Restaurant management software In Java.

 an example of a simplified restaurant management software implemented in Java. This software allows you to manage menu items, track orders, and calculate bills. Please note that this is a basic implementation and can be expanded upon according to your specific requirements.

```java

import java.util.ArrayList;

import java.util.List;

import java.util.Scanner;

class MenuItem {

    private String name;

    private double price;

    public MenuItem(String name, double price) {

        this.name = name;

        this.price = price;

    }

    public String getName() {

        return name;

    }

    public double getPrice() {

        return price;

    }

}

class Order {

    private MenuItem item;

    private int quantity;

    public Order(MenuItem item, int quantity) {

        this.item = item;

        this.quantity = quantity;

    }

    public MenuItem getItem() {

        return item;

    }

    public int getQuantity() {

        return quantity;

    }

    public double getTotalPrice() {

        return item.getPrice() * quantity;

    }

}

class Restaurant {

    private List<MenuItem> menu;

    private List<Order> orders;

    public Restaurant() {

        menu = new ArrayList<>();

        orders = new ArrayList<>();

    }

    public void addMenuItem(MenuItem item) {

        menu.add(item);

    }

    public void displayMenu() {

        System.out.println("Menu:");

        for (int i = 0; i < menu.size(); i++) {

            MenuItem item = menu.get(i);

            System.out.println((i + 1) + ". " + item.getName() + " - $" + item.getPrice());

        }

        System.out.println();

    }

    public void placeOrder(MenuItem item, int quantity) {

        Order order = new Order(item, quantity);

        orders.add(order);

    }

    public void displayOrders() {

        System.out.println("Orders:");

        for (int i = 0; i < orders.size(); i++) {

            Order order = orders.get(i);

            System.out.println((i + 1) + ". " + order.getItem().getName() + " - Quantity: " + order.getQuantity() +

                    " - Total Price: $" + order.getTotalPrice());

        }

        System.out.println();

    }

    public double calculateTotalRevenue() {

        double totalRevenue = 0;

        for (Order order : orders) {

            totalRevenue += order.getTotalPrice();

        }

        return totalRevenue;

    }

}

public class RestaurantManagementSoftware {

    public static void main(String[] args) {

        Restaurant restaurant = new Restaurant();

        Scanner scanner = new Scanner(System.in);

        MenuItem item1 = new MenuItem("Burger", 9.99);

        MenuItem item2 = new MenuItem("Pizza", 12.99);

        MenuItem item3 = new MenuItem("Salad", 6.99);

        restaurant.addMenuItem(item1);

        restaurant.addMenuItem(item2);

        restaurant.addMenuItem(item3);

        boolean exit = false;

        while (!exit) {

            System.out.println("1. Display Menu");

            System.out.println("2. Place Order");

            System.out.println("3. Display Orders");

            System.out.println("4. Calculate Total Revenue");

            System.out.println("5. Exit");

            System.out.print("Enter your choice: ");

            int choice = scanner.nextInt();

            switch (choice) {

                case 1:

                    restaurant.displayMenu();

                    break;

                case 2:

                    restaurant.displayMenu();

                    System.out.print("Enter item number: ");

                    int itemNumber = scanner.nextInt();

                    System.out.print("Enter quantity: ");

                    int quantity = scanner.nextInt();

                    MenuItem selectedItem = restaurant.getMenu().get(itemNumber - 1);

                    restaurant.placeOrder(selectedItem, quantity);