Code example: Compare strings as per rules specified by given locale

The following code example shows how to use the Mobile Internationalization API to compare and sort strings as per rules specified by given locale.

/*
 *
 * Copyright (c) 2007, Sun Microsystems, Inc.
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *  * Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *  * Neither the name of Sun Microsystems nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package example.mia.demo;

import java.util.Random;

import javax.microedition.global.*;
import javax.microedition.lcdui.*;
import javax.microedition.midlet.MIDlet;


/**
 * StrComparatorDemo MIDlet demonstrates locale dependent
 * sorting of strings.
 * Slovak cities are sorted using default comparator or comparator
 * initialized with slovak locale.
 *
 * @version
 */
public final class StrComparatorDemo extends MIDlet implements CommandListener {
    private static final Random random = new Random();
    private final Command exitCommand;
    private final Command shuffleCommand;
    private final Command sortDefCommand;
    private final Command sortSkyCommand;
    private final Form mainForm;
    private StringComparator defComparator;
    private StringComparator skyComparator;
    private String[] cities =
        new String[] {
            "Horovce", "Chorv\u00e1tsky Grob", "Z\u00e1kamenn\u00e9", "\u0160trba", "Zalaba",
            "Str\u00e1\u017eske", "Chorv\u00e1ty", "Hoste", "Stre\u010dno", "\u017dakovce",
            "Z\u00e1kop\u010die", "\u017dakarovce"
        };

    public StrComparatorDemo() {
        mainForm = new Form("String Comparator");

        updateStrings();

        try {
            defComparator = new StringComparator(null, StringComparator.IDENTICAL);
            skyComparator = new StringComparator("sk", StringComparator.IDENTICAL);
        } catch (UnsupportedLocaleException e) {
        }

        exitCommand = new Command("Exit", Command.EXIT, 1);
        shuffleCommand = new Command("Shuffle", Command.SCREEN, 1);
        sortDefCommand = new Command("Sort - default", Command.SCREEN, 2);
        sortSkyCommand = new Command("Sort - slovak", Command.SCREEN, 2);

        mainForm.addCommand(exitCommand);
        mainForm.addCommand(shuffleCommand);
        mainForm.addCommand(sortDefCommand);
        mainForm.addCommand(sortSkyCommand);

        mainForm.setCommandListener(this);
    }

    private void updateStrings() {
        mainForm.deleteAll();

        for (int i = 0; i < cities.length; ++i) {
            mainForm.append(cities[i] + "\n");
        }
    }

    private static void sort(String[] array, StringComparator comparator) {
        boolean changed;
        changed = true;

        for (int j = array.length - 1; (j > 0) && changed; --j) {
            changed = false;

            for (int i = 0; i < j; ++i) {
                if (comparator.compare(array[i], array[i + 1]) > 0) {
                    String tmp = array[i + 1];
                    array[i + 1] = array[i];
                    array[i] = tmp;
                    changed = true;
                }
            }
        }
    }

    private static void shuffle(String[] array2, String[] array, int step) {
        int k = 0;

        for (int i = step - 1; i >= 0; --i) {
            for (int j = i; j < array.length; j += step) {
                array2[k++] = array[j];
            }
        }
    }

    private static void shuffle(String[] array) {
        String[] array2 = new String[array.length];

        for (int i = 0; i < 10; ++i) {
            shuffle(array2, array, random.nextInt(array.length) + 1);

            String[] tmpArray = array;
            array = array2;
            array2 = tmpArray;
        }
    }

    protected void startApp() {
        Display.getDisplay(this).setCurrent(mainForm);
    }

    protected void pauseApp() {
    }

    protected void destroyApp(boolean unconditional) {
    }

    public void commandAction(Command c, Displayable d) {
        if (c == shuffleCommand) {
            shuffle(cities);
            updateStrings();
        } else if (c == sortDefCommand) {
            sort(cities, defComparator);
            updateStrings();
        } else if (c == sortSkyCommand) {
            sort(cities, skyComparator);
            updateStrings();
        } else if (c == exitCommand) {
            destroyApp(false);
            notifyDestroyed();
        }
    }
}