远程对象工厂设计模式

//Flight.java

 

package flight;

import java.rmi.*;

public interface Flight extends Remote{

  //读取航班号

  public String getFlightNumber()throws RemoteException;

  //读取始发站

  public String getOrigin()throws RemoteException;

  //读取终点站

  public String getDestination()throws RemoteException;

  //读取计划出发时间

  public String getSkdDeparture()throws RemoteException;

  //读取计划到达时间

  public String getSkdArrival()throws RemoteException;

  public void setOrigin(String origin)throws RemoteException;

  public void setDestination(String destination)throws RemoteException;

  public void setSkdDeparture(String skdDeparture)throws RemoteException;

  public void setSkdArrival(String skdArrival)throws RemoteException; 

}

//FlightFactory.java 

package flight;

import java.rmi.*;

public interface FlightFactory extends Remote{

  public Flight getFlight(String flightNumber)throws RemoteException;

}

// 

FlightImpl.java

 

package flight;

 

import java.rmi.*;

import java.rmi.server.*;

public class FlightImpl extends UnicastRemoteObject implements Flight{

  protected String flightNumber;

  protected String origin;

  protected String destination;

  protected String skdDeparture;

  protected String skdArrival;

  public FlightImpl(String aFlightNumber, String anOrigin,

          String aDestination, String aSkdDeparture, String aSkdArrival)

          throws RemoteException{

    flightNumber = aFlightNumber;

    origin = anOrigin;

    destination = aDestination;

    skdDeparture = aSkdDeparture;

    skdArrival = aSkdArrival;

  }

  public String getFlightNumber()throws RemoteException{

    System.out.println("调用getFilghtNumber()，返回"+flightNumber);

    return flightNumber;

  }

  public String getOrigin()throws RemoteException{

    return origin;

  }

  public String getDestination()throws RemoteException{

    return destination;

  }

  public String getSkdDeparture()throws RemoteException{

    return skdDeparture;

  }

  public String getSkdArrival()throws RemoteException{

    return skdArrival;

  }

  public void setOrigin(String origin)throws RemoteException{

    this.origin=origin;

  }

  public void setDestination(String destination)throws RemoteException{

    this.destination=destination;

  }

  

  public void setSkdDeparture(String skdDeparture)throws RemoteException{

    this.skdDeparture=skdDeparture;

  }

  public void setSkdArrival(String skdArrival)throws RemoteException{

    this.skdArrival=skdArrival;

  }

}

 

//FlightFactoryImpl.java 

package flight;

import java.rmi.*;

import java.rmi.server.*;

import java.util.*;

public class FlightFactoryImpl extends UnicastRemoteObject

                                     implements FlightFactory{

    protected Hashtable<String,Flight> flights; //存放Flight对象的缓存

    public FlightFactoryImpl()throws RemoteException{

        flights = new Hashtable<String,Flight>();

    }

    public Flight getFlight(String flightNumber)throws RemoteException{

      Flight flight = flights.get(flightNumber);

      if (flight != null) return flight;

      flight = new FlightImpl(flightNumber, null, null, null, null);

      flights.put(flightNumber, flight);

      return flight;

    }

}

 //SimpleClient.java

package flight;

import java.rmi.*;

import javax.naming.*;

public class SimpleClient{

  public static void main(String[] args){

    String url="rmi://localhost/";

    try{

      Context namingContext=new InitialContext();

      FlightFactory factory=(FlightFactory)namingContext.lookup(url+"FlightFactory");

      Flight flight1 = factory.getFlight("795");

      flight1.setOrigin("Shanghai");

      flight1.setDestination("Beijing");

      System.out.println("Flight "+flight1.getFlightNumber()+":");

      System.out.println("From "+flight1.getOrigin()+" to "+

                                        flight1.getDestination());

      

      Flight flight2 = factory.getFlight("795");

      System.out.println("Flight "+flight2.getFlightNumber()+":");

      System.out.println("From "+flight2.getOrigin()+" to "+

                                        flight2.getDestination());

      System.out.println("flight1是"+flight1.getClass().getName()+"的实例");

      System.out.println("flight2是"+flight2.getClass().getName()+"的实例");

      System.out.println("flight1==flight2:"+(flight1==flight2));

      System.out.println("flight1.equals(flight2):"+(flight1.equals(flight2)));

    }catch(Exception e){

       e.printStackTrace();

    }

  }

}

 

//SimpleServer.java 

package flight;

import java.rmi.*;

import javax.naming.*;

public class SimpleServer{

  public static void main( String args[] ){

    try{

       FlightFactory factory  = new FlightFactoryImpl();

 

       Context namingContext=new InitialContext();

       namingContext.rebind( "rmi:FlightFactory", factory );

        

       System.out.println( "服务器注册了一个FlightFactory对象" );

    }catch(Exception e){

       e.printStackTrace();

    } 

  }

}