Hotel Management System

import java.util.Calendar;
import java.util.Date;
import java.util.Scanner;
class WrongInputException extends Exception
{
	String str1=new String();
	WrongInputException(String str)
	{
		str1=str;
	}
	public String toString()
	{
		return("WrongInputException -> "+str1);
	}
}
class Customer
{
	String name=new String();
	String add=new String();
	String no=new String();
	void display_Customer()
	{
		System.out.println("Name- "+name);
		System.out.println("Address- "+add);
		System.out.println("Contact No.- "+no);
    }
}
class Food
{
	static final String b[]=new String[6];
	static final int rate[]=new int[6];
	int f[]=new int[6];
	int i;
	Food()
	{
		for(i=0;i<6;i++)
		{
			f[i]=0;
		}
		for(i=0;i<6;i++)
		{
			b[i]=new String();
		}
		b[0]="Bread Butter        ";
		b[1]="Bread Omelet        ";
		b[2]="Coffee              ";
		b[3]="Tea                 ";
		b[4]="Mineral Water       ";
		b[5]="Ice Cream           ";
		rate[0]=40;
		rate[1]=55;
		rate[2]=35;
		rate[3]=30;
		rate[4]=25;
		rate[5]=50;
	
	}
	void food_billing()
	{
		System.out.println(" Item                   Quantity          Price");
		for(i=0;i<6;i++)
		{
			if(f[i]!=0)
			{
				System.out.println(b[i]+"    "+f[i]+"                 "+(rate[i]*f[i]));
			}
		}
		System.out.println("-----------------------------------------------------------------------------");
	}
}
class Room
{
	static int vacant=20;
	int room_no;
	Customer c=new Customer();
	Calendar in=Calendar.getInstance();
	final int base=1500;
	Food food=new Food();
	int food_bill=0;
	double tax;
	double total_bill;
	
	void display()
	{
		System.out.println("Room No.- "+room_no);
		c.display_Customer();
	}
	void billing(long x)
	{	
		int i;
		for(i=0;i<6;i++)
		{
			food_bill+=food.f[i]*Food.rate[i];
		}
		tax=0.19*((base*x)+food_bill);
		total_bill=(base*x)+food_bill+tax;
		Date d1=new Date();
		System.out.println("-----------------------------------------------------------------------------");
		System.out.println("-----------------------------------------------------------------------------");
		System.out.println("                            Hotel Transylvania                               ");
		System.out.println("                               New Delhi                                     ");
		System.out.println("                          +1234567890,9876543210                             \n");
		System.out.println("                                                   Dated: "+d1+"\n");
		System.out.println("Customer Details:\n");
		c.display_Customer();
		System.out.println("No. of Days = "+x);
		System.out.println("------------------------------Room Billing-----------------------------------");
		System.out.println("Base Price For "+x+" Days          ---------- "+(base*x)+" Rs.");
		System.out.println("------------------------------Food Billing-----------------------------------");
		food.food_billing();
		System.out.println("Total Food Price               ---------- "+food_bill+" Rs.");
		System.out.println("Total Tax (19%)                ---------- "+tax+" Rs.");
		System.out.println("Total Bill                     ---------- "+total_bill+" Rs.");
		System.out.println("-----------------------------------------------------------------------------");
		System.out.println("-----------------------------------------------------------------------------");
	}
}
public class Hotel 
{
	public static void main(String args[])
	{
		WrongInputException ex=new WrongInputException("Invalid Choice!");
		Room r[]=new Room[20];
		int i;
		for(i=0;i<20;i++)
		{
			r[i]=new Room();
		}
		int ch;
		Date d=new Date();
		System.out.println("                            Hotel Transylvania                               ");
		System.out.println("                               New Delhi                                     ");
		System.out.println("                          +1234567890,9876543210                             \n");
		System.out.println("                                                   Dated: "+d+"\n");
		Scanner scan=new Scanner(System.in);
		int x1=1;
		while(x1!=0)
		{
		System.out.println("-----------------------------------------------------------------------------");
		System.out.println("Enter your choice: \n1.Check In\n2.Customer Info\n3.Order Food\n4.Check Out\n5.Exit");
		System.out.println("-----------------------------------------------------------------------------");
		ch=scan.nextInt();
		switch(ch)
		{
		case 1:	if(Room.vacant==0)
				{
					System.out.println("Rooms Not Available!");
					System.out.println("Thanks for Your Visit!");
					break;
				}
		        System.out.println("No. of Rooms Vacant = "+Room.vacant);
				System.out.println("Rooms Vacant:");
				for(i=0;i<20;i++)
				{	
					if(r[i].room_no!=i+1)
					{
						System.out.println("              Room No."+(i+1));
					}
				}
				System.out.println("Enter the Room No. to be Alloted");
				System.out.println("             OR                 ");
				System.out.println("To go back to Main Menu--Enter 0");
				int allot=scan.nextInt();
				scan.nextLine();
				if(allot==0)
				{
					break;
				}
				else if(allot>20)
					{
						try
						{
							throw ex;
						}
						catch(WrongInputException e)
						{
							System.out.println(e);
							break;
						}
					}
					else
					{
						if(r[allot-1].room_no==allot)
						{
							System.out.println("Room Not Available");
							break;
						}
						r[allot-1].room_no=allot;
						Customer c1=new Customer();
						System.out.println("Enter the Customer Name");
						c1.name=scan.nextLine();
						System.out.println("Enter the Address");
						c1.add=scan.nextLine();
						System.out.println("Enter the Contact No.");
						c1.no=scan.nextLine();
						r[allot-1].c=c1;
						Calendar date=Calendar.getInstance();
						System.out.println("Enter the Date Today in Numerical Form:");
						System.out.println("Day:");
						int d3=scan.nextInt();
						System.out.println("Month:");
						int d2=scan.nextInt();
						System.out.println("Year:");
						int d1=scan.nextInt();
						date.set(d1,d2,d3);
						r[allot-1].in=date;
						System.out.println("Room No. "+allot+" Alloted!");
						Room.vacant--;
					}
					break;
				
		case 2: System.out.println("Enter Room No. For Information");
				int info=scan.nextInt();
				if(r[info-1].room_no!=info)
				{
					System.out.println("Room Is Vacant!");
					break;
				}
				r[info-1].display();
				break;
		case 3: System.out.println("Enter your Room No.");
				int no=scan.nextInt();
				if(r[no-1].room_no!=no)
				{
					System.out.println("Room Is Vacant!");
					break;
				}
			    System.out.println("Choose the Index You Want to order:");
			    System.out.println("   Item              Price");
				for(i=0;i<6;i++)
				{
					System.out.println((i+1)+". "+Food.b[i]+Food.rate[i]+" Rs.");
				}
				int ch1=scan.nextInt();
				try
				{
					if((ch1<1)||(ch1>6))
					{
						throw ex;
					}
		        }
				catch(WrongInputException e)
				{
					System.out.println(e);
					break;
				}
				System.out.println("Enter the Quantity");
				int quan=scan.nextInt();
				r[no-1].food.f[ch1-1]+=quan;
				System.out.println("Item Ordered Successfully");
				break;
				
		case 4: System.out.println("Enter Your Room No.");
				int unallot=scan.nextInt();
				if(r[unallot-1].room_no!=unallot)
				{
					System.out.println("Room Is Vacant!");
					break;
				}
				r[unallot-1].display();
				Calendar date1=Calendar.getInstance();
				System.out.println("Enter the Date Today in Numerical Form:");
				System.out.println("Day:");
				int d6=scan.nextInt();
				System.out.println("Month:");
				int d5=scan.nextInt();
				System.out.println("Year:");
				int d4=scan.nextInt();
				date1.set(d4,d5,d6);
				long diff=date1.getTimeInMillis()-r[unallot-1].in.getTimeInMillis();
				long x=diff/(24*60*60*1000);
				r[unallot-1].billing(x);
				System.out.println("Thanks For Your Visit");
				r[unallot-1]=new Room();
				Room.vacant++;
				break;
		
			
		case 5: x1=0;
				break;
		default:try
				{
					throw ex;
				}
				catch(WrongInputException e)
				{
					System.out.println(e);
				}
	  }
	}
  }
}