RMI JavaFX 2 - NotSerializableException 错误

Question

I'm trying to send objects using Java RMI in a JavaFX 2 project, but when the following code runs it returns a NotSerializableException.

My Admin class is Serializable and so is the super class. However it seems the exception is pointing towards the JavaFX SimpleIntegerProperty fields inside the Admin class.

I don't know what to do from here as the class being sent via RMI is serializable. Any help much appreciated.

ObservableList<Admin> data = null;
try
{
    data = FXCollections.observableArrayList(Main.docServer.getAllAdmins());
}
catch (RemoteException e)
{
    e.printStackTrace();
}

The error I receive:

java.rmi.UnmarshalException: error unmarshalling return; nested exception is: 
java.io.WriteAbortedException: writing aborted; java.io.NotSerializableException: javafx.beans.property.SimpleIntegerProperty
at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:191)
at java.rmi.server.RemoteObjectInvocationHandler.invokeRemoteMethod(RemoteObjectInvocationHandler.java:194)
at java.rmi.server.RemoteObjectInvocationHandler.invoke(RemoteObjectInvocationHandler.java:148)
at $Proxy0.getAllAdmins(Unknown Source)
at com.reece.doc.views.ViewAdmin.getContent(ViewAdmin.java:34)
at com.reece.doc.ApplicationWindow.start(ApplicationWindow.java:32)
at com.reece.doc.Main.start(Main.java:57)
at com.sun.javafx.application.LauncherImpl$5.run(LauncherImpl.java:319)
at com.sun.javafx.application.PlatformImpl$5.run(PlatformImpl.java:206)
at com.sun.javafx.application.PlatformImpl$4.run(PlatformImpl.java:173)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:76)
Caused by: java.io.WriteAbortedException: writing aborted; java.io.NotSerializableException: javafx.beans.property.SimpleIntegerProperty
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1351)
at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1964)
at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1888)
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1771)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1347)
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:369)
at java.util.ArrayList.readObject(ArrayList.java:733)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at java.io.ObjectStreamClass.invokeReadObject(ObjectStreamClass.java:1004)
at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1866)
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1771)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1347)
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:369)
at sun.rmi.server.UnicastRef.unmarshalValue(UnicastRef.java:324)
at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:173)
... 10 more
Caused by: java.io.NotSerializableException: javafx.beans.property.SimpleIntegerProperty
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1180)
at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1528)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1493)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1416)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:346)
at java.util.ArrayList.writeObject(ArrayList.java:710)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:975)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1480)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1416)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:346)
at sun.rmi.server.UnicastRef.marshalValue(UnicastRef.java:292)
at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:332)
at sun.rmi.transport.Transport$1.run(Transport.java:177)
at sun.rmi.transport.Transport$1.run(Transport.java:174)
at java.security.AccessController.doPrivileged(Native Method)
at sun.rmi.transport.Transport.serviceCall(Transport.java:173)
at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:553)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:808)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:667)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
at java.lang.Thread.run(Thread.java:722)

Answer 1

the class being sent via RMI is serializable

It's only serializable if it extends Serializable or Externalizable and all of its non-static non-transient member variables do so as well, and so on recursively until closure. In this case you clearly have one of type javafx.beans.property.SimpleIntegerProperty , which as the exception tells you isn't serializable:

java.io.NotSerializableException: javafx.beans.property.SimpleIntegerProperty

So any class that refers to it, directly or indirectly, isn't serializable either.

Answer 2

You may mark a member variable not to be serialized. And add to class new int field.

private int variableInt = 0;

private transient IntegerProperty variable;

public IntegerProperty variableProperty()
{
    if(variable == null)
    {
        variable = new SimpleIntegerProperty();
        variable.set(variableInt);
    }
    return variable;
}

public void setVariable(int variable)
{
    if(this.variable != null)
        this.variable.set(variable);
    variableInt = variable;
}

public int getVariable()
{
    if(variable == null)
        return variableInt;
    else
        return variable.get();
}