抽象类序列化异常

Question

我正在尝试开发一个小 Android 游戏，但我很难理解如何克服这个问题。

我想做的是在活动之间发送数据。为了实现这一点，我正在使用意图附加功能。 我尝试发送的数据是 ArrayList

Item.java，

public abstract class Item implements Serializable {

    private String fieldA;
    private int fieldB;
      
     *getters and setters*
    
    abstract void use();
}

每个项目的使用方法都不同，这就是为什么我使用抽象

（例如创建项目）

Item hpPotion = new Item() {
            @Override
            public void use() {
                player.setHealth(player.getHealth() + 10)
            }
        };

时收到错误：

Intent intent = new Intent(HistoryActivity.this,BagActivity.class);
                    intent.putExtra("items",player.getItems());
                    someActivityResultLauncher.launch(intent,options);

，然后在启动新的 Activity StackTrace

E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.example.decisions, PID: 22018
    java.lang.RuntimeException: Parcelable encountered IOException writing serializable object (name = com.example.decisions.HistoryActivity$7)
        at android.os.Parcel.writeSerializable(Parcel.java:2116)
        at android.os.Parcel.writeValue(Parcel.java:1886)
        at android.os.Parcel.writeList(Parcel.java:1095)
        at android.os.Parcel.writeValue(Parcel.java:1835)
        at android.os.Parcel.writeArrayMapInternal(Parcel.java:978)
        at android.os.BaseBundle.writeToParcelInner(BaseBundle.java:1629)
        at android.os.Bundle.writeToParcel(Bundle.java:1303)
        at android.os.Parcel.writeBundle(Parcel.java:1047)
        at android.content.Intent.writeToParcel(Intent.java:10871)
        at android.app.IActivityTaskManager$Stub$Proxy.startActivity(IActivityTaskManager.java:3887)
        at android.app.Instrumentation.execStartActivity(Instrumentation.java:1727)
        at android.app.Activity.startActivityForResult(Activity.java:5405)
        at androidx.activity.ComponentActivity.startActivityForResult(ComponentActivity.java:574)
        at androidx.core.app.ActivityCompat.startActivityForResult(ActivityCompat.java:237)
        at androidx.activity.ComponentActivity$2.onLaunch(ComponentActivity.java:208)
        at androidx.activity.result.ActivityResultRegistry$2.launch(ActivityResultRegistry.java:166)
        at com.example.decisions.HistoryActivity$2.onClick(HistoryActivity.java:96)
        at android.view.View.performClick(View.java:7559)
        at android.view.View.performClickInternal(View.java:7536)
        at android.view.View.access$3600(View.java:828)
        at android.view.View$PerformClick.run(View.java:28700)
        at android.os.Handler.handleCallback(Handler.java:938)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:236)
        at android.app.ActivityThread.main(ActivityThread.java:7861)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:600)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:967)
     Caused by: java.io.NotSerializableException: com.example.decisions.HistoryActivity
        at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1240)
        at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1604)
        at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1565)
        at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1488)
        at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1234)
        at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:354)
        at android.os.Parcel.writeSerializable(Parcel.java:2111)
        at android.os.Parcel.writeValue(Parcel.java:1886) 
        at android.os.Parcel.writeList(Parcel.java:1095) 
        at android.os.Parcel.writeValue(Parcel.java:1835) 
        at android.os.Parcel.writeArrayMapInternal(Parcel.java:978) 
        at android.os.BaseBundle.writeToParcelInner(BaseBundle.java:1629) 
        at android.os.Bundle.writeToParcel(Bundle.java:1303) 
        at android.os.Parcel.writeBundle(Parcel.java:1047) 
        at android.content.Intent.writeToParcel(Intent.java:10871) 
        at android.app.IActivityTaskManager$Stub$Proxy.startActivity(IActivityTaskManager.java:3887) 
        at android.app.Instrumentation.execStartActivity(Instrumentation.java:1727) 
        at android.app.Activity.startActivityForResult(Activity.java:5405) 
        at androidx.activity.ComponentActivity.startActivityForResult(ComponentActivity.java:574) 
        at androidx.core.app.ActivityCompat.startActivityForResult(ActivityCompat.java:237) 
        at androidx.activity.ComponentActivity$2.onLaunch(ComponentActivity.java:208) 
        at androidx.activity.result.ActivityResultRegistry$2.launch(ActivityResultRegistry.java:166) 
        at com.example.decisions.HistoryActivity$2.onClick(HistoryActivity.java:96) 
        at android.view.View.performClick(View.java:7559) 
        at android.view.View.performClickInternal(View.java:7536) 
        at android.view.View.access$3600(View.java:828) 
        at android.view.View$PerformClick.run(View.java:28700) 
        at android.os.Handler.handleCallback(Handler.java:938) 
        at android.os.Handler.dispatchMessage(Handler.java:99) 
        at android.os.Looper.loop(Looper.java:236) 
    ```

What would be the best approach to solve my problem?

Thank you all

Answer 1

您正在尝试直接或间接序列化 Activity（您尝试序列化的内容引用了 Activity）。这是不可能的，因为 Activity 没有实现 Serialized。要正确实现 Serialized，所有成员变量都必须是原语或本身实现 Serialized。

编辑：如果 Item 是 Activity 的子类，它可能会获取隐式父引用。在这种情况下，请将其设为静态类。