Association.java

/*******************************************************************************
 * Copyright (c) 1998, 2015 Oracle and/or its affiliates. All rights reserved.
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
 * which accompanies this distribution.
 * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * Contributors:
 *     Oracle - initial API and implementation from Oracle TopLink
******************************************************************************/
package org.eclipse.persistence.tools.workbench.utility;

/**
 * Straightforward definition of an object pairing.
 * The key is immutable.
 */
public interface Association {

    /**
     * Return the association's key.
     */
    Object getKey();

    /**
     * Return the association's value.
     */
    Object getValue();

    /**
     * Set the association's value.
     * Return the previous value.
     */
    Object setValue(Object value);

    /**
     * Return true if both the associations' keys and values
     * are equal.
     */
    boolean equals(Object o);

    /**
     * Return a hash code based on the association's
     * key and value.
     */
    int hashCode();

}