vectorDrawables {
            useSupportLibrary true
        }
    }

    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }
    kotlinOptions {
        jvmTarget = '1.8'
    }
    buildFeatures {
        compose true
    }
    composeOptions {
        kotlinCompilerExtensionVersion '1.2.0'
    }
    packagingOptions {
        resources {
            excludes += '/META-INF/{AL2.0,LGPL2.1}'
        }
    }
}

dependencies {
    implementation fileTree(dir: "libs", include: ["*.jar", "*.aar"])

    implementation 'androidx.core:core-ktx:1.7.0'
    implementation 'androidx.lifecycle:lifecycle-runtime-ktx:2.3.1'
    implementation 'androidx.activity:activity-compose:1.3.1'
    implementation "androidx.compose.ui:ui:$compose_version"
    implementation "androidx.compose.ui:ui-tooling-preview:$compose_version"
    implementation 'androidx.compose.material3:material3:1.0.0-alpha11'
    implementation files('libs/rustsdk/matrix-rust-sdk.aar')
    testImplementation 'junit:junit:4.13.2'
    androidTestImplementation 'androidx.test.ext:junit:1.1.5'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.5.1'
    androidTestImplementation "androidx.compose.ui:ui-test-junit4:$compose_version"
    debugImplementation "androidx.compose.ui:ui-tooling:$compose_version"
    debugImplementation "androidx.compose.ui:ui-test-manifest:$compose_version"
}

解决方案 #

这个错误的核心原因是你引入的AAR依赖了JNA（Java Native Access）库，但你的项目没有添加JNA的依赖，导致运行时找不到com.sun.jna.Structure类。

步骤1：添加JNA依赖 #

在app模块的build.gradle的dependencies块中添加JNA的依赖：

implementation 'net.java.dev.jna:jna:5.13.0'
implementation 'net.java.dev.jna:jna-platform:5.13.0'

版本号可以根据AAR实际依赖的版本调整，如果不确定，使用较新的稳定版本即可。

步骤2：清理并重新构建项目 #

1. 执行File -> Invalidate Caches... -> Invalidate and Restart清理缓存并重启Android Studio
2. 执行Build -> Clean Project清理项目
3. 执行Build -> Rebuild Project重新构建项目

额外说明 #

关于libs/rustsdk目录没有生成build文件夹的问题，这是因为其他项目可能将该目录作为子模块或独立的构建单元处理，而你的项目只是将AAR作为本地文件依赖，不需要生成该目录的build文件夹，这个不是导致当前崩溃的原因。

内容的提问来源于stack exchange，提问作者carmius