NotSerializableException發生在它不應該在的地方

Question

我一直在使用Java幾個月，現在我還是比較新，所以任何幫助表示讚賞。我一直在製作一款遊戲（基於另一款遊戲），並且想要製作關卡編輯器。我無法將信息保存到.ser文件，儘管我在其他類中的其他位置沒有任何問題。錯誤是java.io.NotSerializableException: resources.Sample$Ball，但它給我的行號與該類無關。我有一個名爲Sample的類，裏面有一個叫做Ball的私人類，所以我非常理解，但它給我提供信息的事實是沒有意義的。 Sample類從來只在一個類中使用過一次，並不是我遇到錯誤的那個類。我從來沒有遇到過這個類或Ball子類的問題，因爲它們非常僻靜，很少被使用。

兩個行號的錯誤給我的是： at LevelEditor.saveDialog(LevelEditor.java:309) at LevelEditor.actionPerformed(LevelEditor.java:256)

那些行號的代碼行如下： oos.writeObject(new CustomSave(platforms, stars, ball, levelSize));

這是哪裏的問題實際上是存在的，而其他行號就是我稱之爲上述代碼所在的函數的地方。CustomSave類所接受的變量仍然與Sample或Ball類無關。而且因爲CustomSave班是如此之小，我也會在這裏提供。我還會爲上面的行號提供背景信息。

語境代碼

try { 
    File f = new File(filename); 
    f.createNewFile(); 
    FileOutputStream fos = new FileOutputStream(f); 
    ObjectOutputStream oos = new ObjectOutputStream(fos); 
    oos.writeObject(new CustomSave(platforms, stars, ball, levelSize)); 
    oos.close(); 
} catch (Exception e1) { 
    e1.printStackTrace(); 
} 

CustomSave類

package resources; 

import java.awt.Dimension; 
import java.io.*; 
import java.util.ArrayList; 
import resources.BouncyBall; 

public class CustomSave implements Serializable { 
    private ArrayList<DragablePlatform> platforms; 
    private ArrayList<StarPolygon> stars; 

    private StaticBall ball; 
    private Dimension levelSize; 

    public CustomSave(ArrayList<DragablePlatform> platforms, ArrayList<StarPolygon> stars, StaticBall ball, Dimension levelSize){ 
     this.platforms = platforms; this.stars = stars; this.ball = ball; this.levelSize = levelSize; 
    } 

    public ArrayList<DragablePlatform> getPlatforms() { 
     return platforms; 
    } 
    public ArrayList<StarPolygon> getStars() { 
     return stars; 
    } 
    public BouncyBall getBall() { 
     return ball; 
    } 
    public Dimension getLevelSize() { 
     return levelSize; 
    } 
} 

同樣，我不知道爲什麼我得到這個錯誤，因爲它沒有任何意義。爲了嘗試解決問題，我嘗試在Sample類的Ball類中實施Serializable，並且在一定程度上解決了問題。該錯誤停止列出Sample$Ball作爲問題，而是列出另一個隨機類作爲問題，另一類與我試圖做的事完全沒有關係。

完全錯誤

java.io.NotSerializableException: resources.Sample$Ball 
at java.io.ObjectOutputStream.writeObject0(Unknown Source) 
at java.io.ObjectOutputStream.defaultWriteFields(Unknown Source) 
at java.io.ObjectOutputStream.writeSerialData(Unknown Source) 
at java.io.ObjectOutputStream.writeOrdinaryObject(Unknown Source) 
at java.io.ObjectOutputStream.writeObject0(Unknown Source) 
at java.io.ObjectOutputStream.writeArray(Unknown Source) 
at java.io.ObjectOutputStream.writeObject0(Unknown Source) 
at java.io.ObjectOutputStream.access$300(Unknown Source) 
at java.io.ObjectOutputStream$PutFieldImpl.writeFields(Unknown Source) 
at java.io.ObjectOutputStream.writeFields(Unknown Source) 
at java.awt.Container.writeObject(Unknown Source) 
at sun.reflect.GeneratedMethodAccessor11.invoke(Unknown Source) 
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) 
at java.lang.reflect.Method.invoke(Unknown Source) 
at java.io.ObjectStreamClass.invokeWriteObject(Unknown Source) 
at java.io.ObjectOutputStream.writeSerialData(Unknown Source) 
at java.io.ObjectOutputStream.writeOrdinaryObject(Unknown Source) 
at java.io.ObjectOutputStream.writeObject0(Unknown Source) 
at java.io.ObjectOutputStream.defaultWriteFields(Unknown Source) 
at java.io.ObjectOutputStream.writeSerialData(Unknown Source) 
at java.io.ObjectOutputStream.writeOrdinaryObject(Unknown Source) 
at java.io.ObjectOutputStream.writeObject0(Unknown Source) 
at java.io.ObjectOutputStream.defaultWriteFields(Unknown Source) 
at java.io.ObjectOutputStream.writeSerialData(Unknown Source) 
at java.io.ObjectOutputStream.writeOrdinaryObject(Unknown Source) 
at java.io.ObjectOutputStream.writeObject0(Unknown Source) 
at java.io.ObjectOutputStream.defaultWriteFields(Unknown Source) 
at java.io.ObjectOutputStream.writeSerialData(Unknown Source) 
at java.io.ObjectOutputStream.writeOrdinaryObject(Unknown Source) 
at java.io.ObjectOutputStream.writeObject0(Unknown Source) 
at java.io.ObjectOutputStream.writeObject(Unknown Source) 
at LevelEditor.saveDialog(LevelEditor.java:454) 
at LevelEditor.actionPerformed(LevelEditor.java:298) 
at javax.swing.AbstractButton.fireActionPerformed(Unknown Source) 
at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source) 
at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source) 
at javax.swing.DefaultButtonModel.setPressed(Unknown Source) 
at javax.swing.AbstractButton.doClick(Unknown Source) 
at javax.swing.plaf.basic.BasicMenuItemUI.doClick(Unknown Source) 
at javax.swing.plaf.basic.BasicMenuItemUI$Handler.mouseReleased(Unknown Source) 
at java.awt.Component.processMouseEvent(Unknown Source) 
at javax.swing.JComponent.processMouseEvent(Unknown Source) 
at java.awt.Component.processEvent(Unknown Source) 
at java.awt.Container.processEvent(Unknown Source) 
at java.awt.Component.dispatchEventImpl(Unknown Source) 
at java.awt.Container.dispatchEventImpl(Unknown Source) 
at java.awt.Component.dispatchEvent(Unknown Source) 
at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source) 
at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source) 
at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source) 
at java.awt.Container.dispatchEventImpl(Unknown Source) 
at java.awt.Window.dispatchEventImpl(Unknown Source) 
at java.awt.Component.dispatchEvent(Unknown Source) 
at java.awt.EventQueue.dispatchEventImpl(Unknown Source) 
at java.awt.EventQueue.access$500(Unknown Source) 
at java.awt.EventQueue$3.run(Unknown Source) 
at java.awt.EventQueue$3.run(Unknown Source) 
at java.security.AccessController.doPrivileged(Native Method) 
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source) 
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source) 
at java.awt.EventQueue$4.run(Unknown Source) 
at java.awt.EventQueue$4.run(Unknown Source) 
at java.security.AccessController.doPrivileged(Native Method) 
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source) 
at java.awt.EventQueue.dispatchEvent(Unknown Source) 
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source) 
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source) 
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source) 
at java.awt.EventDispatchThread.pumpEvents(Unknown Source) 
at java.awt.EventDispatchThread.pumpEvents(Unknown Source) 
at java.awt.EventDispatchThread.run(Unknown Source) 

關卡編輯器線路454

oos.writeObject(new CustomSave(platforms, stars, ball, levelSize));

關卡編輯器線路298

saveDialog();（包含上述行的功能）

所有幫助非常感謝，如果你需要任何其他的東西只是問。

謝謝。

Answer 1

系列化正常，你必須確保所有你要序列化實現Serializable接口的類，我有同樣的問題，一旦我試圖挽救一個對象在同一時間，看看有什麼物體所造成的問題 - 平齊oos。

try {   
    FileOutputStream fos = new FileOutputStream(new File(filename)); 
    ObjectOutputStream oos = new ObjectOutputStream(fos); 
    oos.writeObject(platforms); 
    oos.writeObject(stars); 
    oos.writeObject(balls); 
    oos.writeObject(levelSize); 
    oos.flush(); 
    oos.close(); 
}catch (Exception e1) { 
    e1.printStackTrace(); 
} 

Answer 2

對於序列化/反序列化是成功的，下面兩個條件必須爲真：

1. 要序列化的類/反序列化必須實現 java.io.Serializable 接口。
2. 該類別中的所有字段必須是原始類型，或者必須實現接口的 java.io.Serializable。

條件1（滿意）：因爲 CustomSave implements Serializable

條件2（？）：不要StaticBall，DragablePlatform和StarPolygon實現Serializable？

private ArrayList<DragablePlatform> platforms; // ArrayList implements Serializable? Yes, DragablePlatform implements Serializable? 
private ArrayList<StarPolygon> stars; // ArrayList implements Serializable? Yes, StartPolygon implements Serializable? 
private StaticBall ball; // StaticBall implements Serializable? 
private Dimension levelSize; // Dimension implements Serializable? Yes