package DP;

import org.apache.log4j.Logger;
import junit.framework.Assert;
import junit.framework.TestCase;

class ClassicSingleton {
 private static ClassicSingleton instance = null;

 protected ClassicSingleton() {
  // Exists only to defeat instantiation.
 }

 public static ClassicSingleton getInstance() {
  if (instance == null) {
   instance = new ClassicSingleton();

//抽象产品角色
interface BenzFactory{
 public void produceSportCar();
 public void produceBusinessCar();
}
//具体产品角色
class Benz implements BenzFactory{
 public void produceSportCar(){
  System.out.println("Bmw SportCar was produced");
 }
 public void produceBusinessCar(){
  System.out.println("Bmw BusinessCar was produced");

package DP;

//抽象工厂角色
interface AbstractFactory {
 public Car produceCar();
}

//具体工厂角色
class BenzFactory implements AbstractFactory {
 public Car produceCar() {
  return new Benz();
 }
}

//具体工厂角色
class BmwFactory implements AbstractFactory{
 public Car produceCar() {
  return new Bmw();
 }
}

package DP;

//抽象产品角色
interface Car{
 public void produce();
}

//具体产品角色
class Benz implements Car{
 public void produce(){
  System.out.println("Benz was produced");
 }
}
class Bmw implements Car{
 public void produce(){
  System.out.println("Bmw was produced");
 }
}
class Audi implements Car{