invoice.java

import java.util.*;

class Client{
		int id,hours;
		String address,name;
		double cons;
		Client(String name,int id,String addr,int hours){
			this.id = id;
			this.name = name;
			this.address = addr;
			this.hours = hours;
			this.cons = 1.08*Invoice.RATE*hours;
		}
		public void display(){
			System.out.println("\nClient #id: "+this.id);
			System.out.println("Address: "+this.address);
			System.out.println("Name: "+this.name);
			System.out.println("Hours worked: "+this.hours);
			System.out.println("Total amount of bill: "+this.cons);
		}
	}

class Invoice{

	private static final String MENU = "\n1. Add Client\n2. Create Invoice\n3. Quit\nEnter your choice: ";
	public static final int RATE = 200;

	public static void main(String[] args){
		String name,addr;
		int id,hours;
		int ch;
		Scanner sc = new Scanner(System.in);
		HashMap<String,Client> hm = new HashMap<String,Client>();
		while(true){
			System.out.println(MENU);
			ch = sc.nextInt();
			switch(ch){
				case 1:
					System.out.print("Enter client id: ");
					id = sc.nextInt();
					System.out.print("Enter client name: ");
					name = sc.next();
					System.out.print("Enter client address: ");
					addr = sc.next();
					System.out.print("Enter client hours: ");
					hours = sc.nextInt();
					hm.put(String.valueOf(id),new Client(name,id,addr,hours));
					break;
				case 2:
					System.out.print("Enter client id: ");
					id = sc.nextInt();
					Client c = hm.get(String.valueOf(id));
					if(c!=null){
						c.display();
					}else{
						System.out.println("The client must be added before an invoice can be created for the client.");
					}
					break;
				case 3: System.exit(0);
				default: System.out.println("Wrong choice entered.");
					break;
			}
		}
	}
}