Sunday, 24 November 2013

Memento Design pattern - Implementation


Click here to watch in Youtube : https://www.youtube.com/watch?v=ZjouanHQmdk

Click the below Image to Enlarge
Memento Design pattern - Implementation
Memento Design pattern - Class Diagram








































LedTV.java

public class LedTV
{
private String  size;
private String  price;
private boolean usbSupport;

public LedTV( String size, String price, boolean usbSupport )
{
super();
this.size = size;
this.price = price;
this.usbSupport = usbSupport;
}

public String getSize()
{
return size;
}

public void setSize( String size )
{
this.size = size;
}

public String getPrice()
{
return price;
}

public void setPrice( String price )
{
this.price = price;
}

public boolean isUsbSupport()
{
return usbSupport;
}

public void setUsbSupport( boolean usbSupport )
{
this.usbSupport = usbSupport;
}

@Override
public String toString()
{
return "LedTV [size=" + size + ", price=" + price + ", usbSupport=" + usbSupport + "]";
}

}


Memento.java

public class Memento
{
private LedTV ledTV;

public Memento( LedTV ledTV )
{
super();
this.ledTV = ledTV;
}

public LedTV getLedTV()
{
return ledTV;
}

public void setLedTV( LedTV ledTV )
{
this.ledTV = ledTV;
}

@Override
        public String toString()
        {
       return "Memento [ledTV=" + ledTV + "]";
        }

}

Caretaker.java

import java.util.ArrayList;
import java.util.List;
/*
 * Store Room
 */
public class Caretaker
{
private List<Memento> ledTvList = new ArrayList<Memento>();

public void addMemento( Memento m )
{
ledTvList.add(m);
System.out.println("LED TV's snapshots Maintained by CareTaker :" + ledTvList);
}

public Memento getMemento( int index )
{
return ledTvList.get(index);
}
}


Originator.java

/*
 * Hall
 */
public class Originator
{
LedTV ledTV;

public LedTV getLedTV()
{
return ledTV;
}

public void setLedTV( LedTV ledTV )
{
this.ledTV = ledTV;
}

public Memento createMemento()
{
return new Memento(ledTV);
}

public void setMemento( Memento memento )
{
ledTV = memento.getLedTV();
}

@Override
        public String toString()
        {
       return "Originator [ledTV=" + ledTV + "]";
        }

}

MementoClient.java

public class MementoClient
{

public static void main( String[] args )
{
Originator originator = new Originator();
originator.setLedTV(new LedTV("42 inch", "60000Rs", false));

Caretaker caretaker = new Caretaker();
caretaker.addMemento(originator.createMemento());

originator.setLedTV(new LedTV("46 inch", "80000Rs", true));
caretaker.addMemento(originator.createMemento());

originator.setLedTV(new LedTV("50 inch", "100000Rs", true));
System.out.println("\nOrignator current state : " + originator);

System.out.println("\nOriginator restoring to 42 inch LED TV...");

originator.setMemento(caretaker.getMemento(0));

System.out.println("\nOrignator current state : " + originator);

}

}

Output

LED TV's snapshots Maintained by CareTaker :[Memento [ledTV=LedTV [size=42 inch, price=60000Rs, usbSupport=false]]]
LED TV's snapshots Maintained by CareTaker :[Memento [ledTV=LedTV [size=42 inch, price=60000Rs, usbSupport=false]], Memento [ledTV=LedTV [size=46 inch, price=80000Rs, usbSupport=true]]]

Orignator current state : Originator [ledTV=LedTV [size=50 inch, price=100000Rs, usbSupport=true]]

Originator restoring to 42 inch LED TV...

Orignator current state : Originator [ledTV=LedTV [size=42 inch, price=60000Rs, usbSupport=false]]

See also:

  • Momento Design pattern - Introduction
  • Momento Design pattern - Real time Example
  • Memento Design pattern - Class Diagram
  • Memento Design pattern - Sequence Diagram
  • Momento Design pattern - KeyPoints
  • All Design Patterns Links
  • No comments:

    Post a Comment

    Google+ Followers

    Google+ Badge