Checklist for SKE Restaurant Assignment

This is a list of common issues seen in the SKE Restaurant code. Please check your project.

Github Checks

  1. Repository is named ske-restaurant exactly. Not “ske restaurant” or “ske-restaurant.” (no period) or “SKE-restaurant” (wrong case).
  2. Repository has correct directory structure. 
     README.md
 .gitignore
 src/       (source code)
 src/data   (menu data file)

Checklist for RestaurantManager

  1. All attributes are private. The other classes should not directly access attributes.
  2. Has the methods required in Homework 3:
Method Description
public static String[] getMenuItems() Return array of menu item names.
public static double[] getPrices() Return array of menu item prices.
public static void recordOrder(int orderNumber, int[] order, double total) Record a completed order. Your method may be different or have different parameters. But the order should be a parameter.
  1. RestaurantManager does not interact with customer.
  2. RestaurantManager does not have an attribute for an order. recordOrder receives order as a parameter. There is no need for an attribute for this.
  3. Write a good Javadoc comment. That should be obvious by now.
import java.util.List;
import java.noway.DontCopyThis;

/**
 * The Restaurant Manager provides services of the
 * restaurant, including access to the menu and prices,
 * and receiving orders. It records orders to a file.
 *
 * @author Bill Gates
 */
public class RestaurantManager {
    private String[] menuItems;
    private double[] prices;
    // no ArrayList attributes. they are local variables used temporarily.

Checklist for Restaurant (or whatever class accepts order from user)

  1. Gets the menuItems and prices from RestaurantManager one time and saves them. 
    public class Restaurant {

 private String[] menuItems = RestaurantManager.getMenuItems();
 private double[] prices = RestaurantManager.getPrices();

 /** This is an example of flow of accepting/submitting an order. 
     Your code will probably be different.
  */
 public void makeOrder() {
      int[] order = new int[menuItems.length];
      while( ! complete ) {
          getitems( order ); // accept item using a loop
          displayTotal( order );
          complete = confirmOrder( order );
      }
      double totalPrice = getTotal(order);
      long orderNumber = RestaurantManger.recordOrder( order, totalPrice );
      printReceipt( order, orderNumber, totalPrice );
 }
  2. Don’t repeatedly nag RestaurantManager for the menu. Don’t do this: 
    for(int k=0; k<RestaurantManger.getMenuItems().length; k++) {
  System.out.printf("[%2d] %-30.30s  %.2f\n",
   k+1, RestaurantManager.getMenuItems()[k], RestaurantManager.getPrices()[k]);
}
  3. Even worse, don’t directly access attributes of RestaurantManager. The attributes should be private. 
    // Totally wrong: directly access attribute of another class
for(int k=0; k<RestaurantManger.menuItems.length; k++) {
  System.out.printf("[%2d] %-30.30s  %.2f\n",
   k+1, RestaurantManager.menuItems[k], RestaurantManager.prices[k] );
}
  4. Create a new order array (or order object) for each order. You pass the order as parameter to methods instead of using an attribute for order.
    • This isn’t as important as the above checklist items. Its not good design to use an attribute for order, but not terrible.

Checklist from Homework 2 (some items removed)

  1. Project on Github is named ske-restaurant
    • in the repository, source code is in the src directory.
  2. Project has a README.md describing the project.
    • includes your real name
    • correctly formatted with Markdown. If it looks like crap (bad formatting), it means you didn’t bother to check your own repo on Github!

  3. Source code contains a class Javadoc comment, which must be after the import statements and before the start of class.

     // don't copy this!  its just example to show where to write Javadoc
 import java.util.Scanner;
 import java.util.Arrays;
 /**
  * Main class for SKE Restaurarnt order taking application.
  * It displays a menu and accepts items to order.
  * When done, it prints a receipt including the order total.
  *
  * @author Bill Gates
  */
 public class Restaurant
  4. For really good code, write Javadoc method comments for important methods. See the Arrays lab for examples.
  5. The array for the customer’s order is a local variable, not an attribute.
    • This avoids lots of subtle bugs, avoids side effects, and reduces complexity of the code.
    • It makes it easier to test each method of the code.
    • Each time you start a new order, either create a new array or reset (“fill”) existing array with 0.
      GOOD (order is local variable, pass it to methods as parameter) 
       public void makeOrder() {
  int[] order = new int[menuItems.length];
  ...

      BAD (order is attribute)

       public class Restaurant {
  private static int[] order;
  6. Don’t “hard code” the menu items or prices in code.
    GOOD 
     public static void printMenu() {
     ...
     System.out.printf("%-20.20s  %.2f%n", menuItems[k], unitPrice[k]);

    BAD

     public static void printMenu() {
     ...
     System.out.printf("Tofu          20.0 Baht%n"); // hard-coding data into code
  7. Use methods for tasks. For example, computing the total price of order:
    GOOD (a separate method to compute the total, as needed) 
    public static double getTotal(int[] order) {
     double total = 0.0;
     for(int k=0; k<order.length; k++) total += order[k]*unitPrice[k];
     // do other stuff, like add VAT or apply a discount
     return total;
 }

    BAD (incrementally computing total as a side-effect)

     // This method is both adding something to the order
 // AND computing the order total.  This is error-prone.
 // Remember: 1) method should do only one thing, 2) minimize side effects
 public static void addToOrder(int item, int quantity) {
     order[item] += quantity;
     total = total + quantity * unitPrice[item]; // BAD: modifying total as a side-effect
 }
  8. Test Your Code.
    • Don’t test inside the IDE, because you may miss some bugs.
    • Use a command prompt and change to the project “bin” (Eclipse) or “build” (Netbeans) or “out/production” (IntelliJ) directory. Then run: 
       cmd>  cd ske-restaraurant/bin
 cmd>  java MyMainClass
    • If your code is in a package, use “.” (not /) after package name(s). 
       cmd>  java restaurant.MyMainClass
    • Even better: get a friend to test your code! They will find bugs you don’t see.