Android Parcelable订单
Android Parcelable订单
提问于 2016-02-24 10:30:28
我在一个android应用程序中使用的一些Parcelable自定义类遇到了问题，我设法以一种非常奇怪的方式解决了这个问题。
当我只在几个特定的情况下阅读一个可打包的文件时，我发生了一次崩溃(这使我认为我的实现并不是完全错误的)。
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.worldcraze.worldcraze/com.worldcraze.worldcraze.AdActivity}: android.os.BadParcelableException: ClassNotFoundException when unmarshalling: Surface Book
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2416)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
at android.app.ActivityThread.-wrap11(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Caused by: android.os.BadParcelableException: ClassNotFoundException when unmarshalling: Surface Book
at android.os.Parcel.readParcelableCreator(Parcel.java:2432)
at android.os.Parcel.readParcelable(Parcel.java:2358)
at com.worldcraze.worldcraze.API.Model.TransportOffer.<init> (TransportOffer.java:33)
at com.worldcraze.worldcraze.API.Model.TransportOffer$1.createFromParcel(TransportO ffer.java:43)
at com.worldcraze.worldcraze.API.Model.TransportOffer$1.createFromParcel(TransportO ffer.java:40)
at android.os.Parcel.createTypedArray(Parcel.java:2167)
at com.worldcraze.worldcraze.API.Model.Ad.<init>(Ad.java:42)
at com.worldcraze.worldcraze.API.Model.Ad$1.createFromParcel(Ad.java:52)
at com.worldcraze.worldcraze.API.Model.Ad$1.createFromParcel(Ad.java:49)
at android.os.Parcel.readParcelable(Parcel.java:2367)
at android.os.Parcel.readValue(Parcel.java:2264)
at android.os.Parcel.readArrayMapInternal(Parcel.java:2614)
at android.os.BaseBundle.unparcel(BaseBundle.java:221)
at android.os.Bundle.getParcelable(Bundle.java:786)
at android.content.Intent.getParcelableExtra(Intent.java:5377)
at com.worldcraze.worldcraze.AdActivity.onCreate(AdActivity.java:57)
at android.app.Activity.performCreate(Activity.java:6251)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369)
... 9 more以下是我最初实现的崩溃发生的模型(Ad.java)
public class Ad implements Parcelable {
public String author;
public String transporter;
public Image cover_urls;
public String details;
public String id;
public int item_size;
public String object_name;
public Money tips;
public Money price;
public Location where_to_buy;
public String resource_uri;
public Location where_to_deliver;
public Permissions permissions;
public TransportOffer[] transport_offers;
public float fees_lemonway_CB;
public String validation_code;
public Date creation_dtime;
public String accepted_transport_offer_id;
protected Ad(Parcel in) {
author = in.readString();
transporter = in.readString();
details = in.readString();
id = in.readString();
item_size = in.readInt();
object_name = in.readString();
resource_uri = in.readString();
cover_urls = in.readParcelable(Image.class.getClassLoader());
tips = in.readParcelable(Money.class.getClassLoader());
price = in.readParcelable(Money.class.getClassLoader());
permissions = in.readParcelable(Permissions.class.getClassLoader());
transport_offers = in.createTypedArray(TransportOffer.CREATOR);
where_to_buy = in.readParcelable(Location.class.getClassLoader());
where_to_deliver = in.readParcelable(Location.class.getClassLoader());
fees_lemonway_CB = in.readFloat();
validation_code = in.readString();
creation_dtime = (Date) in.readSerializable();
accepted_transport_offer_id = in.readString();
}
public static final Creator<Ad> CREATOR = new Creator<Ad>() {
@Override
public Ad createFromParcel(Parcel in) {
return new Ad(in);
}
@Override
public Ad[] newArray(int size) {
return new Ad[size];
}
};
@Override
public int describeContents() {
return 0;
}
@Override
public void writeToParcel(Parcel dest, int flags) {
dest.writeString(author);
dest.writeString(transporter);
dest.writeString(details);
dest.writeString(id);
dest.writeInt(item_size);
dest.writeString(object_name);
dest.writeString(resource_uri);
dest.writeParcelable(cover_urls, flags);
dest.writeParcelable(tips, flags);
dest.writeParcelable(price, flags);
dest.writeParcelable(permissions, flags);
dest.writeTypedArray(transport_offers, flags);
dest.writeParcelable(where_to_buy, flags);
dest.writeParcelable(where_to_deliver, flags);
dest.writeFloat(fees_lemonway_CB);
dest.writeString(validation_code);
dest.writeSerializable(creation_dtime);
dest.writeString(accepted_transport_offer_id);
}}
通过更改某些Parcelable属性的读/写顺序，我设法解决了这个问题。我现在正在读/写where_to_buy和where_to_deliver，就在cover_urls之前，它似乎解决了这个问题。
where_to_buy = in.readParcelable(Location.class.getClassLoader());
where_to_deliver = in.readParcelable(Location.class.getClassLoader());
cover_urls = in.readParcelable(Image.class.getClassLoader());
tips = in.readParcelable(Money.class.getClassLoader());
price = in.readParcelable(Money.class.getClassLoader());
permissions = in.readParcelable(Permissions.class.getClassLoader());
transport_offers = in.createTypedArray(TransportOffer.CREATOR);(在writeToParcel中的顺序是相同的，我只是在这里节省了几行，因为没有粘贴它)。
这个奇怪的修复方法很有魅力，我不知道为什么。
有没有人遇到过类似的情况，或者知道为什么包装/拆包的顺序会影响结果？
干杯！
回答 1
Stack Overflow用户
回答已采纳
发布于 2017-05-05 11:03:56
这不是不正常的行为。如果您了解它是如何内部工作的，您就会理解为什么会有异常。
序列化基本上是按顺序写入字节。因此，您正在按一定的顺序(例如，4-16-1-2)写入一些可变的字节长度，然后从Parcel读取字节。
当从Parcel读取时，您尝试读取例如16个字节，但实际上已经编写了4个字节，这就是崩溃发生的原因。
读取的顺序应该与写入的顺序相匹配，否则，当您尝试读取16个字节时，您最终会遇到这样的情况，但实际上，您的变量是4个字节。
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/35599561
复制相关文章
相似问题
腾讯云开发者
