org.hibernate.engine.spi.CollectionKey.java Source code

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Here is the source code for org.hibernate.engine.spi.CollectionKey.java

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/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
 * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
 */
package org.hibernate.engine.spi;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;

import org.hibernate.EntityMode;
import org.hibernate.persister.collection.CollectionPersister;
import org.hibernate.pretty.MessageHelper;
import org.hibernate.type.Type;

/**
 * Uniquely identifies a collection instance in a particular session.
 *
 * @author Gavin King
 */
public final class CollectionKey implements Serializable {
    private final String role;
    private final Serializable key;
    private final Type keyType;
    private final SessionFactoryImplementor factory;
    private final int hashCode;

    public CollectionKey(CollectionPersister persister, Serializable key) {
        this(persister.getRole(), key, persister.getKeyType(), persister.getFactory());
    }

    /**
     * The EntityMode parameter is now ignored. Use the other constructor.
     * @deprecated Use {@link #CollectionKey(CollectionPersister, Serializable)}
     */
    @Deprecated
    public CollectionKey(CollectionPersister persister, Serializable key, EntityMode em) {
        this(persister.getRole(), key, persister.getKeyType(), persister.getFactory());
    }

    private CollectionKey(String role, Serializable key, Type keyType, SessionFactoryImplementor factory) {
        this.role = role;
        this.key = key;
        this.keyType = keyType;
        this.factory = factory;
        //cache the hash-code
        this.hashCode = generateHashCode();
    }

    private int generateHashCode() {
        int result = 17;
        result = 37 * result + role.hashCode();
        result = 37 * result + keyType.getHashCode(key, factory);
        return result;
    }

    public String getRole() {
        return role;
    }

    public Serializable getKey() {
        return key;
    }

    @Override
    public String toString() {
        return "CollectionKey"
                + MessageHelper.collectionInfoString(factory.getCollectionPersister(role), key, factory);
    }

    @Override
    public boolean equals(Object other) {
        if (this == other) {
            return true;
        }
        if (other == null || getClass() != other.getClass()) {
            return false;
        }

        final CollectionKey that = (CollectionKey) other;
        return that.role.equals(role) && keyType.isEqual(that.key, key, factory);
    }

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

    /**
     * Custom serialization routine used during serialization of a
     * Session/PersistenceContext for increased performance.
     *
     * @param oos The stream to which we should write the serial data.
     *
     * @throws java.io.IOException
     */
    public void serialize(ObjectOutputStream oos) throws IOException {
        oos.writeObject(role);
        oos.writeObject(key);
        oos.writeObject(keyType);
    }

    /**
     * Custom deserialization routine used during deserialization of a
     * Session/PersistenceContext for increased performance.
     *
     * @param ois The stream from which to read the entry.
     * @param session The session being deserialized.
     *
     * @return The deserialized CollectionKey
     *
     * @throws IOException
     * @throws ClassNotFoundException
     */
    public static CollectionKey deserialize(ObjectInputStream ois, SessionImplementor session)
            throws IOException, ClassNotFoundException {
        return new CollectionKey((String) ois.readObject(), (Serializable) ois.readObject(),
                (Type) ois.readObject(), (session == null ? null : session.getFactory()));
    }
}