ContainerDiff.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 org.eclipse.persistence.tools.workbench.utility.ClassTools;
import org.eclipse.persistence.tools.workbench.utility.io.IndentingPrintWriter;


/**
 * This diff records the differences between two unordered collections,
 * noting, in addition to which elements are different, which elements
 * were removed and added.
 */
public class ContainerDiff extends CompositeDiff {
    private final Class javaClass;
    private final Object[] removedElements;
    private final Object[] addedElements;


    public ContainerDiff(Class javaClass, Object object1, Object object2, Diff[] diffs, Object[] removedElements, Object[] addedElements, Differentiator differentiator) {
        super(object1, object2, diffs, differentiator);
        this.javaClass = javaClass;
        this.removedElements = removedElements;
        this.addedElements = addedElements;
    }

    /**
     * @see Diff#different()
     */
    public boolean different() {
        if (this.removedElements.length != 0 ) {
            return true;
        }
        if (this.addedElements.length != 0 ) {
            return true;
        }
        return super.different();
    }

    /**
     * @see Diff#appendDescription(org.eclipse.persistence.tools.workbench.utility.io.IndentingPrintWriter)
     */
    public void appendDescription(IndentingPrintWriter pw) {
        if (this.different()) {
            pw.print("The ");
            pw.print(ClassTools.shortNameFor(this.javaClass));
            pw.print("s are different:");
            pw.println();

            this.appendDiffs(pw);
            this.appendRemovedElements(pw);
            this.appendAddedElements(pw);
        }
    }

    private void appendDiffs(IndentingPrintWriter pw) {
        Diff[] diffs = this.getDiffs();
        boolean headerPrinted = false;
        // preserve the order of the component diffs
        int len = diffs.length;
        for (int i = 0; i < len; i++) {
            Diff diff = diffs[i];
            if (diff.different()) {
                if ( ! headerPrinted) {
                    pw.println("The following pairs of elements have matching \"keys\" but are different:");
                    pw.indent();
                    headerPrinted = true;
                }
                diff.appendDescription(pw);
            }
        }
        if (headerPrinted) {
            pw.undent();
        }
    }

    private void appendRemovedElements(IndentingPrintWriter pw) {
        int len = this.removedElements.length;
        if (len == 0) {
            return;
        }
        pw.println("The following elements were removed (they existed in container 1, but not in container 2):");
        pw.indent();
            for (int i = 0; i < len; i++) {
                pw.println(this.removedElements[i]);
            }
        pw.undent();
    }

    private void appendAddedElements(IndentingPrintWriter pw) {
        int len = this.addedElements.length;
        if (len == 0) {
            return;
        }
        pw.println("The following elements were added (they existed in container 2, but not in container 1):");
        pw.indent();
            for (int i = 0; i < len; i++) {
                pw.println(this.addedElements[i]);
            }
        pw.undent();
    }

    /**
     * return the elements found in container 2 but not container 1
     */
    public Object[] getAddedElements() {
        return this.addedElements;
    }

    /**
     * return the elements found in container 1 but not container 2
     */
    public Object[] getRemovedElements() {
        return this.removedElements;
    }

}