COMP249-Assignment 1 Appliance Creator Solved

Part I)  
An appliance object has four attributes, a type (String), a brand (String), a serial number (long), and a price (double). The type of an appliance can be any of the following: Fridge, Air Conditioner, Washer, Dryer, Freezer, Stove, Dishwasher, Water Heaters, and Microwave. The brand indicates the vendor/manufacturer of the appliance (such as LG, Samsung, Bosch, etc.), and can be any string. The serial number represents the serial number of the appliance, and must be unique. For simplicity, we assume that the serial numbers start at 1000000 and it is common/shared among all different brands and types (for example, if the creation of objects starts by a Washer created by Maytag, then it will be assigned serial number 1000000. If a Microwave by Breville is created next, then it will be assigned serial number 1000001, and so on afterwards). The price of an appliance cannot be less than 1$.  (Hint: Static – You are allowed to add other attributes to the class.) 

For this part, you are required to design and implement the Appliance class according to the following specifications:  

 

-        Upon the creation of an appliance object, the object must immediately be initialized with valid values; that is type, brand, serial number and price. (Hint: Constructors.) 

 

-        The design should allow enough flexibility so that the value of any of these attributes can be modified later on (with the exception of the serial number, which can never be changed once assigned). For example, it should be possible to create an appliance object with a given price then change its price later on.  Notice that changes to brand or type is allowed (although this is unusual in reality!). The design should also allow the user to obtain the value of any of the attributes. (Hint: Accessors & Mutators.)  

-        The design should allow all information of an object to be displayed at once through the utilization of System.out.print() method. (Hint: toString() method) 

 

-        It is required to know how many appliance objects have been created. For that, you need to add a method, called findNumberOfCreatedAppliances(), to the class. This method must return the number of created appliance objects prior to the time this method is called. The method would simply return 0 if no appliances have been created by the time the method is called.  

 

-        It is required to compare two Appliance objects for equality. Two appliances are considered equal if they have the same brand, type and price. (Hint: equals() method) 

 

-        It is required to display any Appliance object (all info of that object) using System.out.println() method. (Hint: toSting() method) 

 

 

 

Part II)  
You are hired by a major appliance dealer to write a software that helps the store owner in acquiring and keeping track of appliances at the store. Write a driver program that will contain, at least, the following methods. Note: You can have the main function in a separate driver file, or in the same file if you prefer.

 

1. a main() method, that will:

a.      Display a welcome message;

b.      Prompt the store owner for the maximum number of appliances (maxAppliances) his/her store can contain (or wish to aquire; this is not a focus here). Create an empty array, called inventory, that will have the potential of keeping track of the created Appliance objects.

c.      Display a main menu (Figure 1) with the following choices and keep prompting the user until they enter a number between 1 and 5 inclusive (i.e invalid number will result in repeating the display of the main menu):  

 

What do you want to do? 

1.      Enter new appliances (password required) 

2.      Change information of an appliance (password required) 

3.      Display all appliances by a specific brand 4. Display all appliances under a certain a price. 

5. Quit 

Please enter your choice  
 

 

 

 

 Figure 1. Main  menu 

 

d.      When option 1 is entered:

i.       Prompt the store owner for his/her password. (Make sure you have a constant variable containing the password “c249” – do not use any other password as it will be easier for the marker to check your assignments). The store owner has a maximum of 3 attempts to enter the correct password. After the 3rd illegal entry, the main menu in Figure 1 is redisplayed again. Additionally after this process is repeated 4 consecutive times (i.e. total failed attempts is 12 consecutive attempts by now), the program must display the following messages: “Program detected suspicious activities and will terminate immediately!”, then the program must exits.  

 

ii.     If the correct password is entered (which will reset the counter of failed attempts), ask the owner how many appliances he/she wants to enter. Check that there is enough space in the store (inventory array) to add these many appliances. If so, add them; otherwise inform the owner of the maximum remaining places in the array. (How the appliance information is input/entered by the user is up to you).  

 

e.      When option 2 is entered:

i.       Prompt the store owner for his/her password. (Still, you should make sure the password is “c249” – do not use another password). Again the store owner has 3 attempts to enter the correct password. However, after the 3rd illegal entry, the main menu in Figure 1 is simply re-displayed again (notice the different behaviour in that case from the previous one above).

 

ii.     Ask the user of the serial number of the appliance he/she wishes to update. If there is no object with that serial number in the array inventory, display a message indicating that and ask the user if he/she wishes to re-enter another serial number, or quit this operation and go back to the main menu. If the entered serial number exists, display the current information of that appliance in the following format:

 

Appliance Serial # xxxxxxx (where xxxxxxx is the serial number)    Brand: brand of the appliance 

                                                        Type: type of the appliance  

                                                        Price: price 

 

Then ask the user which attribute he/she wishes to change by displaying the following menu.  

What information would you like to change? 

1.      brand 

2.      type 

3.      price 

4.      Quit 

Enter your choice  
 

 

 

 Figure 2. Update  menu 

 

  

 

 

Once the user has entered a correct choice, ask the user for the new information and make the changes to the object attribute then display again all of the attributes on the screen to show that the change has taken place. Keep prompting the user for additional changes until the user enters 4 (indicating that he/she wishs to stop the update process). Each time the user is prompted for a choice, make sure that a number from 1 to 4 is entered, otherwise keep prompting until a valid number is entered. You should pay a special attention to the change when it comes to type, as the different types are specific and limited (cannot be different than the types indicated in the initial description in Part I above).  

  

f.      When option 3 (in the main menu shown in Fig. 1) is entered, prompt the user to enter a brand name. You then need to display the information of all appliances in the inventory with that brand. (Hint: You may use a static method, for instance called findAppliancesBy, which accepts a string for an brand name then performs the needed search).  

 

g.     When option 4 (in the main menu shown in Figure 1) is entered, prompt the user to enter a value (representing a price). You then need to display all appliances in the store that have a price smaller than that entered value.  (Hint: You may use a static method, for instance called findCheaperThan, which accepts a double value, for a price, then performs the needed search).  

 

h.     When option 5 (in the main menu shown in Fig. 1) is entered, display a closing message and end the program.