Ensure Serialization of Instance-Level State

The non-static member variables contain the instance-level state.
If they are primitive or serializable then its OK.
Your classes might not be serializable. Also, Java classes such as ArrayList are not serializable!
Your choices are:

Make the variable transient:
```
private transient Object myobject[];
```
so it will not get serialized (be careful!)

Declare which variables should be stored by defining a special variable:

private static final ObjectSreamField[] serialPersistentFields =
    { new ObjectStreamField("size", Integer.Type), ... };

Do your own serialization by implementing

private void writeObject(java.io.ObjectOutputStream out) throws IOException;
private void readOject(java.io.ObjectInputStream in) 
       throws IOException, ClassNotFoundException;

these methods can invoke defaultWriteObject() to invoke default serialization on the non-transient members.