code: /**
   * Created on 02.11.2004
   *
   * Copyright (c) 2004-2005, Olaf Landsiedel, Protocol Engineering and
   * Distributed Systems, University of Tuebingen
   * 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 the Protocol Engineering and Distributed Systems
   * Group, the name of the University of Tuebingen 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 avrora.sim.radio;
  
  import cck.util.Option;
  import cck.util.Util;
  
  import java.io.*;
  import java.util.*;
  
  /**
   * handles node positions.
   *
   * @author Olaf Landsiedel
   * @author Rodolfo de Paz
   */
  public class TopologyStatic extends Topology {
      public final Option.Str TOPOLOGY_FILE = newOption("topology-file", "",
          "This option can be used to specify the name of " +
          "a file that contains information about the topology of the network.");
  
      /**
       * new topology
       */
      public TopologyStatic() {
          super("Static topology. topology-file must be given!");
      }
      
      /**
       * new topology
       *
       * @param h the help item for the topology as string
       * @param o the options representing the known and unknown options from the command line
       */
      public TopologyStatic(String h) {
          super (h);
      }
      
      public void start() {
          if (TOPOLOGY_FILE.isBlank()) {
              Util.userError("topology-file must be given!");
          }
          parseFile();
      }
  
      protected void parseFile() {
          try {
              String line;
              BufferedReader f = new BufferedReader(new FileReader(TOPOLOGY_FILE.get()));
              while ((line = f.readLine()) != null) {
                  parseLine(line);
              }
              f.close();
          } catch (IOException e) {
              throw Util.unexpected(e);
          }
      }
  
      /**
       * parse one line of the file
       *
       * @param line
       */
      private void parseLine(String line) {
          double[] newpos = new double[4];
          //check for comment
          if (!line.startsWith("#")) {
              StringTokenizer tokenizer = new StringTokenizer(line, " ");
              int count = 0;
              while (tokenizer.hasMoreTokens() && count < 5) {
                  try {
                      if (count == 0)
                          tokenizer.nextToken();
                      else {
                          newpos[count - 1] = Double.parseDouble(tokenizer.nextToken());
                      }
                      count++;
                  } catch (NoSuchElementException e) {
                      throw Util.failure("Error reading topology tokens");
                  }
              }
              if (count == 4) {
                  //found 4 tokens so we won't have obstacles (rho = 0)
                  positions.add(new Position(newpos[0], newpos[1], newpos[2], 0.0));
              }else if (count == 5){
                  //found 5 tokens so density of obstacles is included in topology file
                  positions.add(new Position(newpos[0], newpos[1], newpos[2], newpos[3]));
              }
          }
      }
  
  }
  