jade.content.onto.SerializableOntology.java Source code

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Here is the source code for jade.content.onto.SerializableOntology.java

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/**
 * ***************************************************************
 * JADE - Java Agent DEvelopment Framework is a framework to develop
 * multi-agent systems in compliance with the FIPA specifications.
 * Copyright (C) 2000 CSELT S.p.A.
 * 
 * GNU Lesser General Public License
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation,
 * version 2.1 of the License.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA  02111-1307, USA.
 * **************************************************************
 */
package jade.content.onto;
//#MIDP_EXCLUDE_FILE

import jade.content.abs.AbsObject;
import jade.content.abs.AbsPrimitive;
import jade.content.abs.AbsConcept;
import jade.content.schema.PrimitiveSchema;
import jade.content.schema.ConceptSchema;

import org.apache.commons.codec.binary.Base64;
import java.io.*;

/**
 This ontology allows dealing with Java Serializable objects as
 if they were instances of ontological elements.
 <br>
 <b>NOT available in MIDP</b>
 <br>
 @author Giovanni Caire - TILAB
 */
public class SerializableOntology extends Ontology {
    // The singleton instance of this ontology
    private static final SerializableOntology theInstance = new SerializableOntology();

    public static final String SERIALIZABLE = "serializable";
    public static final String SERIALIZABLE_VALUE = "value";

    private ClassLoader myClassLoader;

    /**
     * Returns the singleton instance of the <code>SerializableOntology</code>.
     * @return the singleton instance of the <code>SerializableOntology</code>
     */
    public static Ontology getInstance() {
        return theInstance;
    }

    /**
     Construct a SerializableOntology object
     */
    private SerializableOntology() {
        super("Serializable-ontology", (Ontology) null, null);
        try {
            // Add the primitive schema for binary data
            PrimitiveSchema stringSchema = (PrimitiveSchema) BasicOntology.getInstance()
                    .getSchema(BasicOntology.STRING);
            add(stringSchema);
            // Add the schema for a generic Serializable object
            ConceptSchema serializableSchema = new ConceptSchema(SERIALIZABLE);
            serializableSchema.add(SERIALIZABLE_VALUE, stringSchema);
            add(serializableSchema);
        } catch (Exception e) {
            // Should never happen
            e.printStackTrace();
        }
    }

    public void setClassLoader(ClassLoader cl) {
        myClassLoader = cl;
    }

    //#APIDOC_EXCLUDE_BEGIN
    /**
     */
    protected Object toObject(AbsObject abs, String lcType, Ontology globalOnto)
            throws UnknownSchemaException, UngroundedException, OntologyException {
        if (SERIALIZABLE.equals(abs.getTypeName())) {
            try {
                AbsPrimitive absValue = (AbsPrimitive) abs.getAbsObject(SERIALIZABLE_VALUE);
                String stringValue = absValue.getString();
                byte[] value = Base64.decodeBase64(stringValue.getBytes("US-ASCII"));
                ObjectInput in = new ObjectInputStream(new ByteArrayInputStream(value)) {
                    protected Class resolveClass(ObjectStreamClass v) throws IOException, ClassNotFoundException {
                        if (myClassLoader != null) {
                            // FIXME: Manage primitive class fields. Refactor with AgentMobilityService
                            return Class.forName(v.getName(), true, myClassLoader);
                        } else {
                            return super.resolveClass(v);
                        }
                    }
                };
                return in.readObject();
            } catch (Throwable t) {
                throw new OntologyException("Error in object deserialization.", t);
            }
        } else {
            throw new OntologyException("Abs-object " + abs + " is not serializable");
        }
    }

    /**
     */
    protected AbsObject fromObject(Object obj, Ontology globalOnto)
            throws UnknownSchemaException, OntologyException {
        // If obj is already an abstract descriptor --> just return it
        if (obj instanceof AbsObject) {
            return (AbsObject) obj;
        }

        if (obj instanceof Serializable) {
            try {
                ByteArrayOutputStream baos = new ByteArrayOutputStream();
                ObjectOutputStream out = new ObjectOutputStream(baos);
                out.writeObject(obj);
                AbsConcept absSerializable = new AbsConcept(SERIALIZABLE);
                String stringValue = new String(Base64.encodeBase64(baos.toByteArray()), "US-ASCII");
                absSerializable.set(SERIALIZABLE_VALUE, stringValue);
                return absSerializable;
            } catch (Throwable t) {
                throw new OntologyException("Error in object serialization.", t);
            }
        } else {
            throw new OntologyException("Object " + obj + " is not serializable");
        }
    }
    //#APIDOC_EXCLUDE_END

    //#J2ME_EXCLUDE_BEGIN
    private Object writeReplace() throws ObjectStreamException {
        return new DummySerializableOntology();
    }

    private static class DummySerializableOntology implements Serializable {

        private Object readResolve() throws ObjectStreamException {
            return SerializableOntology.getInstance();
        }
    }
    //#J2ME_EXCLUDE_END
}