RMI JavaFX 2 - NotSerializableException error

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

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();
}

Answer 2

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.