carfield.com.hk

BubbleSort.java

2004-03-24T16:00:00Z

LinearSort.java

2004-03-24T16:00:00Z

Main.java

2004-03-24T16:00:00Z

package examples.strategy.aspectj;

/* -*- Mode: Java; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * This file is part of the design patterns project at UBC
 *
 * The contents of this file are subject to the Mozilla Public License
 * Version 1.1 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * either http://www.mozilla.org/MPL/ or http://aspectj.org/MPL/.
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is ca.ubc.cs.spl.patterns.
 *
 * Contributor(s): 
 */
 
/**
 * Implements the driver for the strategy design pattern example. 
 *
 * Intent: Define a family of algorithms, encapsulate each one, and make
 * them interchangeable. Strategy lets the algorithm vary independently from 
 * clients that use it.
 *
 * Participatng objects are <code>LinearSort</code> and BubbleSort
 * as Strategies, and <code>Sorter</code> as Context.
 *
 * In this example, an array of 10 numbers is to be sorted. Depending on the
 * number of arguments of the call to <code>Main</code>, linear sort or 
 * bubblesort are used as sorting algorithms. The interface for the strategies
 * is defined in <code>SortingStrategy</code>.
 *
 * This is the AspectJ version.
 *
 * @author Jan Hannemann
 * @author Gregor Kiczales
 * @version 1.0, 05/13/02
 * 
 * @see LinearSort
 * @see BubbleSort
 */

public class Main {	

 /**
 * Returns the content of the int array in a string
 * 
 * @param numbers the int array to display
 * @returns a string with all the ints from the array
 */

	private static String show(int[] numbers) {
		String out = "";
		for (int i=0; i<numbers.length; i++) {
			out += (numbers[i] + " ");
		} 
		return out;
	}

 /**
 * Implements the driver for the strategy example. If called with more
 * than zero arguments, bubblesort is used to sort the array of ten
 * numbers; otherwise linear sort. 
 */ 
 
 	public static void main(String[] args) {
		int[] numbers = {3, 2, 6, 8, 1, 5, 6, 4, 7, 0};
				
		LinearSort sort1 = new LinearSort();
		BubbleSort sort2 = new BubbleSort();
		
		Sorter sorter = new Sorter();
		
		
		if (args.length == 0) {
			SortingStrategy.aspectOf().setConcreteStrategy(sorter, sort1);
		} 
		else {
			SortingStrategy.aspectOf().setConcreteStrategy(sorter, sort2);
		}

		System.out.println("\nPreparing sort...");
		System.out.println("original: "+show(numbers)); 
		numbers = sorter.sort(numbers);
		System.out.println("sorted: "+show(numbers)); 		
	} 
}

Sorter.java

2004-03-24T16:00:00Z

SortingStrategy.java

2004-03-24T16:00:00Z

package examples.strategy.aspectj;


/* -*- Mode: Java; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * This file is part of the design patterns project at UBC
 *
 * The contents of this file are subject to the Mozilla Public License
 * Version 1.1 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * either http://www.mozilla.org/MPL/ or http://aspectj.org/MPL/.
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is ca.ubc.cs.spl.patterns.
 *
 * Contributor(s): 
 */

import ca.ubc.cs.spl.pattern.library.StrategyProtocol;
 
/**
 * Implements the the abstract strategy design pattern protocol
 *
 * Intent: Define a family of algorithms, encapsulate each one, and make
 * them interchangeable. Strategy lets the algorithm vary independently from 
 * clients that use it.
 *
 * Participatng objects are <code>LinearSort</code> and BubbleSort
 * as Strategies, and <code>Sorter</code> as Context.
 *
 * In this example, an array of 10 numbers is to be sorted. Depending on the
 * number of arguments of the call to <code>Main</code>, linear sort or 
 * bubblesort are used as sorting algorithms. 
 *
 * This is the AspectJ version.
 *
 * @author Jan Hannemann
 * @author Gregor Kiczales
 * @version 1.0, 05/13/02
 * 
 * @see LinearSort
 * @see BubbleSort
 */


public aspect SortingStrategy extends StrategyProtocol {
 
	
 /**
 * Assignes the Context role to Sorter
 */

	declare parents: Sorter implements Context;

 /**
 * Assignes the Strategy role to LinearSort
 */

	declare parents: LinearSort implements Strategy;

 /**
 * Assignes the Strategy role to BubbleSort
 */

	declare parents: BubbleSort implements Strategy; 
	
	
 /**
 * Invokes the appropriate strategy's sort() method when the
 * Sorter needs to sort.
 */

	int[] around(Sorter s, int[] numbers): call(int[] Sorter.sort(int[])) && target(s) && args(numbers) {
		Strategy strategy = getConcreteStrategy(s);
		if (strategy instanceof BubbleSort)
			((BubbleSort)strategy).sort(numbers);
		else if (strategy instanceof LinearSort)
			((LinearSort) strategy).sort(numbers);
		return numbers;
	}
}

files.lst

2004-03-24T16:00:00Z