引起：java.lang.ClassNotFoundException：在任何原子类加载器或父类加载器中找不到

Question

我正在尝试对 Instant Apps 文档进行一些实验：Android Instant Apps Native Android apps, without the installation. 我已按照官方文档中介绍的步骤进行操作。我创建了模拟器 Nexus 5X 来测试即时应用功能。

所以，我在我的项目中创建了两个功能，它们非常相似，只是一个演示，以了解即时应用程序的工作原理。它在一项功能上运行良好，现在当我创建另一个功能后，现在我有两个功能依次使我的应用程序崩溃。

05-24 12:07:12.259 12020-12028/? E/art: Failed writing handshake bytes (-1 of 14): Broken pipe
05-24 12:07:15.952 12020-12020/com.williams.instantappdemo E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.williams.instantappdemo, PID: 12020
java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.williams.instantappdemo/com.williams.instantappdemo.feature.MainActivity}: java.lang.ClassNotFoundException: could not find com.williams.instantappdemo.feature.MainActivity in any atom class loader or parent class loader
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2567)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2726)
    at android.app.ActivityThread.-wrap12(ActivityThread.java)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1477)
    at android.os.Handler.dispatchMessage(Handler.java:102)
    at android.os.Looper.loop(Looper.java:154)
    at android.app.ActivityThread.main(ActivityThread.java:6119)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)
 Caused by: java.lang.ClassNotFoundException: could not find com.williams.instantappdemo.feature.MainActivity in any atom class loader or parent class loader
    at com.google.android.instantapps.supervisor.loader.WhAppClassLoader.loadClass(WhAppClassLoader.java:100)
    at android.app.Instrumentation.newActivity(Instrumentation.java:1078)
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2557)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2726) 
    at android.app.ActivityThread.-wrap12(ActivityThread.java) 
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1477) 
    at android.os.Handler.dispatchMessage(Handler.java:102) 
    at android.os.Looper.loop(Looper.java:154) 
    at android.app.ActivityThread.main(ActivityThread.java:6119) 
    at java.lang.reflect.Method.invoke(Native Method) 
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886) 
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776) 
    Suppressed: java.lang.ClassNotFoundException: Didn't find class "com.williams.instantappdemo.feature.MainActivity" on path: DexPathList[[directory "."],nativeLibraryDirectories=[/system/lib, /vendor/lib, /system/lib, /vendor/lib]]
    at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:380)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:312)
    at com.google.android.instantapps.supervisor.loader.WhAppClassLoader.loadClass(WhAppClassLoader.java:85)
            ... 11 more
    Suppressed: java.lang.ClassNotFoundException: Didn't find class "com.williams.instantappdemo.feature.MainActivity" on path: DexPathList[[zip file "/data/user/0/com.google.android.instantapps.supervisor/files/atom-cache/com.williams.instantappdemo/atom-download--base-1495607829279/base.jar"],nativeLibraryDirectories=[/data/user/0/com.google.android.instantapps.supervisor/files/native-lib/com.williams.instantappdemo, /system/lib, /vendor/lib]]
    at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
    at com.google.android.instantapps.supervisor.loader.DexFirstClassLoader.doLoadClass(DexFirstClassLoader.java:50)
    at com.google.android.instantapps.supervisor.loader.WhAppClassLoader.loadClass(WhAppClassLoader.java:92)
            ... 11 more
    Suppressed: java.lang.ClassNotFoundException: Didn't find class "com.williams.instantappdemo.feature.MainActivity" on path: DexPathList[[zip file "/data/user/0/com.google.android.instantapps.supervisor/files/atom-cache/com.williams.instantappdemo/atom-download--feature-1495607829279/feature.jar"],nativeLibraryDirectories=[/data/user/0/com.google.android.instantapps.supervisor/files/native-lib/com.williams.instantappdemo, /system/lib, /vendor/lib]]
    at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
    at com.google.android.instantapps.supervisor.loader.DexFirstClassLoader.doLoadClass(DexFirstClassLoader.java:50)
    at com.google.android.instantapps.supervisor.loader.WhAppClassLoader.loadClass(WhAppClassLoader.java:92)
            ... 11 more

这里是功能模块的build.gradle：

apply plugin: 'com.android.feature'

android {
    compileSdkVersion 25
    buildToolsVersion rootProject.buildToolsVersion
    defaultConfig {
        minSdkVersion 23
        targetSdkVersion 25
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    implementation project(':base')
    testCompile 'junit:junit:4.12'

}

这里是 feature2 的 build.gradle：

apply plugin: 'com.android.feature'


android {
    compileSdkVersion 25
    buildToolsVersion rootProject.buildToolsVersion


    defaultConfig {
        minSdkVersion 23
        targetSdkVersion 25
        versionCode 1
        versionName "1.0"

        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"

    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    implementation project(':base')

    testCompile 'junit:junit:4.12'
}

这是基本模块的 build.gradle：

apply plugin: 'com.android.feature'

android {
    compileSdkVersion 25
    buildToolsVersion rootProject.buildToolsVersion
    baseFeature true
    defaultConfig {
        minSdkVersion 23
        targetSdkVersion 25
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    feature project(':feature')
    compile 'com.android.support:appcompat-v7:25.+'
    compile 'com.android.support.constraint:constraint-layout:1.0.2'
    feature project(":feature1")
}

这是应用模块的build.gradle：

apply plugin: 'com.android.application'

android {
    compileSdkVersion 25
    buildToolsVersion rootProject.buildToolsVersion


    defaultConfig {
        applicationId "com.nagarro.instantappdemo"
        minSdkVersion 23
        targetSdkVersion 25
        versionCode 1
        versionName "1.0"


    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation project(':feature')
    implementation project(':feature1')
    implementation project(':base')
}

谁能建议我做错了什么？

Answer 1

看起来实际的活动包与您在包含 MainActivity 的功能的清单文件中的内容不匹配。在将活动重构到新包中并且未对清单中的活动使用相对路径时，这是一个常见错误。完全限定路径以绝对确定

 <activity android:name="com.williams.instantappdemo.feature.MainActivity"/>

使用Apk Analyzer 检查apk 文件（build/outputs/apks），看看它是否在那个确切的包中包含com.williams.instantappdemo.feature.MainActivity。

您还可以使用Merged Manifest view 检查您的最终清单（应用程序模块），以验证一切正常。

另外，将 application project(":app") 添加到基本功能模块，以便它使用您的应用模块中定义的 applicationId 来打包您的应用/即时应用

更新： 使用上述技术，我调查了合并的清单并发现了一个问题。构建插件忽略了模块名称 (feature1) 中的数字，因此这两个功能最终具有相同的名称。这导致了一系列问题，包括 ActivityNotFound 错误。将 feature1 模块重命名为 featureOne 解决了该问题。