Cafe.java

/*
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 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package com.cafe.apps;

/**
 *
 * @author Aditya
 */
public abstract class Cafe {
    
   protected String namaPembeli = "";
   
   public abstract String namaMakanan();
   public abstract int hargaMakanan();
   public abstract String namaMinuman();
   public abstract int hargaMinuman();
   
   public String getNamaPembeli(){
       return namaPembeli;
   }
   
   public String getNamaMakanan(){
       return namaMakanan();
   }
   
   public int getHargaMakanan(){
       return hargaMakanan();
   }
   
   public String getNamaMinuman(){
       return namaMinuman();
   }
   
   public int getHargaMinuman(){
       return hargaMinuman();
   }
   
}

Output.java

/*
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package com.cafe.apps;

/**
 *
 * @author Aditya
 */
class Output {

    public static void main(String[] args) {
        Pembeli Udin = new Pembeli();
        
        System.out.println("Hangout di Cafe Marjan\n");
        System.out.println("Udin memesan : ");
        System.out.println("Makanan : "+Udin.getNamaMakanan() + " "+Udin.getHargaMakanan());
        System.out.println("Minuman : "+Udin.getNamaMinuman() + " "+Udin.getHargaMinuman());
        System.out.println("Total : "+Udin.Total1());
        System.out.println("-----------------------------------------");
        
        Amir pembeli = new Amir();
        
        System.out.println("Amir memesan : ");
        System.out.println("Makanan : "+pembeli.getNamaMakanan() + ""+pembeli.getHargaMakanan());
        System.out.println("Minuman : "+pembeli.getNamaMinuman() + ""+pembeli.getHargaMinuman());
        System.out.println("Total : "+pembeli.Total2());
        System.out.println("-----------------------------------------");
        
        Fahri beli = new Fahri();
        
        System.out.println("Fahri memesan : ");
        System.out.println("Makanan : "+beli.getNamaMakanan() + ""+beli.getHargaMakanan());
        System.out.println("Minuman : "+beli.getNamaMinuman() + ""+beli.getHargaMinuman());
        System.out.println("Total : "+beli.Total3());
        System.out.println("-----------------------------------------");
        System.out.println("Total Keseluruhan : "+(Udin.Total1()+
                pembeli.Total2()+beli.Total3()));
}

        
    }

Pembeli.java

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package com.cafe.apps;

/**
 *
 * @author Aditya
 */
class Pembeli extends Cafe{
    
    int Total1;
    int Total2;
    int Total3;
    
    @Override
    public String getNamaPembeli(){
        return "Udin";
    }
    
    @Override
    public String namaMakanan(){
        return "Steak";
    }
    
    @Override
    public int hargaMakanan(){
        return 22000;
    }
    
    @Override
    public String namaMinuman(){
        return "Jus Alpukat";
    }
    
    @Override
    public int hargaMinuman(){
        return 7000;
    }
    
    public int Total1(){
        return hargaMakanan() + hargaMinuman();
}
    
}

    class Amir extends Cafe{
    
    @Override
    public String getNamaPembeli(){
        return "Amir";
    }
    
    @Override
    public String namaMakanan(){
        return "Baso Campur";
    }
    
    @Override
    public int hargaMakanan(){
        return 15000;
    }
    
    @Override
    public String namaMinuman(){
        return "Teh Manis Lemon";
    }
    
    @Override
    public int hargaMinuman(){
        return 6000;
    }
    
    public int Total2(){
        return hargaMakanan() + hargaMinuman();
    }
    
}

    class Fahri extends Cafe{
    
    @Override
    public String getNamaPembeli(){
        return "Fahri";
    }
    
    @Override
    public String namaMakanan(){
        return "Nasi Goreng Spesial";
    }
    
    @Override
    public int hargaMakanan(){
        return 20000;
    }
    
    @Override
    public String namaMinuman(){
        return "Teh Manis Biasa";
    }
    
    @Override
    public int hargaMinuman(){
        return 4000;
    }

    public int Total3(){
        return hargaMakanan() + hargaMinuman();
    }
    
}