Question

我正在使用Android studio 3.0 beta 9来构建apk。但是最近我遇到了当我在模拟器或真实设备上通过 adb install 运行apk时，它会弹出 ClassNotFoundException ，在dexPathList中找不到应用程序类.....

但是当我通过Android Studio运行时，它运行正常。不知道是什么原因？

以下是错误日志： -

E/AndroidRuntime: FATAL EXCEPTION: main
                  Process: com.example.demo, PID: 27637
                  java.lang.RuntimeException: Unable to instantiate application
com.example.demo.MyApplication:java.lang.ClassNotFoundException: Didn't find class "com.example.demo.MyApplication" on path: DexPathList[[zip file "/data/app/com.example.demo-1/base.apk"],nativeLibraryDirectories=[/data/app/com.example.demo-1/lib/arm, /data/app/com.example.demo-1/base.apk!/lib/armeabi-v7a, /vendor/lib, /system/lib]]
at android.app.LoadedApk.makeApplication(LoadedApk.java:680)
                                                                         at android.app.ActivityThread.handleBindApplication(ActivityThread.java:6429)
                                                                         at android.app.ActivityThread.access$1800(ActivityThread.java:229)
                                                                         at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1898)
                                                                         at android.os.Handler.dispatchMessage(Handler.java:102)
                                                                         at android.os.Looper.loop(Looper.java:148)
                                                                         at android.app.ActivityThread.main(ActivityThread.java:7402)
                                                                         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.demo.MyApplication" on path: DexPathList[[zip file "/data/app/com.example.demo-1/base.apk"],nativeLibraryDirectories=[/data/app/com.example.demo-1/lib/arm, /data/app/com.example.demo-1/base.apk!/lib/armeabi-v7a, /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:1005)
                                                                         at android.app.LoadedApk.makeApplication(LoadedApk.java:670)
                                                                         at android.app.ActivityThread.handleBindApplication(ActivityThread.java:6429) 
                                                                         at android.app.ActivityThread.access$1800(ActivityThread.java:229) 
                                                                         at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1898) 
                                                                         at android.os.Handler.dispatchMessage(Handler.java:102) 
                                                                         at android.os.Looper.loop(Looper.java:148) 
                                                                         at android.app.ActivityThread.main(ActivityThread.java:7402) 
                                                                         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.demo.MyApplication
                                                                         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

Answer 1

这是因为你的程序最小化。因此，要么编辑您的proguard属性并排除您的类，请为release apk

禁用proguard

在build.gradle将minifyEnabled属性设置为false，以便在release apk中停用该程序。

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

    }

Answer 2

我终于得到了答案，有两个问题，第一个是提到的 here，当我在Android设备上直接运行应用程序时，我试图在Android上安装adb安装。

提到了第二个问题here

因此，当我尝试通过构建gradle任务构建apk时，它显示错误： -

Error:Failed to complete Gradle execution.

Cause:
The version of Gradle you are using (3.3) does not support the forTasks() method on BuildActionExecuter. Support for this is available in Gradle 3.5 and all later versions.

因此我将Gradle版本升级到最新版本并解决了问题。

通过adb install安装apk时，Application类会发生ClassNotFoundException，但在运行android studio时工作正常

2 个答案: