HelloJGraphT.java

/* ==========================================
 * JGraphT : a free Java graph-theory library
 * ==========================================
 *
 * Project Info:  http://jgrapht.sourceforge.net/
 * Project Creator:  Barak Naveh (http://sourceforge.net/users/barak_naveh)
 *
 * (C) Copyright 2003-2008, by Barak Naveh and Contributors.
 *
 * This program and the accompanying materials are dual-licensed under
 * either
 *
 * (a) the terms of the GNU Lesser General Public License version 2.1
 * as published by the Free Software Foundation, or (at your option) any
 * later version.
 *
 * or (per the licensee's choosing)
 *
 * (b) the terms of the Eclipse Public License v1.0 as published by
 * the Eclipse Foundation.
 */
/* -----------------
 * HelloJGraphT.java
 * -----------------
 * (C) Copyright 2003-2008, by Barak Naveh and Contributors.
 *
 * Original Author:  Barak Naveh
 * Contributor(s):   -
 *
 * $Id$
 *
 * Changes
 * -------
 * 27-Jul-2003 : Initial revision (BN);
 *
 */
package org.jgrapht.demo;

import java.net.*;

import org.jgrapht.*;
import org.jgrapht.graph.*;


/**
 * A simple introduction to using JGraphT.
 *
 * @author Barak Naveh
 * @since Jul 27, 2003
 */
public final class HelloJGraphT
{
    

    private HelloJGraphT()
    {
    } // ensure non-instantiability.

    

    /**
     * The starting point for the demo.
     *
     * @param args ignored.
     */
    public static void main(String [] args)
    {
        UndirectedGraph<String, DefaultEdge> stringGraph = createStringGraph();

        // note undirected edges are printed as: {<v1>,<v2>}
        System.out.println(stringGraph.toString());

        // create a graph based on URL objects
        DirectedGraph<URL, DefaultEdge> hrefGraph = createHrefGraph();

        // note directed edges are printed as: (<v1>,<v2>)
        System.out.println(hrefGraph.toString());
    }

    /**
     * Creates a toy directed graph based on URL objects that represents link
     * structure.
     *
     * @return a graph based on URL objects.
     */
    private static DirectedGraph<URL, DefaultEdge> createHrefGraph()
    {
        DirectedGraph<URL, DefaultEdge> g =
            new DefaultDirectedGraph<URL, DefaultEdge>(DefaultEdge.class);

        try {
            URL amazon = new URL("http://www.amazon.com");
            URL yahoo = new URL("http://www.yahoo.com");
            URL ebay = new URL("http://www.ebay.com");

            // add the vertices
            g.addVertex(amazon);
            g.addVertex(yahoo);
            g.addVertex(ebay);

            // add edges to create linking structure
            g.addEdge(yahoo, amazon);
            g.addEdge(yahoo, ebay);
        } catch (MalformedURLException e) {
            e.printStackTrace();
        }

        return g;
    }

    /**
     * Craete a toy graph based on String objects.
     *
     * @return a graph based on String objects.
     */
    private static UndirectedGraph<String, DefaultEdge> createStringGraph()
    {
        UndirectedGraph<String, DefaultEdge> g =
            new SimpleGraph<String, DefaultEdge>(DefaultEdge.class);

        String v1 = "v1";
        String v2 = "v2";
        String v3 = "v3";
        String v4 = "v4";

        // add the vertices
        g.addVertex(v1);
        g.addVertex(v2);
        g.addVertex(v3);
        g.addVertex(v4);

        // add edges to create a circuit
        g.addEdge(v1, v2);
        g.addEdge(v2, v3);
        g.addEdge(v3, v4);
        g.addEdge(v4, v1);

        return g;
    }
}

// End HelloJGraphT.java