code: /**
  Copyright (c) 2007-2013 Alysson Bessani, Eduardo Alchieri, Paulo Sousa, and the authors indicated in the @author tags
  
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
  
  http://www.apache.org/licenses/LICENSE-2.0
  
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
  */
  package bftsmart.reconfiguration.util;
  import java.io.BufferedReader;
  import java.io.FileReader;
  import java.net.InetSocketAddress;
  import java.util.Hashtable;
  import java.util.Iterator;
  import java.util.Set;
  import java.util.StringTokenizer;
  
  public class HostsConfig {
      private final static org.apache.log4j.Logger logger = org.apache.log4j.Logger.getLogger(HostsConfig.class);
  
      private Hashtable servers = new Hashtable();
      
      
      /** Creates a new instance of ServersConfig */
      public HostsConfig(String configHome, String fileName) {
          loadConfig(configHome, fileName);
      }
      
      private void loadConfig(String configHome, String fileName){
          try{
              String path =  "";
              String sep = System.getProperty("file.separator");
              if(configHome.equals("")){
                     if (fileName.equals(""))
                          path = "config"+sep+"hosts.config";
                     else
                          path = "config"+sep+fileName;
              }else{
                     if (fileName.equals(""))
                          path = configHome+sep+"hosts.config";
                     else
                         path = configHome+sep+fileName;
              }
              FileReader fr = new FileReader(path);
              BufferedReader rd = new BufferedReader(fr);
              String line = null;
              while((line = rd.readLine()) != null){
                  if(!line.startsWith("#")){
                      StringTokenizer str = new StringTokenizer(line," ");
                      if(str.countTokens() > 2){
                          int id = Integer.valueOf(str.nextToken());
                          String host = str.nextToken();
                          int port = Integer.valueOf(str.nextToken());
                          this.servers.put(id, new Config(id,host,port));
                      }
                  }
              }
              fr.close();
              rd.close();
          }catch(Exception e){
  //            e.printStackTrace(System.out);
              logger.error(e);
          }
      }
      
      public void add(int id, String host, int port){
          if(this.servers.get(id) == null){
              this.servers.put(id, new Config(id,host,port));
          }
      }
      
      public int getNum(){
          return servers.size();
      }
      
      public InetSocketAddress getRemoteAddress(int id){
          Config c = (Config) this.servers.get(id);
          if(c != null){
              return new InetSocketAddress(c.host,c.port);
          }
          return null;
      }
      
      
      public InetSocketAddress getServerToServerRemoteAddress(int id){
          Config c = (Config) this.servers.get(id);
          if(c != null){
              return new InetSocketAddress(c.host,c.port+1);
          }
          return null;
      }
      
      
      public int getPort(int id){
          Config c = (Config) this.servers.get(id);
          if(c != null){
              return c.port;
          }
          return -1;
      }
  
       public int getServerToServerPort(int id){
          Config c = (Config) this.servers.get(id);
          if(c != null){
              return c.port+1;
          }
          return -1;
      }
  
      
      
      public int[] getHostsIds(){
           Set s = this.servers.keySet();
           int[] ret = new int[s.size()];
           Iterator it = s.iterator();
           int p = 0;
           while(it.hasNext()){
              ret[p] = Integer.parseInt(it.next().toString());
              p++;
           }
           return ret;
      }
      
      
      public void setPort(int id, int port){
          Config c = (Config) this.servers.get(id);
          if(c != null){
              c.port = port;
          }
      }
      
      public String getHost(int id){
          Config c = (Config) this.servers.get(id);
          if(c != null){
              return c.host;
          }
          return null;
      }
      
      
      public InetSocketAddress getLocalAddress(int id){
          Config c = (Config) this.servers.get(id);
          if(c != null){
              return new InetSocketAddress(c.port);
          }
          return null;
      }
      
      public class Config{
          public int id;
          public String host;
          public int port;
          
          public Config(int id, String host, int port){
              this.id = id;
              this.host = host;
              this.port = port;
          }
      }
  }
  