安卓：ClassNotFoundException的传递序列化的对象到活动时， [英] Android: ClassNotFoundException when passing serializable object to Activity

问题描述

我有几个崩溃报告日志从Android Market类似这样：

I have a few crash report logs from android market similar to this:

Exception class: java.lang.ClassNotFoundException

Source method: PathClassLoader.findClass()

java.lang.RuntimeException: Unable to start activity ComponentInfo{my.app.package/my.app.package.MyActivity}: java.lang.RuntimeException: Parcelable encounteredClassNotFoundException reading a Serializable object (name = my.app.package.a.ae)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2833)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2854)
at android.app.ActivityThread.access$2300(ActivityThread.java:136)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2179)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:143)
at android.app.ActivityThread.main(ActivityThread.java:5068)
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.RuntimeException: Parcelable encounteredClassNotFoundException reading a Serializable object (name = my.app.package.a.ae)
at android.os.Parcel.readSerializable(Parcel.java:1951)
at android.os.Parcel.readValue(Parcel.java:1822)
at android.os.Parcel.readMapInternal(Parcel.java:2008)
at android.os.Bundle.unparcel(Bundle.java:208)
at android.os.Bundle.getBundle(Bundle.java:1078)
at android.app.Activity.onRestoreInstanceState(Activity.java:861)
at android.app.Activity.performRestoreInstanceState(Activity.java:835)
at android.app.Instrumentation.callActivityOnRestoreInstanceState(Instrumentation.java:1135)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2811)
... 11 more
Caused by: java.lang.ClassNotFoundException: my.app.package.a.ae
at java.lang.Class.classForName(Native Method)
at java.lang.Class.forName(Class.java:235)
at java.io.ObjectInputStream.resolveClass(ObjectInputStream.java:2590)
at java.io.ObjectInputStream.readNewClassDesc(ObjectInputStream.java:1846)
at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:826)
at java.io.ObjectInputStream.readNewObject(ObjectInputStream.java:2066)
at java.io.ObjectInputStream.readNonPrimitiveContent(ObjectInputStream.java:929)
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:2285)
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:2240)
at android.os.Parcel.readSerializable(Parcel.java:1945)
... 19 more
Caused by: java.lang.NoClassDefFoundError: my.app.package.a.ae
... 29 more
Caused by: java.lang.ClassNotFoundException: my.app.package.a.ae in loader dalvik.system.PathClassLoader[.]
at dalvik.system.PathClassLoader.findClass(PathClassLoader.java:243)
at java.lang.ClassLoader.loadClass(ClassLoader.java:573)
at java.lang.ClassLoader.loadClass(ClassLoader.java:532)
... 29 more 

请注意，我用的ProGuard - >这就是为什么失踪类的名字是a.ae
。 实际上，a.ae这个名字proguard的给了类MyObject的，这将在下面示出。

Please note that I am using proguard -> that's why the "missing" class name is "a.ae".
Actually, "a.ae" is the name proguard gave to the class "MyObject", which is shown below.

这是为什么发生这种情况的任何IDEIA？

Any ideia on why this happens?

我不认为它必须与ProGuard的，因为如果它造成的ProGuard类重命名一个问题，它应该发生任何时候，我将能够重现这个问题我自己。

I don't think it has to do with proguard, because if it was a problem caused by proguard class renaming, it should happen all times and I would be able to reproduce this issue myself.

是否都与传递序列化对象MyActivity？
在MyActivity我已经

Does it have to do with passing a serializable object to MyActivity?
In MyActivity I have

public void onCreate(Bundle savedInstanceState) {  
     myObj = (MyObject) getIntent().getSerializableExtra("nameOfMyObject");  
//here I am trying to read myObj's properties and app seems to crash here  

}

为MyObject只是用几种类型的类成员，前一个实体：
    公共类为MyObject实现Serializable {

MyObject is just an entity with several types of class members, ex:
public class MyObject implements Serializable {

    /** Generated serialVersionUID */
    static final long serialVersionUID = -267025879233327409L;

    static final String CONSTANT1 = "xpto";

    LinkedHashMap<String, Object> components;

    ArrayList<String> prop1;

    (...)
}

我开始MyActivity有：

I am starting MyActivity with:

MyObject obj = new MyObj(stuff);
Intent intent;
intent = new Intent(CurrentActivity.this, MyActivity.class);
intent.putExtra("nameOfMyObject",  obj);
CurrentActivity.this.startActivity(intent);

你觉得它做的目的是传递（作为一个额外的序列化）的方法是什么？
在我没有找到任何其他解决方案，我想我会序列化的对象自己String，然后通过额外的字符串的情况下。 你怎么看这件事？

Do you think it has to do with the way the object is being passed (as a serializable extra)?
In the case that I don't find any other solution I think I will "serialize" the object myself to a String and then pass the String extra. What do you think about this?

编辑：我试图重现此问题，没有成功，在模拟器和以下设备：

I have tried to reproduce this issue, without success, in the emulator and in the following devices:

-motorola里程碑2的Andr​​oid 2.2
-Samsung的Galaxy Tab的Andr​​oid 2.2
-Vodafone 845的Andr​​oid 2.1
-HTC刺青的Andr​​oid 1.6
-Xperia X10的Andr​​oid 1.6
-Nexus一个Android 2.2的
- 谷歌G1的Andr​​oid 1.5

-Motorola Milestone 2 Android 2.2
-Samsung Galaxy Tab Android 2.2
-Vodafone 845 Android 2.1
-HTC Tatoo Android 1.6
-Xperia X10 Android 1.6
-Nexus One Android 2.2
-Google G1 Android 1.5

什么新的想法？

推荐答案

终于就这一问题得出结论：它被引起的Proguard的，或者更具体地说，是因为我没有一个propper Proguard的配置。

Finally reached a conclusion on this issue: it was being caused by Proguard, or more specifically, because I didn't have a propper Proguard configuration.

原来Proguard的是改变我的序列化的类名，这让的Class.forName（类名）失败。

It turns out Proguard was changing my Serializable's classes names, which makes Class.forName(className) fail.

我不得不重新配置我的 proguard.cfg 文件中添加以下行：

I had to reconfigure my proguard.cfg file adding the following lines:

-keep class * implements java.io.Serializable

-keepclassmembers class * implements java.io.Serializable {
    static final long serialVersionUID;
    private static final java.io.ObjectStreamField[] serialPersistentFields;
    !static !transient <fields>;
    !private <fields>;
    !private <methods>;
    private void writeObject(java.io.ObjectOutputStream);
    private void readObject(java.io.ObjectInputStream);
    java.lang.Object writeReplace();
    java.lang.Object readResolve();
}

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