source: src/main/java/genius/core/repository/ParticipantRepItem.java

package genius.core.repository;

import java.util.ArrayList;
import java.util.List;

import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlElementWrapper;
import javax.xml.bind.annotation.XmlSeeAlso;
import javax.xml.bind.annotation.XmlType;

import genius.core.exceptions.InstantiateException;
import genius.core.parties.NegotiationParty;
import genius.core.repository.boa.BoaPartyRepItem;

/**
 * Abstract superclass for RepItems that can generate Participants.
 *
 */
@SuppressWarnings("serial")
@XmlSeeAlso({ BoaPartyRepItem.class, PartyRepItem.class })
@XmlType
public abstract class ParticipantRepItem implements RepItem {

        /**
         * true iff the cached elemenents have been initialized. Only
         * the @XmlElement objects are set hard, the others are set when needed.
         */
        private boolean initialized = false;

        /**
         * Unused but still in some XML files. Maybe needed in future?
         */
        @XmlElementWrapper(name = "properties")
        @XmlElement(name = "property")
        private List<String> properties = new ArrayList<String>();

        /**
         * The protocol that this item supports. file path including the class name.
         * cached.
         */
        private String protocolClassPath = null;

        // deserialization support
        protected ParticipantRepItem() {
        }

        /**
         * @return the actual {@link NegotiationParty} that this refers to.
         * @throws InstantiateException
         *             if party can't be loaded
         * 
         */
        public abstract NegotiationParty load() throws InstantiateException;

        public Boolean isMediator() {
                return false;
        }

        @Override
        public int hashCode() {
                return 0;
        }

        /**
         * 
         * @return a unique name that identifies this participant. Used e.g. to
         *         create a storage space. Can be derived from the class name or
         *         other settings in the participant. Notice that {@link #getName()}
         *         may not be unique.
         */
        public abstract String getUniqueName();

        public String getProtocolClassPath() {
                try {
                        initSilent();
                } catch (InstantiateException e) {
                        return e.toString();
                }
                return protocolClassPath;
        }

        /**
         * Init our fields to cache the party information. party must have been set
         * before getting here.
         * 
         * @param party
         * @throws InstantiateException
         */
        protected NegotiationParty init() throws InstantiateException {
                NegotiationParty party1 = load();
                protocolClassPath = party1.getProtocol().getCanonicalName();
                initialized = true;
                return party1;
        }

        /**
         * call init but suppress any exceptions and print just a stacktrace.
         * 
         * @throws InstantiateException
         */
        final protected void initSilent() throws InstantiateException {
                if (initialized)
                        return;
                init();
        }

        /**
         * @return a descriptor that is unique for this rep item class. Typically a
         *         full.class.path but may be a composite.
         */
        abstract public String getClassDescriptor();
}