为什么我不能在 Java 中使用 ObjectOutputStream 发送可序列化对象？

Question

我想在Java中发送一个带有ObjectOutputStream的对象。我有一个名为TicketList的类。

这是我的班级：

public class TicketList implements Serializable{
    private ArrayList<Ticket> ticketlist; 

    //Konstruktor: Erstellt eine Liste mit einerm Benutzername
    public TicketList(ArrayList<Ticket> list){
        this.ticketlist = list;
    }
    //Standart Konstruktor
    public TicketList(){
        ticketlist = new ArrayList<>();
    }
    //Fügt der Liste ein neues Element hinzu
    public void addToTicketList(Ticket ticket){
        ticketlist.add(ticket);
    }
    //Gibt die Liste zurück
    public List<Ticket> getTicketList(){
        //Daten werden aus der Datenbank geladen
        return ticketlist; 
    }
    public Ticket getTicketByIndex(int index){
        return ticketlist.get(index);
    }
}

我收到此错误：

java.io.NotSerializableException: taraticketmodel.Ticket
    at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1184)
    at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
    at java.util.ArrayList.writeObject(ArrayList.java:762)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:988)
    at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
    at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
    at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
    at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
    at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
    at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
    at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
    at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
    at taraticketmodel.ClientManager.sendObjectToServer(ClientManager.java:28)
    at taraticketclient.Service.send(Service.java:23)
    at taraticketfrontendtest.MainTest.main(MainTest.java:45)

如果我用其他类测试它，它可以:(

Answer 1

应该实现可序列化的类是存储在 ArrayList 中的类，而不是用于构建 ArrayList 的类。