Create a simple server that uses simple design patterns Factory Your server should parse the routes and create a new Processor class depending on the route Builder The process method of your Processor should use the Builder pattern to create a response DAO Make a class that abstracts the data interactions away from the rest of the app Singleton Wrap your dao instance as a singleton class Lazy Loading DAOs should only load data when requested DTO Your JSON parsing, as well as response objects must be DTOs First parse url, then use factory to instantiate correct Processor class The factory will internally use the builder pattern to give the processor relevant data Use builder to set the time, and input parameters Processor Class Has a process() method that returns a ResponseDto object Each endpoint is a subclass of Processor Takes a hashmap of key value args User a factory to create these, based on the endpoint Every processor uses a builder and returns the output of builder build() Response Class This class gets stringified with GSON Needs a ResponseBuilder helper Needs Params Map (String, String) Needs response dto Needs Response Code (String) UserDao class Singleton Lazy load data 1 DAO per type of endpoint to hold the data Endpoints Payment Methods addPaymentMethod method name creates a new payment method and stores it in the paymentMethod DAO assigns a machine code needs Payment DTO Payment DAO fields name, machineCode getAllPaymentMethods Returns list of all payment methods Items addItem name name price price Creates a new item and gives it a price Assigns machine readable code and returns it needs ItemDAO Item DTO fields name, price, machineCode listItems returns all items Transactions createTransaction itemCode code paymentMethod paymentCode Must have valid payment method fields itemCode, paymentMethod listTransactions returns all transaction needs TransactionDAO Transaction DTO

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Create a simple server that uses simple design patterns Factory: Your server should parse the routes and create a new Processor class depending on the

Create a simple server that uses simple design patterns

Factory: Your server should parse the routes and create a new Processor class depending on the route
Builder: The process method of your Processor should use the Builder pattern to create a response.
DAO: Make a class that abstracts the data interactions away from the rest of the app
Singleton: Wrap your dao instance as a singleton class
Lazy Loading: DAOs should only load data when requested
DTO: Your JSON parsing, as well as response objects must be DTOs

First parse url, then use factory to instantiate correct Processor class. The factory will internally use the builder pattern to give the processor relevant data. Use builder to set the time, and input parameters.

Processor Class

Has a process() method that returns a ResponseDto object
Each endpoint is a subclass of Processor
Takes a hashmap of key value args
User a factory to create these, based on the endpoint
Every processor uses a builder and returns the output of builder.build()

Response Class

This class gets stringified with GSON
Needs a ResponseBuilder helper
Needs Params Map (String, String)
Needs response dto
Needs Response Code (String)

UserDao class

Singleton
Lazy load data
1 DAO per type of endpoint to hold the data

Endpoints

Payment Methods
- /addPaymentMethod?method=name
  - creates a new payment method and stores it in the paymentMethod DAO
  - assigns a machine code
  - needs Payment DTO + Payment DAO
  - fields: name, machineCode
- /getAllPaymentMethods
  - Returns list of all payment methods
Items
- /addItem?name=name&price=price
  - Creates a new item and gives it a price
  - Assigns machine readable code and returns it
  - needs ItemDAO + Item DTO
  - fields: name, price, machineCode
- /listItems
  - returns all items
Transactions
- /createTransaction?itemCode=code&paymentMethod=paymentCode
  - Must have valid payment method
  - fields: itemCode, paymentMethod
- /listTransactions
  - returns all transaction
  - needs TransactionDAO + Transaction DTO