Android Unity 插件 - 未找到类异常

Question

我想导出一个 android 库到 Unity，但是 Android 给出了以下错误:

05-14 12:58:10.601 18408-18408/? E/AndroidRuntime: FATAL EXCEPTION: main
                                               Process: com.joostverbraeken.weargame, PID: 18408
                                               java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.joostverbraeken.weargame/com.joostverbraeken.weargame.MainActivity}: java.lang.ClassNotFoundException: Didn't find class "com.joostverbraeken.weargame.MainActivity" on path: DexPathList[[zip file "/data/app/com.joostverbraeken.weargame-1/base.apk"],nativeLibraryDirectories=[/data/app/com.joostverbraeken.weargame-1/lib/arm, /data/app/com.joostverbraeken.weargame-1/base.apk!/lib/armeabi-v7a, /vendor/lib, /system/lib]]
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2332)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2481)
at android.app.ActivityThread.access$900(ActivityThread.java:153)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1349)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5436)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:735)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:625)
                                                    Caused by: java.lang.ClassNotFoundException: Didn't find class "com.joostverbraeken.weargame.MainActivity" on path: DexPathList[[zip file "/data/app/com.joostverbraeken.weargame-1/base.apk"],nativeLibraryDirectories=[/data/app/com.joostverbraeken.weargame-1/lib/arm, /data/app/com.joostverbraeken.weargame-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.newActivity(Instrumentation.java:1068)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2322)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2481) 
at android.app.ActivityThread.access$900(ActivityThread.java:153) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1349) 
at android.os.Handler.dispatchMessage(Handler.java:102) 
at android.os.Looper.loop(Looper.java:148) 
at android.app.ActivityThread.main(ActivityThread.java:5436) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:735) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:625) 
                                                    Suppressed: java.lang.NoClassDefFoundError: com.joostverbraeken.weargame.MainActivity
at dalvik.system.DexFile.defineClassNative(Native Method)
at dalvik.system.DexFile.defineClass(DexFile.java:226)
at dalvik.system.DexFile.loadClassBinaryName(DexFile.java:219)
at dalvik.system.DexPathList.findClass(DexPathList.java:338)
at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:54)
        ... 13 more
                                                    Suppressed: java.lang.ClassNotFoundException: com.joostverbraeken.weargame.MainActivity
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 AndroidManifest(我从我的库中复制了一个到 Unity)如下:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.joostverbraeken.weargame">

    <uses-permission android:name="android.permission.WAKE_LOCK" />
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
    <uses-permission android:name="android.permission.INTERNET"/>
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>

    <application android:icon="@mipmap/ic_launcher" android:label="@string/app_name">
        <activity android:name=".MainActivity"
            android:label="@string/app_name"
            android:configChanges="fontScale|keyboard|keyboardHidden|locale|mnc|mcc|navigation|orientation|screenLayout|screenSize|smallestScreenSize|uiMode|touchscreen">
        <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

依赖关系相当简单，并在 Gradle 中声明:

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'], exclude: ['classes.jar'])
    provided files('libs/classes.jar')
    wearApp project(':wear')
    compile 'com.google.android.gms:play-services:8.4.0'
    compile 'com.android.support:support-v4:23.4.0'
}

在一个论坛上，我读到 Unity 需要将依赖项复制到 Assets/Plugins/Android 中，尽管我使用的是 aar 而不是 jar。所以我也将 support-v4-23.3.0-sources.jar 复制到 Assets/Plugins/Android 中，但是 play-services-8.4.0.jar 不是因为它不包含在 Android 系统文件中。包含 play-services-8.4.0.aar，但如果我将其复制到 Unity，则会出现以下错误:

Moving
Temp/StagingArea\android-libraries\play-services-8.4.0\classes.jar to
Temp/StagingArea\android-libraries\play-services-8.4.0\bin\classes.jar:
The system cannot find the file specified.

有人知道如何解决 ClassNotFoundException 吗？

Answer 1

我相信这是由 AndroidManifest.xml 引起的，它与 Unity 生成的 AndroidManiefst.xml 有一些冲突。在这种情况下，unity 不给我们任何错误消息是不友好的，而且只导出 eclipse 项目真的很糟糕。

我今天遇到了同样的异常，所以我做了一些进一步的测试，发现 ClassNotFoundException 只能在 Activity 类中产生。于是我导出了工程，将工程导入到AndriodStudio中重新编译。我在 AndroidManifest.xml 中遇到一些错误，例如主题不正确或图标不正确等。

在更新 AndriodManifest.xml 中所有不正确的配置并重建 AAR 后，一切正常。

希望对您有所帮助。