MapEntryDifferentiator.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.diff;

import java.util.Map;

import org.eclipse.persistence.tools.workbench.utility.string.StringTools;


/**
 * This differentiator compares two map entries.
 * The two entries are "identical" if their keys and values are
 * both "identical". This applies to both #keyDiff(Object, Object)
 * and #diff(Object, Object).
 */
public class MapEntryDifferentiator implements Differentiator {
    private Differentiator keyDifferentiator;
    private Differentiator valueDifferentiator;


    /**
     * default to "equality" differentiators for both the key and the value
     */
    public MapEntryDifferentiator() {
        this(EqualityDifferentiator.instance(), EqualityDifferentiator.instance());
    }

    public MapEntryDifferentiator(Differentiator keyDifferentiator, Differentiator valueDifferentiator) {
        super();
        this.keyDifferentiator = keyDifferentiator;
        this.valueDifferentiator = valueDifferentiator;
    }

    /**
     * @see Differentiator#diff(Object, Object)
     */
    public Diff diff(Object object1, Object object2) {
        return this.diff(object1, object2, DifferentiatorAdapter.NORMAL);
    }

    /**
     * @see Differentiator#keyDiff(Object, Object)
     */
    public Diff keyDiff(Object object1, Object object2) {
        return this.diff(object1, object2, DifferentiatorAdapter.KEY);
    }

    private Diff diff(Object object1, Object object2, DifferentiatorAdapter adapter) {
        if ((object1 == null) || (object2 == null)) {
            // both arguments should be map entries
            throw new NullPointerException();
        }
        Map.Entry entry1 = (Map.Entry) object1;
        Map.Entry entry2 = (Map.Entry) object2;
        Diff keyDiff = adapter.diff(this.keyDifferentiator, entry1.getKey(), entry2.getKey());
        Diff valueDiff = adapter.diff(this.valueDifferentiator, entry1.getValue(), entry2.getValue());
        return new MapEntryDiff(entry1, entry2, keyDiff, valueDiff, this);
    }

    /**
     * map entries should only belong to a single map
     * @see Differentiator#comparesValueObjects()
     */
    public boolean comparesValueObjects() {
        return false;
    }

    public Differentiator getKeyDifferentiator() {
        return this.keyDifferentiator;
    }
    public void setKeyDifferentiator(Differentiator keyDifferentiator) {
        this.keyDifferentiator = keyDifferentiator;
    }

    public Differentiator getValueDifferentiator() {
        return this.valueDifferentiator;
    }
    public void setValueDifferentiator(Differentiator valueDifferentiator) {
        this.valueDifferentiator = valueDifferentiator;
    }

    /**
     * @see Object#toString()
     */
    public String toString() {
        return StringTools.buildToStringFor(this, this.valueDifferentiator);
    }

}