Tutoriais - Programação Orientada a ObjetosDesenvolva um programa que simule uma máquina de vendas automática, utilizando o padrão de projeto Chain of Responsibility como base.
A máquina possui diversos slots, cada um capaz de receber um tipo de moeda diferente: R$ 0,01, R$ 0,05, R$ 0,10, R$ 0,25, R$ 0,50 e R$ 1,00.
A máquina deve receber moedas e delegar aos slots que capturem-nas.
Quando chegar ao valor do produto desejado, a máquina deve entregar o produto e informar o troco, caso houver.
/**
* Copyright (C) 2009/2025 - Cristiano Lehrer (cristiano@ybadoo.com.br)
* Ybadoo - Solucoes em Software Livre (www.ybadoo.com.br)
*
* Permission is granted to copy, distribute and/or modify this document
* under the terms of the GNU Free Documentation License, Version 1.3
* or any later version published by the Free Software Foundation; with
* no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.
* A copy of the license is included in the section entitled "GNU
* Free Documentation License".
*/
package com.ybadoo.tutoriais.poo;
/**
* Helper
*/
public enum Coin
{
ONE_PENCE, // R$ 0,01
FIVE_PENCE, // R$ 0,05
TEN_PENCE, // R$ 0,10
TWENTY_FIVE_PENCE, // R$ 0,25
FIFTY_PENCE, // R$ 0,50
ONE_POUND; // R$ 1,00
}/**
* Copyright (C) 2009/2025 - Cristiano Lehrer (cristiano@ybadoo.com.br)
* Ybadoo - Solucoes em Software Livre (www.ybadoo.com.br)
*
* Permission is granted to copy, distribute and/or modify this document
* under the terms of the GNU Free Documentation License, Version 1.3
* or any later version published by the Free Software Foundation; with
* no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.
* A copy of the license is included in the section entitled "GNU
* Free Documentation License".
*/
package com.ybadoo.tutoriais.poo;
import java.math.BigDecimal;
/**
* Handler
*/
public abstract class CoinHandler
{
/**
* Proximo slot da ATM
*/
protected CoinHandler successor;
/**
* Reconhecer o valor monetario da moeda
*
* @param coin moeda a ser analisada
* @return valor monetario da moeda
*/
public abstract BigDecimal recognize(Coin coin);
/**
* Configurar o proximo slot
*
* @param successor proximo slot
*/
public void setSuccessor(CoinHandler successor)
{
this.successor = successor;
}
}/**
* Copyright (C) 2009/2025 - Cristiano Lehrer (cristiano@ybadoo.com.br)
* Ybadoo - Solucoes em Software Livre (www.ybadoo.com.br)
*
* Permission is granted to copy, distribute and/or modify this document
* under the terms of the GNU Free Documentation License, Version 1.3
* or any later version published by the Free Software Foundation; with
* no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.
* A copy of the license is included in the section entitled "GNU
* Free Documentation License".
*/
package com.ybadoo.tutoriais.poo;
import java.math.BigDecimal;
/**
* Concrete Handler (R$ 0,01)
*/
public class OnePenceHandler extends CoinHandler
{
/* (non-Javadoc)
* @see com.ybadoo.tutoriais.poo.CoinHandler#recognize(com.ybadoo.tutoriais.poo.Coin)
*/
public BigDecimal recognize(Coin coin)
{
if(Coin.ONE_PENCE.equals(coin))
{
System.out.println("Reconhecido R$ 0,01");
return new BigDecimal(0.01);
}
else if(successor != null)
{
return successor.recognize(coin);
}
else
{
return new BigDecimal(0.0);
}
}
}/**
* Copyright (C) 2009/2025 - Cristiano Lehrer (cristiano@ybadoo.com.br)
* Ybadoo - Solucoes em Software Livre (www.ybadoo.com.br)
*
* Permission is granted to copy, distribute and/or modify this document
* under the terms of the GNU Free Documentation License, Version 1.3
* or any later version published by the Free Software Foundation; with
* no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.
* A copy of the license is included in the section entitled "GNU
* Free Documentation License".
*/
package com.ybadoo.tutoriais.poo;
import java.math.BigDecimal;
/**
* Concrete Handler (R$ 0,05)
*/
public class FivePenceHandler extends CoinHandler
{
/* (non-Javadoc)
* @see com.ybadoo.tutoriais.poo.CoinHandler#recognize(com.ybadoo.tutoriais.poo.Coin)
*/
public BigDecimal recognize(Coin coin)
{
if(Coin.FIVE_PENCE.equals(coin))
{
System.out.println("Reconhecido R$ 0,05");
return new BigDecimal(0.05);
}
else if(successor != null)
{
return successor.recognize(coin);
}
else
{
return new BigDecimal(0.0);
}
}
}/**
* Copyright (C) 2009/2025 - Cristiano Lehrer (cristiano@ybadoo.com.br)
* Ybadoo - Solucoes em Software Livre (www.ybadoo.com.br)
*
* Permission is granted to copy, distribute and/or modify this document
* under the terms of the GNU Free Documentation License, Version 1.3
* or any later version published by the Free Software Foundation; with
* no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.
* A copy of the license is included in the section entitled "GNU
* Free Documentation License".
*/
package com.ybadoo.tutoriais.poo;
import java.math.BigDecimal;
/**
* Concrete Handler (R$ 0,10)
*/
public class TenPenceHandler extends CoinHandler
{
/* (non-Javadoc)
* @see com.ybadoo.tutoriais.poo.CoinHandler#recognize(com.ybadoo.tutoriais.poo.Coin)
*/
public BigDecimal recognize(Coin coin)
{
if(Coin.TEN_PENCE.equals(coin))
{
System.out.println("Reconhecido R$ 0,10");
return new BigDecimal(0.10);
}
else if(successor != null)
{
return successor.recognize(coin);
}
else
{
return new BigDecimal(0.0);
}
}
}/**
* Copyright (C) 2009/2025 - Cristiano Lehrer (cristiano@ybadoo.com.br)
* Ybadoo - Solucoes em Software Livre (www.ybadoo.com.br)
*
* Permission is granted to copy, distribute and/or modify this document
* under the terms of the GNU Free Documentation License, Version 1.3
* or any later version published by the Free Software Foundation; with
* no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.
* A copy of the license is included in the section entitled "GNU
* Free Documentation License".
*/
package com.ybadoo.tutoriais.poo;
import java.math.BigDecimal;
/**
* Concrete Handler (R$ 0,25)
*/
public class TwentyFivePenceHandler extends CoinHandler
{
/* (non-Javadoc)
* @see com.ybadoo.tutoriais.poo.CoinHandler#recognize(com.ybadoo.tutoriais.poo.Coin)
*/
public BigDecimal recognize(Coin coin)
{
if(Coin.TWENTY_FIVE_PENCE.equals(coin))
{
System.out.println("Reconhecido R$ 0,25");
return new BigDecimal(0.25);
}
else if(successor != null)
{
return successor.recognize(coin);
}
else
{
return new BigDecimal(0.0);
}
}
}/**
* Copyright (C) 2009/2025 - Cristiano Lehrer (cristiano@ybadoo.com.br)
* Ybadoo - Solucoes em Software Livre (www.ybadoo.com.br)
*
* Permission is granted to copy, distribute and/or modify this document
* under the terms of the GNU Free Documentation License, Version 1.3
* or any later version published by the Free Software Foundation; with
* no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.
* A copy of the license is included in the section entitled "GNU
* Free Documentation License".
*/
package com.ybadoo.tutoriais.poo;
import java.math.BigDecimal;
/**
* Concrete Handler (R$ 0,50)
*/
public class FiftyPenceHandler extends CoinHandler
{
/* (non-Javadoc)
* @see com.ybadoo.tutoriais.poo.CoinHandler#recognize(com.ybadoo.tutoriais.poo.Coin)
*/
public BigDecimal recognize(Coin coin)
{
if(Coin.FIFTY_PENCE.equals(coin))
{
System.out.println("Reconhecido R$ 0,50");
return new BigDecimal(0.50);
}
else if(successor != null)
{
return successor.recognize(coin);
}
else
{
return new BigDecimal(0.0);
}
}
}/**
* Copyright (C) 2009/2025 - Cristiano Lehrer (cristiano@ybadoo.com.br)
* Ybadoo - Solucoes em Software Livre (www.ybadoo.com.br)
*
* Permission is granted to copy, distribute and/or modify this document
* under the terms of the GNU Free Documentation License, Version 1.3
* or any later version published by the Free Software Foundation; with
* no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.
* A copy of the license is included in the section entitled "GNU
* Free Documentation License".
*/
package com.ybadoo.tutoriais.poo;
import java.math.BigDecimal;
/**
* Concrete Handler (R$ 1,00)
*/
public class OnePoundHandler extends CoinHandler
{
/* (non-Javadoc)
* @see com.ybadoo.tutoriais.poo.CoinHandler#recognize(com.ybadoo.tutoriais.poo.Coin)
*/
public BigDecimal recognize(Coin coin)
{
if(Coin.ONE_POUND.equals(coin))
{
System.out.println("Reconhecido R$ 1,00");
return new BigDecimal(1.0);
}
else if(successor != null)
{
return successor.recognize(coin);
}
else
{
return new BigDecimal(0.0);
}
}
}/**
* Copyright (C) 2009/2025 - Cristiano Lehrer (cristiano@ybadoo.com.br)
* Ybadoo - Solucoes em Software Livre (www.ybadoo.com.br)
*
* Permission is granted to copy, distribute and/or modify this document
* under the terms of the GNU Free Documentation License, Version 1.3
* or any later version published by the Free Software Foundation; with
* no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.
* A copy of the license is included in the section entitled "GNU
* Free Documentation License".
*/
package com.ybadoo.tutoriais.poo;
import java.math.BigDecimal;
import java.text.NumberFormat;
import java.util.Locale;
/**
* Automated Teller Machine (ATM)
*/
public class ATM
{
/**
* Preco a ser cobrado pela ATM
*/
private BigDecimal price;
/**
* Primeiro slot da ATM
*/
private CoinHandler slot;
/**
* Valor depositado na ATM pelo usuario
*/
private BigDecimal total;
/**
* Construtor para inicializar o preco a ser cobrado pela ATM
*
* @param price preco a ser cobrado pela ATM
*/
public ATM(BigDecimal price)
{
this.price = price;
total = new BigDecimal(0.0);
NumberFormat nf = NumberFormat.getInstance(new Locale("pt", "BR"));
System.out.println("Preço a ser cobrado: R$ " + nf.format(price));
slot = new OnePenceHandler();
CoinHandler fivePence = new FivePenceHandler();
CoinHandler tenPence = new TenPenceHandler();
CoinHandler twentyFivePence = new TwentyFivePenceHandler();
CoinHandler fiftyPence = new FiftyPenceHandler();
CoinHandler onePound = new OnePoundHandler();
slot.setSuccessor(fivePence);
fivePence.setSuccessor(tenPence);
tenPence.setSuccessor(twentyFivePence);
twentyFivePence.setSuccessor(fiftyPence);
fiftyPence.setSuccessor(onePound);
}
/**
* Depositar uma moeda
*
* @param coin moeda depositada pelo usuario na ATM
*/
public void deposit(Coin coin)
{
total = total.add(slot.recognize(coin));
NumberFormat nf = NumberFormat.getInstance(new Locale("pt", "BR"));
if(total.doubleValue() < price.doubleValue())
{
System.out.println("Falta R$ " + nf.format(price.subtract(total)));
}
else if(total.doubleValue() == price.doubleValue())
{
System.out.println("Obrigado pela sua preferência!");
}
else if(total.doubleValue() > price.doubleValue())
{
System.out.println("Obrigado pela sua preferência!");
System.out.println("Seu troco á de R$ " + nf.format(total.subtract(price)));
}
}
}/**
* Copyright (C) 2009/2025 - Cristiano Lehrer (cristiano@ybadoo.com.br)
* Ybadoo - Solucoes em Software Livre (www.ybadoo.com.br)
*
* Permission is granted to copy, distribute and/or modify this document
* under the terms of the GNU Free Documentation License, Version 1.3
* or any later version published by the Free Software Foundation; with
* no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.
* A copy of the license is included in the section entitled "GNU
* Free Documentation License".
*/
package com.ybadoo.tutoriais.poo;
import java.math.BigDecimal;
/**
* Teste da aplicacao
*/
public class Application
{
/**
* Metodo principal da linguagem de programacao Java
*
* @param args argumentos da linha de comando (nao utilizado)
*/
public static void main(String[] args)
{
// Preço a ser cobrado: R$ 2,02
ATM atm = new ATM(new BigDecimal(2.02));
// Reconhecido R$ 1,00
// Falta R$ 1,02
atm.deposit(Coin.ONE_POUND);
// Reconhecido R$ 0,50
// Falta R$ 0,52
atm.deposit(Coin.FIFTY_PENCE);
// Reconhecido R$ 0,25
// Falta R$ 0,27
atm.deposit(Coin.TWENTY_FIVE_PENCE);
// Reconhecido R$ 0,10
// Falta R$ 0,17
atm.deposit(Coin.TEN_PENCE);
// Reconhecido R$ 0,10
// Falta R$ 0,07
atm.deposit(Coin.TEN_PENCE);
// Reconhecido R$ 0,05
// Falta R$ 0,02
atm.deposit(Coin.FIVE_PENCE);
// Reconhecido R$ 0,01
// Falta R$ 0,01
atm.deposit(Coin.ONE_PENCE);
// Reconhecido R$ 0,01
// Obrigado pela sua preferência!
atm.deposit(Coin.ONE_PENCE);
}
}Ybadoo - Soluções em Software Livre • Copyright 2009/2025 • 