Question

如果出现以下问题：

我从Android Studio运行应用，应用正常运行

然后我删除该应用并尝试从.../app/build/outputs/apk/debug.apk安装debug.apk

我的操作系统是Ubuntu 16.04，oracle jdk

但在Windows 7上一切正常（apk可以从.../app/build/outputs/apk/debug.apk安装并正常运行）

发生此错误：

FATAL EXCEPTION: main
Process: com.example, PID: 21084
java.lang.RuntimeException: Unable to instantiate application com.example.MyApp: java.lang.ClassNotFoundException: Didn't find class "com.example.MyApp" on path: DexPathList[[zip file "/data/app/com.example-1/base.apk"],nativeLibraryDirectories=[/data/app/com.example-1/lib/arm, /vendor/lib, /system/lib]]
at android.app.LoadedApk.makeApplication(LoadedApk.java:676)
at android.app.ActivityThread.handleBindApplication(ActivityThread.java:6289)
at android.app.ActivityThread.access$1800(ActivityThread.java:221)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1860)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:158)
at android.app.ActivityThread.main(ActivityThread.java:7224)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)
Caused by: java.lang.ClassNotFoundException: Didn't find class "com.example.MyApp" on path: DexPathList[[zip file "/data/app/com.example-1/base.apk"],nativeLibraryDirectories=[/data/app/com.example-1/lib/arm, /vendor/lib, /system/lib]]
at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
at java.lang.ClassLoader.loadClass(ClassLoader.java:511)
at java.lang.ClassLoader.loadClass(ClassLoader.java:469)
at android.app.Instrumentation.newApplication(Instrumentation.java:1004)
at android.app.LoadedApk.makeApplication(LoadedApk.java:666)
at android.app.ActivityThread.handleBindApplication(ActivityThread.java:6289) 
at android.app.ActivityThread.access$1800(ActivityThread.java:221) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1860) 
at android.os.Handler.dispatchMessage(Handler.java:102) 
at android.os.Looper.loop(Looper.java:158) 
at android.app.ActivityThread.main(ActivityThread.java:7224) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120) 
Suppressed: java.lang.ClassNotFoundException: com.example.MyApp
at java.lang.Class.classForName(Native Method)
at java.lang.BootClassLoader.findClass(ClassLoader.java:781)
at java.lang.BootClassLoader.loadClass(ClassLoader.java:841)
at java.lang.ClassLoader.loadClass(ClassLoader.java:504)
        ... 12 more
Caused by: java.lang.NoClassDefFoundError: Class not found using the boot class loader; no stack trace available

我的傻瓜：

    apply plugin: 'com.android.application'
apply plugin: 'me.tatarka.retrolambda'
apply plugin: 'io.fabric'
apply plugin: 'android-apt'

android {
    compileSdkVersion 25
    buildToolsVersion "25.0.2"

defaultConfig {
    applicationId "com.example"
    minSdkVersion 19
    targetSdkVersion 25
    versionCode 1
    versionName "1.0"

    multiDexEnabled true
    testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    jackOptions {
        enabled false
    }
}

compileOptions {
    sourceCompatibility JavaVersion.VERSION_1_8
    targetCompatibility JavaVersion.VERSION_1_8
}

dexOptions {
    javaMaxHeapSize "8g"
    jumboMode = true
    preDexLibraries = false
}

signingConfigs {
    //release
    release {
        storeFile file("/keys/apk_key.jks")
        storePassword "apk_key"
        keyAlias "apk_key"
        keyPassword "apk_key"
    }
}

buildTypes {
    release {
        minifyEnabled false
        proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        signingConfig signingConfigs.release
        debuggable false
    }
    debug {
        signingConfig signingConfigs.release
        debuggable true
    }
}

dexOptions {
    javaMaxHeapSize "3G"
}

packagingOptions {
    exclude 'LICENSE.txt'
    exclude 'mockito-extensions/org.mockito.plugins.MockMaker'
    exclude 'META-INF/DEPENDENCIES.txt'
    exclude 'META-INF/LICENSE.txt'
    exclude 'META-INF/NOTICE.txt'
    exclude 'META-INF/NOTICE'
    exclude 'META-INF/LICENSE'
    exclude 'META-INF/DEPENDENCIES'
    exclude 'META-INF/notice.txt'
    exclude 'META-INF/license.txt'
    exclude 'META-INF/dependencies.txt'
}

}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    ...
}

我也尝试过：

Invalidate Cache/Restart
Clean Project
Rebuild project

Answer 1

谢谢@Dileep Patel 我遇到了同样的问题。应用程序仅在从Android Studio安装时才有效，如果由adb命令安装则崩溃。无效缓存/重新启动和禁用即时运行（Android Studio-＆gt;首选项 - ＆gt;即时运行，取消选中＆＃34;启用实例运行＆＃34;）在我的案例中有效。

Answer 2

在app level gradle中添加multidex

compile 'com.android.support:multidex:1.0.1'

启用multidex

 defaultConfig {
 multiDexEnabled true
}

最后在应用程序类

中添加此代码

 @Override
    protected void attachBaseContext(Context base) {
        super.attachBaseContext(base);
        MultiDex.install(this);
    }

Answer 3

我只想说，我知道这真的很愚蠢，我知道这个问题已经得到了解答，但是我更改了我的App类的名称而忘记在清单中更改它，因为某些原因应用程序仍然构建。无论如何，请确保在项目清单中有正确的app类名称：

    <application
    android:name=".CorrectAppClassHere"
        //...

Answer 4

<application
            android:name=".App"
            android:allowBackup="true"
            android:icon="@mipmap/ic_launcher"
            android:label="@string/app_name"
            android:roundIcon="@mipmap/ic_launcher_round"
            android:supportsRtl="true"
            android:theme="@style/AppTheme">

在您的清单文件中，只需将allowBackup更改为 false 。
然后运行该应用程序，您将得到一个异常。
然后将其更改回 true ，即可完全修复该问题。

Answer 5

将此添加到gradle中对我有帮助

compileOptions {
    sourceCompatibility JavaVersion.VERSION_1_8
    targetCompatibility JavaVersion.VERSION_1_8
}

Answer 6

如果您的测试设备的API级别为20以上，则可以将minSdkVersion更改为21，而不是添加multidex，因为API级别20及更高版本中包含multidex。

无法实例化应用程序：java.lang.ClassNotFoundException：

6 个答案: