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

Question

如果出现此问题：

我运行来自 Android Studio 的应用程序，该应用程序运行s 正确

然后我删除了应用程序并尝试从 .../app/build/outputs/apk/debug.apk
安装 debug.apk

我的OS是Ubuntu16.04，oraclejdk

但在 Windows 7 上一切正常（apk 可以从 .../app/build/outputs/apk/debug.apk 和运行s 正确安装）

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.access00(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.access00(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gradle:

    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。应用只有从 Android Studio 安装时才能运行，如果通过 adb 命令安装则崩溃。使 caches/Restart 无效并禁用 Instant 运行(Android Studio->Preferences->Instant 运行, 取消选中 "Enable Instance Run") 在我的情况下有效。

Answer 2

我只想说我知道这真的很愚蠢而且我知道这个问题已经得到解答但是我更改了我的应用程序的名称 class 但出于某种原因忘记在清单中更改它该应用程序仍在构建中。无论如何，请确保您的项目清单中的应用 class 名称正确：

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

Answer 3

在应用级别添加 multidex gradle

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

启用 multidex

 defaultConfig {
 multiDexEnabled true
}

最后在应用程序中添加此代码 class

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

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 manifest 文件中，只需将 allowBackup 更改为 false。
然后运行应用程序，你会得到一个异常。
然后将其改回 true，这将完全修复它。

Answer 5

将此添加到 gradle 对我有帮助

compileOptions {
    sourceCompatibility JavaVersion.VERSION_1_8
    targetCompatibility JavaVersion.VERSION_1_8
}

Answer 6

如果你有API20级以上的测试设备，你可以将你的minSdkVersion改为21，而不是添加multidex，因为API20级及以上有multidex

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

Unable to instantiate application: java.lang.ClassNotFoundException:

java

android

ubuntu-16.04