"Designing for Object Serialization"
Vol. 6, Issue 7, p. 64

	


Listing 1

java.io.NotSerializableException: bw.dm.impl.FieldAspectAdapter
        at java.io.ObjectOutputStream.outputObject(ObjectOutputStream.java:845)
        at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:342)
        at java.io.ObjectOutputStream.outputArray(ObjectOutputStream.java:811)
        at java.io.ObjectOutputStream.checkSubstitutableSpecialClasses(...:432)
        at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:337)
        at java.io.ObjectOutputStream.outputClassFields(ObjectOutputStream.java:1567)
        at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:453)
        at java.io.ObjectOutputStream.outputObject(ObjectOutputStream.java:911)
        at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:342)
        . . .



Listing 2

package bw.dm.test;


import java.io.*;


/**
 * Serializes and deserializes an object. Used to verify
 * that the object can be successfully serialized (and
 * deserialized).
 *
 * Simulates the typical serialization process of
 * serializing an object, persisting the data somewhere
 * (pehaps in a file), retreiving the persistent data,
 * and deserializing it to get the object back.
 *
 * DataMapper examples do not <EM>have</EM> to use
 * serialization unless they need it. But format maps
 * are expected to be serializible, and this is a good
 * way to test one to make sure that it is.
 *
 * @see java.io.Serializable
 * @see java.io.ObjectInput
 * @see java.io.ObjectOutput
 */
public class ObjectSerializer {


        public static Object serializeAndDeserialize(Serializable obj) {
                try {
                        byte[] bytes = ObjectSerializer.serialize(obj);
                        return ObjectSerializer.deserialize(bytes);
                }
                catch (IOException ex) {
                        throw new RuntimeException("Serialization failed: " 
			+ ex.getClass().getName() + " - " + ex.getMessage());
                }
                catch (ClassNotFoundException ex) {
                        throw new RuntimeException("Serialization failed: " 
			+ ex.getClass().getName() + " - " + ex.getMessage());
                }
        }


        protected static byte[] serialize(Serializable obj)
        throws IOException {
                ByteArrayOutputStream stream = new ByteArrayOutputStream();
                ObjectOutput serialStream = new ObjectOutputStream(stream);
                serialStream.writeObject(obj);
                return stream.toByteArray();
        }


        protected static Object deserialize(byte[] bytes)
        throws IOException, ClassNotFoundException {
        InputStream stream = new ByteArrayInputStream(bytes);
                ObjectInput serialStream = new ObjectInputStream(stream);
                return serialStream.readObject();
        }
}



Listing 3

public class FieldAspectAdapterProxy extends FieldAdapterProxy {
        protected AspectSpec spec;
        transient protected ProtocolAdapter adapter = null;
        protected void setupDomainAdapter() {
                if (adapter == null) {
                        try {
                                this.initializeAdapter();
                        }
                        catch . . .
                }
        }
        protected void initializeAdapter() throws . . . {
                adapter = new FieldAspectAdapter(field, spec);
        }
        . . .
}
architectures using various J2EE technologies and embeddable tools.