Java.io.NotSerializableException: engine.MyMetaData

Question

the exception....
java.rmi.UnmarshalException: error unmarshalling return; nested exception is:
     java.io.WriteAbortedException: Writing aborted by exception; java.io.NotSerializableException: engine.MyMetaData
java.io.WriteAbortedException: Writing aborted by exception; java.io.NotSerializableException: engine.MyMetaData
     at java.io.ObjectInputStream.readObject(Unknown Source)
     at java.io.ObjectInputStream.inputClassFields(Unknown Source)
     at java.io.ObjectInputStream.defaultReadObject(Unknown Source)
     at java.io.ObjectInputStream.inputObject(Unknown Source)
     at java.io.ObjectInputStream.readObject(Unknown Source)
     at java.io.ObjectInputStream.readObject(Unknown Source)
     at sun.rmi.server.UnicastRef.unmarshalValue(Unknown Source)
     at sun.rmi.server.UnicastRef.invoke(Unknown Source)
     at engine.ComputeEngine1_Stub.executeTask(ComputeEngine1_Stub.java:38)
     at client.ComputeClientVisual.init(ComputeClientVisual.java:410)
     at sun.applet.AppletPanel.run(Unknown Source)
     at java.lang.Thread.run(Unknown Source)
the class..
I send this class via RMI
public class MyTableModel extends AbstractTableModel {
     public String[] columnNames = {};
     public Vector rows = new Vector();
     public MyMetaData metaData;//here is the class
that is my class that returns the exception
public class MyMetaData {
     private Integer [] typeOfColumn;
     private Boolean [] isWritable;
     private Integer numberOfColumns;
     private String tableName[];
I dont know why this exception
does anybody cant help me whit this?
I'll apreciate your help

Answer 1

Don't you see "java.io.NotSerializableException" in the output !!. RMI uses serialization protcol to transfer objects from one address space to another, so all parameters/return values of a remote method must be serializable.
Just make sure all prameters/return values of a remote method implements "Serializable" marker interface. MyMetaData class must implement "Serializable" interface in order to be transported as a return value of a RMI method.
-- Srinath Mandalapu