person.java

用java模拟的电梯程序,可以选择有几层楼,一共有几个人在哪几层等电梯,可以不断的增加等电梯的人数,并看电梯如何以设定的方式运行.

// Person.java
// Person riding the elevator
package com.Anance.elevator.model;

// Java core packages
import java.util.*;

// Deitel packages
import com.Anance.elevator.event.*;

public class Person extends Thread implements DoorListener {

   // identification number
   private int ID = -1;

   // represents whether Person is moving or waiting
   private boolean moving;

   // reference to Location (either on Floor or in Elevator)
   private Location location;

   // listener object for PersonMoveEvents
   private PersonMoveListener personMoveListener;

   // time in milliseconds to walk to Button on Floor
   private static final int TIME_TO_WALK = 3000;

   // maximum time Person will wait for Elevator (10 minutes)
   private static final int TIME_WAITING = 10 * 60 * 1000;

   // types of messages Person may send
   public static final int PERSON_CREATED = 1;
   public static final int PERSON_ARRIVED = 2;
   public static final int PERSON_ENTERING_ELEVATOR = 3;
   public static final int PERSON_PRESSING_BUTTON = 4;
   public static final int PERSON_EXITING_ELEVATOR = 5;
   public static final int PERSON_EXITED = 6;

   // Person constructor set initial location
   public Person( int identifier, Location initialLocation )
   {
      super();

      ID = identifier; // assign unique identifier
      location = initialLocation; // set Floor Location
      moving = true; // start moving toward Button on Floor
   }

   // set listener for PersonMoveEvents
   public void setPersonMoveListener(
      PersonMoveListener listener )
   {
      personMoveListener = listener;
   }

   // invoked when Door has opened
   public void doorOpened( DoorEvent doorEvent )
   {
      // set Person on Floor where Door opened
      setLocation( doorEvent.getLocation() );

      // interrupt Person's sleep method in run method and 
      // Elevator's ride method
      interrupt();
   }

   // invoked when Door has closed
   public void doorClosed( DoorEvent doorEvent ) {}

   // set Person Location
   private void setLocation( Location newLocation )
   {
      location = newLocation;
   }

   // get current Location
   private Location getLocation()
   {
      return location;
   }

   // get identifier
   public int getID()
   {
      return ID;
   }

   // set if Person should move
   public void setMoving( boolean personMoving )
   {
      moving = personMoving;
   }

   // get if Person should move
   public boolean isMoving()
   {
      return moving;
   }

   // Person either rides or waits for Elevator
   public void run()
   {
      sendPersonMoveEvent( PERSON_CREATED );

      // walk to Elevator
      pauseThread( TIME_TO_WALK );
      setMoving( false );

      // Person arrived at Floor Button
      sendPersonMoveEvent( PERSON_ARRIVED );

      // get current Door on Floor
      Door currentFloorDoor = location.getDoor();

      // determine if Door on Floor is open
      try {

         boolean doorOpen = currentFloorDoor.isDoorOpen();

         // if Door on Floor is closed
         if ( !doorOpen ) {

            // press Floor Button
            sendPersonMoveEvent( PERSON_PRESSING_BUTTON );
            pauseThread( 1000 );

            // register for Floor Door's doorOpen event
            currentFloorDoor.addDoorListener( this );

            // press Floor's Button to request Elevator
            Button floorButton = getLocation().getButton();
            floorButton.pressButton( getLocation() );

            // wait for Floor's Door to open
            sleep( TIME_WAITING );

            // unregister with Floor's Door if too long
            currentFloorDoor.removeDoorListener( this );
         }

         // if Door on Floor is open, ride Eelevator
         else
            enterAndRideElevator();
      }

      // handle exception when interrupted from waiting
      catch ( InterruptedException interruptedException ) {

         // Person unregisters for Floor's Door doorOpen event
         currentFloorDoor.removeDoorListener( this );

         // enter and ride Elevator when Door on Floor opens,
         pauseThread( 1000 );
         enterAndRideElevator();
      }

      // waiting for Elevator's Door to open takes a second
      pauseThread( 1000 );

      // begin walking away from Elevator
      setMoving( true );

      // Person exits Elevator
      sendPersonMoveEvent( PERSON_EXITING_ELEVATOR );

      // walking from elevator takes five seconds
      pauseThread( 2 * TIME_TO_WALK );

      // Person exits simulation
      sendPersonMoveEvent( PERSON_EXITED );

   } // end method run

   // Person enters Elevator
   private void enterAndRideElevator()
   {
      // Person enters Elevator
      sendPersonMoveEvent( PERSON_ENTERING_ELEVATOR );

      // set Person Location to Elevator
      Floor floorLocation = ( Floor ) getLocation();
      setLocation( 
         floorLocation.getElevatorShaft().getElevator() );

      // Person takes one second to enter Elevator
      pauseThread( 1000 );

      // register for Elevator's Door's doorOpen event
      Door elevatorDoor = getLocation().getDoor();
      elevatorDoor.addDoorListener( this );

      // pressing Elevator Button takes one second
      sendPersonMoveEvent( PERSON_PRESSING_BUTTON );
      pauseThread( 1000 );

      // get Elevator's Button
      Button elevatorButton = getLocation().getButton();

      // press Elevator's Button
      elevatorButton.pressButton( location );

      // Door closing takes one second
      pauseThread( 1000 );

      // ride in Elevator
      Elevator elevator = ( Elevator ) getLocation();
      elevator.ride();

      // Person finished riding Elevator
      
      // unregister for Elevator's Door's doorOpen event
      elevatorDoor.removeDoorListener( this );

   } // end method enterAndRideElevator

   // pause thread for desired number of milliseconds
   private void pauseThread( int milliseconds )
   {
      try {
         sleep( milliseconds );
      }

      // handle exception if interrupted when paused
      catch ( InterruptedException interruptedException ) {
         interruptedException.printStackTrace();
      }
   } // end method pauseThread

   // send PersonMoveEvent to listener, depending on event type
   private void sendPersonMoveEvent( int eventType )
   {
      // create new event
      PersonMoveEvent event = 
         new PersonMoveEvent( this, getLocation(), getID() );

      // send Event to this listener, depending on eventType
      switch ( eventType ) {

         // Person has been created
         case PERSON_CREATED:
            personMoveListener.personCreated( event );
            break;

         // Person arrived at Elevator
         case PERSON_ARRIVED:
            personMoveListener.personArrived( event );
            break;

         // Person entered Elevator
         case PERSON_ENTERING_ELEVATOR:
            personMoveListener.personEntered( event );
            break;

         // Person pressed Button object
         case PERSON_PRESSING_BUTTON:
            personMoveListener.personPressedButton( event );
            break;

         // Person exited Elevator
         case PERSON_EXITING_ELEVATOR:
            personMoveListener.personDeparted( event );
            break;

         // Person exited simulation
         case PERSON_EXITED:
            personMoveListener.personExited( event );
            break;

         default:
            break;
      }
   } // end method sendPersonMoveEvent
}