Android 工作应用程序上的 java.lang.ClassNotFoundException

Question

提问by Skoky

I have created and published my first Android app. It's very simple. It works fine on simulator and some phones, but I am getting this error:

我已经创建并发布了我的第一个 Android 应用程序。这很简单。它在模拟器和某些手机上运行良好，但出现此错误：

java.lang.RuntimeException: Unable to instantiate application cz.teamnovak.droid.Novak ESC Track guide: java.lang.ClassNotFoundException: cz.teamnovak.droid.Novak ESC Track guide in loader dalvik.system.PathClassLoader[/data/app/cz.teamnovak.droid-1.apk]
    at android.app.ActivityThread$PackageInfo.makeApplication(ActivityThread.java:649)
    at android.app.ActivityThread.handleBindApplication(ActivityThread.java:4232)
    at android.app.ActivityThread.access00(ActivityThread.java:125)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2071)
    at android.os.Handler.dispatchMessage(Handler.java:99)
    at android.os.Looper.loop(Looper.java:123)
    at android.app.ActivityThread.main(ActivityThread.java:4627)
    at java.lang.reflect.Method.invokeNative(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:521)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
    at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.ClassNotFoundException: cz.teamnovak.droid.Novak ESC Track guide in loader dalvik.system.PathClassLoader[/data/app/cz.teamnovak.droid-1.apk]
    at dalvik.system.PathClassLoader.findClass(PathClassLoader.java:243)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:573)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:532)
    at android.app.Instrumentation.newApplication(Instrumentation.java:942)
    at android.app.ActivityThread$PackageInfo.makeApplication(ActivityThread.java:644)
    ... 11 more

Any idea what can cause this?

知道什么会导致这种情况吗？

Answer 1

回答by phreakhead

Yep, I had this exact same problem. It was because I specified the android:nameattribute in the application node in the manifest file.

是的，我遇到了完全相同的问题。这是因为我android:name在清单文件中的应用程序节点中指定了该属性。

Your Android Manifest file probably looks something like this:

您的 Android 清单文件可能如下所示：

   <application 
       android:name="Novak ESC Track guide" 
       android:icon="@drawable/icon" 
       android:label="@string/app_name" 
       android:description="@string/help_text" >

Do not use the `android:name`attribute! unless you've implemented a custom Application object.

不要使用`android:name`属性！除非您已经实现了自定义 Application 对象。

The application:nameattribute has nothing to do with the name of your app. This is the name of a specific class to load as your Applicationinstance. That's why you would get the ClassNotFoundExceptionif that class wouldn't exist.

该application:name属性与您的应用程序名称无关。这是要作为Application实例加载的特定类的名称。这就是为什么ClassNotFoundException如果那个类不存在你会得到的原因。

For the name of the app use the `android:label`attribute on this same application node instead.

对于应用程序的名称，请改用`android:label`同一应用程序节点上的属性。

Remove it and it should work:

删除它，它应该可以工作：

<application 
    android:icon="@drawable/icon" 
    android:label="@string/app_name" 
    android:description="@string/help_text" >

Answer 2

回答by hobbs

Something like this happened when I changed the build target to 3.2. After digging around I found that a had named the jar lib folder "lib" instead of "libs". I just renamed it to libs and updated the references on the Java build path and everything was working again. Maybe this will help someone...

当我将构建目标更改为 3.2 时，发生了类似的事情。在挖掘之后，我发现 a 将 jar lib 文件夹命名为“lib”而不是“libs”。我只是将它重命名为 libs 并更新了 Java 构建路径上的引用，一切又恢复了。也许这会帮助某人......

Answer 3

回答by Alex

We have a couple of projects where this issue was logged from time to time on the Android Market. I found the following issues in the manifests:

我们有几个项目不时在 Android Market 上记录此问题。我在清单中发现了以下问题：

If the package name is com.test then activities names should be .ActivityName(with a leading dot), not just ActivityName.
For some classes, those that appeared in the logs most often, the class name was specified as com.test.Namewhile it should have been .Name.

如果包名称是 com.test 那么活动名称应该是.ActivityName（带前导点），而不仅仅是ActivityName.
对于某些类，那些最常出现在日志中的类，类名被指定为com.test.Name应该是.Name。

I guess many implementations of Android handle these minor issues successfully (this is why the exception never happened in testing), while others few are throwing the exception.

我猜 Android 的许多实现都成功地处理了这些小问题（这就是为什么在测试中从未发生异常的原因），而其他很少有人抛出异常。

Answer 4

回答by Mr G

Had the same error: java.lang.RuntimeException: Unable to instantiate activity (classnotfound) FIRST try to change the build platform (2.3.3 -> 2.2 -> 2.3.3) worked for me.

有同样的错误：java.lang.RuntimeException：无法实例化活动（classnotfound）首先尝试更改为我工作的构建平台（2.3.3 -> 2.2 -> 2.3.3）。

Answer 5

回答by lakshman

This is my observation with respect to the Error. I recently Updated the ADT to 22.0.1. I am getting following Error when i imported my previous Projects "E/AndroidRuntime(24807): Caused by: java.lang.ClassNotFoundException: com.sherl.sherlockfragmentsapp.StartActivity in loader dalvik.system.PathClassLoader[/data/app/com.sherl.sherlockfragmentsapp-1.apk]"

这是我对错误的观察。我最近将 ADT 更新到 22.0.1。当我导入以前的项目 “E/AndroidRuntime(24807): Caused by: java.lang.ClassNotFoundException: com.sherl.sherlockfragmentsapp.StartActivity in loader dalvik.system.PathClassLoader[/data/app/com. sherl.sherlockfragmentsapp-1.apk]"

Then I changed "Properties->Java Build Path-> Order and Export" in the following manner [Unable to add the Image because of the Forum rules]

然后我按照以下方式更改了“属性-> Java构建路径->顺序和导出”[由于论坛规则，无法添加图像]

Android Private Libraries - checked
Android 4.2.2 - unchecked
Android Dependencies - checked
/src - selected
/gen - selected

Android 私有库 - 选中
Android 4.2.2 - 未选中
Android 依赖项 - 已检查
/src - 选中
/gen - 选中

It resolved the issue. Hope this is Help you guys.

它解决了这个问题。希望这对你们有帮助。

Answer 6

回答by RightHandedMonkey

I have this problem sometimes with eclipse. What has corrected it for me is to go to Project Properties / Android and change the build target API to a different version and republish. I'll find that corrected it, then I can change it back to the desired build target.

我有时会遇到这个问题。对我来说更正的是转到项目属性/Android 并将构建目标 API 更改为不同的版本并重新发布。我会发现它已更正，然后我可以将其更改回所需的构建目标。

or

或者

You may need to check your proguard.cfg.

您可能需要检查您的proguard.cfg。

Assuming you have linked your libraries properly and that your library projects have the code you need marked for export, the next step you might want to do is to check your proguard settings and make sure you are not stripping out the classes you need.

假设您已正确链接您的库并且您的库项目具有您需要标记为导出的代码，您可能想要做的下一步是检查您的 proguard 设置并确保您没有删除您需要的类。

I was struggling with this quite a bit after I had my app working going directly to the emulator or device from eclipse. The problem I was having was after the app was published (i.e. gone through proguard) and run on the device it was missing classes that were contained in the project. They were being stripped out somehow.

在我的应用程序直接从 eclipse 运行到模拟器或设备后，我为此苦苦挣扎。我遇到的问题是在应用程序发布（即通过 proguard）并在设备上运行后，它缺少项目中包含的类。他们不知何故被剥夺了。

My problem may have been caused when I had tried to use IntelliJ and have switched back to eclipse.

我的问题可能是在我尝试使用 IntelliJ 并切换回 eclipse 时引起的。

Here is the proguard file that worked for me:

这是对我有用的 proguard 文件：

-optimizationpasses 5
-dontusemixedcaseclassnames
-dontskipnonpubliclibraryclasses
-dontpreverify
-verbose
-optimizations !code/simplification/arithmetic,!field/*,!class/merging/*

-keep public class * extends android.app.Activity
-keep public class * extends android.app.Application
-keep public class * extends android.app.Service
-keep public class * extends android.content.BroadcastReceiver
-keep public class * extends android.content.ContentProvider
-keep public class * extends android.app.backup.BackupAgentHelper
-keep public class * extends android.preference.Preference
-keep public class com.android.vending.licensing.ILicensingService

-keepclasseswithmembers class * {
    native <methods>;
}

-keepclasseswithmembers class * {
    public <init>(android.content.Context, android.util.AttributeSet);
}

-keepclasseswithmembers class * {
    public <init>(android.content.Context, android.util.AttributeSet, int);
}

-keepclassmembers enum * {
    public static **[] values();
    public static ** valueOf(java.lang.String);
}

-keep class * implements android.os.Parcelable {
  public static final android.os.Parcelable$Creator *;
}

Answer 7

回答by Logan

I got this error when I ran my app on earlier versions of android. I thought SearchViewwas backwards compatible to Android 1.5, but it was created in 3.0. I removed its reference from the code and it worked.

当我在早期版本的 android 上运行我的应用程序时出现此错误。我认为SearchView向后兼容 Android 1.5，但它是在 3.0 中创建的。我从代码中删除了它的引用并且它起作用了。

Answer 8

回答by icyerasor

Had this sort of problem today after upgrading to latest ADT/SDK. Took me quite a while. Checked that i used google-apis (for maps), uses-library, cleaned the project etc.

升级到最新的 ADT/SDK 后今天遇到了这种问题。花了我很长时间。检查我是否使用了 google-apis（用于地图）、uses-library、清理项目等。

Deleting the .project and adding a fresh one (create new android project) finally solved it.

删除 .project 并添加一个新的（创建新的 android 项目）终于解决了它。

Answer 9

回答by Joel Martinez

I know this question has been answered, and it likely wasn't the case. But I was getting this error, and figured I'd post why in case it can be helpful to anyone else.

我知道这个问题已经得到了回答，但情况可能并非如此。但是我遇到了这个错误，我想我会发布原因，以防它对其他人有帮助。

So I was getting this error, and after several hours sheepishly realized that I had unchecked 'Project > Build Automatically'. So although I had no compilation errors, this is why I was getting this error. Everything started working as soon as I realized that I wasn't actually building the project before deploying :-/

所以我收到了这个错误，几个小时后羞怯地意识到我没有选中“项目>自动构建”。因此，虽然我没有编译错误，但这就是我收到此错误的原因。当我意识到我实际上并没有在部署之前构建项目时，一切都开始工作了：-/

Well, that's my story :-)

好吧，这就是我的故事:-)

Answer 10

回答by lost_bits1110

Make sure that android:hasCodeis not set to falsein your manifest file. This is what solved the problem for me!

确保android:hasCode未false在清单文件中设置为。这就是为我解决问题的原因！

Android 工作应用程序上的 java.lang.ClassNotFoundException

提问by Skoky

回答by phreakhead

Do not use the `android:name`attribute! unless you've implemented a custom Application object.

不要使用`android:name`属性！除非您已经实现了自定义 Application 对象。

For the name of the app use the `android:label`attribute on this same application node instead.

对于应用程序的名称，请改用`android:label`同一应用程序节点上的属性。

回答by hobbs

回答by Alex

回答by Mr G

回答by lakshman

回答by RightHandedMonkey

回答by Logan

回答by icyerasor

回答by Joel Martinez

回答by lost_bits1110

相关推荐

最近更新

标签

Android 工作应用程序上的 java.lang.ClassNotFoundException

提问by Skoky

回答by phreakhead

Do not use the android:nameattribute! unless you've implemented a custom Application object.

不要使用android:name属性！除非您已经实现了自定义 Application 对象。

For the name of the app use the android:labelattribute on this same application node instead.

对于应用程序的名称，请改用android:label同一应用程序节点上的属性。

回答by hobbs

回答by Alex

回答by Mr G

回答by lakshman

回答by RightHandedMonkey

回答by Logan

回答by icyerasor

回答by Joel Martinez

回答by lost_bits1110

相关推荐

Android：有什么比 android:ellipsize="end" 更好的方法来添加 "..." 到截断的长字符串？

Android Circular Determinate ProgressBar

Android 在我的应用程序中禁用多指触摸

Android ICS 上的 ACCESS_NETWORK_STATE 权限

相关推荐

最近更新

标签

Do not use the `android:name`attribute! unless you've implemented a custom Application object.

不要使用`android:name`属性！除非您已经实现了自定义 Application 对象。

For the name of the app use the `android:label`attribute on this same application node instead.

对于应用程序的名称，请改用`android:label`同一应用程序节点上的属性。