Online-Ordering-Service

Backend for an online food ordering service made with Spring and DynamoDB

Author : Karan Chauhan

1. Introduction

A backend service has been implemented for an online food ordering service in Java with the Spring framework, using DynamoDB as the persisitance layer. DynamoDB local was used to test the code, and has to be running locally for testing. At server startup, it checks whether the tables required for computing, i.e., "Restaurant" and "Menu" exist or not in the local dynamo db of the tester; if they don't it creates them. I have implemented the persistance layer with two databases, Restaurant and Menu. The MenuItem table was ignored because I figured that a lot of db calls would have to be made for calls like DELETE /menu (all menuitem documents would have had to be deleted from the database) - an async delete could have been implemented, but has been omitted in the interest of time. Validations could be extracted out and handled using a custom Exception Class- ApiException and an ExceptionHandler. That has been left as a TODO.

2. Requirements

The server requires a DynamoDB server running locally for it to run, and also for building, since the unit test cases use the dynamoDb to validate the APIs. After downloading dynamoDbLocal, and unzipping it to a folder, we get a directory with, the following folders,

DynamoDBLocalLatest		hamcrest-core-1.3.jar
dynamodb_local_latest.zip	junit-4.12.jar

cd into the folder : DynamoDBLocalLatest and run the following command to start dynamoDBLocal server.

java -Djava.library.path=./DynamoDBLocal_lib -jar DynamoDBLocal.jar -sharedD

3. Directory Structure

.
main
├── java
│   └── com
│       └── zappos
│           └── onlineordering
│               ├── application
│               │   └── OnlineOrderingServiceApplication.java
│               ├── controller
│               │   └── RestaurantController.java
│               ├── model
│               │   ├── DeleteMenuItemRequest.java
│               │   ├── Menu.java
│               │   ├── MenuItem.java
│               │   ├── Restaurant.java
│               │   ├── RestaurantResponse.java
│               │   └── StatusResponse.java
│               ├── repository
│               │   ├── DynamoDBConfig.java
│               │   ├── MenuItemRepository.java
│               │   ├── MenuRepository.java
│               │   └── RestaurantRepository.java
│               ├── service
│               │   ├── RestaurantService.java
│               │   └── RestaurantServiceImpl.java
│               └── utils
│                   ├── Constants.java
│                   └── TableInit.java
└── resources
    └── application.properties

4. APIs

The project has implemented the following APIs for the food ordering service:

4.1 POST /addRestaurant

Using this API, a user can create a restaurant. He can choose to add list of menus now, or via the POST /menu

Request body

Field	Type	Description	Required
name	String	Name of the restaurant	Yes
address	String	List of values for the key	Yes
minOrder	Double	Minimum order for the restaurant	No
rating	Double	Rating of the restaurant	No

Sample input

POST http://127.0.0.1:8080/addRestaurant
{
    "name": "Raylene Continental House",
    "address": "New York",
    "minOrder": 20,
    "rating": 4.7
}

Sample output

 HttpStatus: 201 Created
{
    "id": "f41924cf-43a3-4525-a694-76a0435f5853",
    "name": "Raylene Continental House",
    "address": "New York",
    "minOrder": 20,
    "rating": 4.7
}

4.2 POST /addMenu

Using this API, a user can create a menu for a restaurant with passed restaurantId.

Request body

Field	Type	Description	Required
restaurantId	String	Id of the restaurant	Yes
mealType	String	Meal type of this meal	Yes
menuItems	List	List of menu Items. The menu item object is described below	No

MenuItem object

Field	Type	Description	Required
itemName	String	Name of menu item	Yes
itemPrice	String	Price of menu item	Yes
itemDescription	String	Description of menu item	No

#### Sample input
POST http://127.0.0.1:8080/addMenu/
{
    "restaurantId":"f41924cf-43a3-4525-a694-76a0435f5853",
    "mealType":"Dinner",
    "menuItems":[
        {
            "itemName":"Pepperoni Pizza",
            "itemPrice":"2",
            "itemDescription":"Made with the finest pork in town"
        },
        {
            "itemName":"Kolkata Rolls",
            "itemPrice":"3",
            "itemDescription":"One of the finest dishes straight from India"
        },
        {
            "itemName":"Mac and Cheese",
            "itemPrice":"4",
            "itemDescription":"Go back to the basics with this chef special"
        }
     ]
}

Sample output

 HttpStatus: 201 Created
{
    "menuId": "41b6f704-63e1-4815-8ae2-9eb015bc143b",
    "menuItems": [
        {
            "menuItemId": "202663b1-472f-4258-b7a7-83116c6bd4a2",
            "itemName": "Pepperoni Pizza",
            "itemPrice": "2",
            "itemDescription": "Made with the finest pork in town"
        },
        {
            "menuItemId": "46c25ed8-1360-4828-aa99-18417ce7eab2",
            "itemName": "Kolkata Rolls",
            "itemPrice": "3",
            "itemDescription": "One of the finest dishes straight from India"
        },
        {
            "menuItemId": "e6dfde0b-cc54-4200-b3ca-9e0eefe25a09",
            "itemName": "Mac and Cheese",
            "itemPrice": "4",
            "itemDescription": "Go back to the basics with this chef special"
        }
    ],
    "restaurantId": "f41924cf-43a3-4525-a694-76a0435f5853",
    "mealType": "DINNER"
}

4.3 GET /restaurant/{id}?type=

This API returns a complete view of the restaurant with all its menus. If the query parameter, 'type' is set, then it will return a menu of that mealType only.

Sample input

GET http://127.0.0.1:8080/restaurant/f41924cf-43a3-4525-a694-76a0435f5853?type=dinner

Sample output

HttpStatus: 200 OK
{
    "id": "f41924cf-43a3-4525-a694-76a0435f5853",
    "name": "Raylene Continental House",
    "address": "New York",
    "minOrder": 20,
    "rating": 4.7,
    "menu": [
        {
            "menuId": "41b6f704-63e1-4815-8ae2-9eb015bc143b",
            "menuItems": [
                {
                    "menuItemId": "202663b1-472f-4258-b7a7-83116c6bd4a2",
                    "itemName": "Pepperoni Pizza",
		    "itemPrice": "2",
		    "itemDescription": "Made with the finest pork in town"
                },
                {
                    "menuItemId": "46c25ed8-1360-4828-aa99-18417ce7eab2",
                    "itemName": "Kolkata Rolls",
                    "itemPrice": "3",
                    "itemDescription": "One of the finest dishes straight from India"
                },
                {
                    "menuItemId": "e6dfde0b-cc54-4200-b3ca-9e0eefe25a09",
                    "itemName": "Mac and Cheese",
                    "itemPrice": "4",
                    "itemDescription": "Go back to the basics with this chef special"
                }
            ],
            "restaurantId": "f41924cf-43a3-4525-a694-76a0435f5853",
            "mealType": "DINNER"
        }
    ]
}

4.4 POST /menu/{id}/item

This API adds a menu item to an existing menu with menuId as the one in the path parameter. Returns the complete updated menu.

Request body

Field	Type	Description	Required
itemName	String	Name of menu item	Yes
itemPrice	String	Price of menu item	Yes
itemDescription	String	Description of menu item	No

Sample input

HttpStatus: 201 Created
POST http://127.0.0.1:8080/menu/41b6f704-63e1-4815-8ae2-9eb015bc143b/item
{
            "itemName": "The Baconator",
            "itemPrice": "7.5",
            "itemDescription": "One of this week's specials"
}

Sample output

{
    "menuId": "41b6f704-63e1-4815-8ae2-9eb015bc143b",
    "menuItems": [
        {
            "menuItemId": "202663b1-472f-4258-b7a7-83116c6bd4a2",
            "itemName": "Pepperoni Pizza",
            "itemPrice": "2",
            "itemDescription": "Made with the finest pork in town"
        },
        {
            "menuItemId": "46c25ed8-1360-4828-aa99-18417ce7eab2",
            "itemName": "Kolkata Rolls",
            "itemPrice": "3",
            "itemDescription": "One of the finest dishes straight from India"
        },
        {
            "menuItemId": "e6dfde0b-cc54-4200-b3ca-9e0eefe25a09",
            "itemName": "Mac and Cheese",
            "itemPrice": "4",
            "itemDescription": "Go back to the basics with this chef special"
        },
        {
            "menuItemId": "51eb721f-e0ac-424c-b934-7995c635ab3d",
            "itemName": "The Baconator",
            "itemPrice": "7.5",
            "itemDescription": "One of this week's specials"
        }
    ],
    "restaurantId": "f41924cf-43a3-4525-a694-76a0435f5853",
    "mealType": "DINNER"
}

4.5 DELETE /menu/item

This API deletes a menu item from a menu.

Request body

Field	Type	Description	Required
menuId	String	Id of menu	Yes
menuItemId	String	Id of menu item	Yes

Sample input

DELETE http://127.0.0.1:8080/menu/item
{
	"menuId":"e8dfc246-ef55-4b29-a20c-f3e74dd3391f",
	"menuItemId":"81fbce19-53ba-4c7c-8e4f-82ff1d989dd6"
}

Sample output

HttpStatus: 200 OK
{
    "status": "0",
    "message": "Menu Item deleted successfully"
}

4.6 DELETE /menu/{id}

This API deletes a menu for a restaurant. Updates mealType map for restaurant.

Sample input

DELETE http://127.0.0.1:8080/menu/41b6f704-63e1-4815-8ae2-9eb015bc143b
{
	"menuId":"e8dfc246-ef55-4b29-a20c-f3e74dd3391f",
	"menuItemId":"81fbce19-53ba-4c7c-8e4f-82ff1d989dd6"
}

Sample output

HttpStatus: 200 OK
{
    "status": "0",
    "message": "Menu deleted successfully"
}

4.7 DELETE /restaurant/{id}

This API deletes a restaurant and all its linked menus.

Sample input

DELETE http://127.0.0.1:8080/restaurant/f41924cf-43a3-4525-a694-76a0435f5853

Sample output

HttpStatus: 200 OK
{
    "status": "0",
    "message": "Restaurant deleted successfully"
}