mobileplacemanager.java

一个agent 工具包,可以开发移动设备应用,考虑了安全措施

package SOMA.mobilePlace;

import SOMA.naming.*;
import SOMA.Environment;
import SOMA.agent.AgentWorker;

import java.util.*;
import java.io.*;

/** Gestore dei place mobili di un dominio.
*
* @author Livio Profiri
*/
public class MobilePlaceManager implements Serializable
{
  transient Environment env;
  Hashtable mobilePlacePositions = new Hashtable();
  Hashtable waitingAgents = new Hashtable();

  public final static PlaceID DISCONNECTED = new PlaceID( "", "" )
    {
      public String toString()
      {
        return "DISCONNECTED";
      }

      public boolean equals(Object obj)
      {
        return this == obj;
      }
    };

  /** Costruttore.
  * @param env L'environment del place.
  */
  public MobilePlaceManager( Environment env )
  {
    this.env = env;

    env.dir.addItem( "mpm", new MobilePlaceManagerExplorerItem( this ) );
  }

  public PlaceID getPosition( PlaceID mobilePlaceID )
  {
    return (PlaceID)mobilePlacePositions.get( mobilePlaceID );
  }

  public PlaceID putPosition( PlaceID mobilePlaceID, PlaceID position )
  {
    return (PlaceID)mobilePlacePositions.put( mobilePlaceID, position );
  }

  public PlaceID removePosition( PlaceID mobilePlaceID )
  {
    waitingAgents.remove( mobilePlaceID );

    return (PlaceID)mobilePlacePositions.remove( mobilePlaceID );
  }

  public void printStatus( PrintStream out )
  {
    printMobilePlacePositions( out );
    printWaitingAgents( out );
  }

  public void printMobilePlacePositions( PrintStream out )
  {
    out.println( "Mobile places positions: " );

    Iterator i = mobilePlacePositions.entrySet().iterator();

    for( int j = 1; i.hasNext(); j++ )
    {
      Map.Entry e = (Map.Entry)i.next();
      out.println( "  " + j + ") " + e.getKey() + " --> " + e.getValue() );
    }

    out.println();
  }

  /** Restituisce true se gli agenti destinati a destination devono attendere qui. */
  public boolean checkWaitCondition( PlaceID destination )
  {
    return destination instanceof MobilePlaceID
           && env.placeID.equals( destination.getHome() )
           && getPosition( destination ) == DISCONNECTED;
  }

  /** Aggiunge un agente alla liste degli agenti che attendono un place mobile.*/
  public void addWaitingAgent( AgentID agentID, PlaceID destination )
  {
    // Prendo il Set di agenti che aspettano
    Set agentIDSet = (Set)waitingAgents.get( destination );

    if( agentIDSet == null ) //Se non c'