Design Patterns Java™ Workbook

Appendix B. Solutions

SOLUTION 10.4....................................................................................................................................

The contents of Tub.java should look something like:

package com.oozinoz.chemical;
import com.oozinoz.machine.*;
public class Tub
{
protected String id;
protected Mediator mediator;

public Tub(String id, Mediator mediator)
{
this.id = id;
}

public Machine getMachine()
{
return mediator.getMachine(this);
}

public void setMachine(Machine machine)
{
mediator.set(this, machine);
}

public String toString()
{
return id;
}
}

SOLUTION 10.5....................................................................................................................................

• The FACADE pattern may help to refactor a large application.


• The BRIDGE pattern moves abstract operations to an interface.


• The OBSERVER pattern may appear as you refactor code to support an MVC
  architecture.


• The FLYWEIGHT pattern extricates the immutable part of an object so that this part can
  be shared.


• The BUILDER pattern moves the construction logic for an object outside the class to
  instantiate.


• The FACTORY METHOD pattern lets you reduce the amount of responsibility in a class
  hierarchy by moving an aspect of behavior to a parallel hierarchy.


• The STATE and STRATEGY patterns let you move state-specific and strategy-specific
  behavior into separate classes.