Fun Exercise: Developing a Financial Technology Application

This project involves building a financial technology application based on a predefined API specification.

Prerequisites

Before starting, ensure you have the following tools and resources

• Java: Java 17
• IDE: IntelliJ IDEA (or any IDE compatible with Spring Boot applications)

Getting Started

1. Clone the Repository: Use Git to clone the project repository to your local machine.
2. Import the Project: Import the project and make sure all dependencies are correctly resolved.
3. Run the Application: Ensure that all prerequisites are correctly configured. Click me to verify
4. Login H2 Console: Connect and verify schema and data are correctly initialized (resources/data.sql, resources/scheme.sql) H2 Console.
   • Driver Class: org.h2.Driver
   • JDBC URL: jdbc:h2:mem:testdb
   • User Name: sa
   • Password:
   • 
   • 
5. Looking at the AccountController: You can see that the controller has the following endpoints:
   • GET /accounts: Retrieves an accounts.
   • POST /accounts/{accountNo}/deposit: Deposits an amount to the account.
6. Testing an API with Swagger UI: You can test the endpoints using the Swagger UI at http://localhost:8080/swagger-ui.html.
   • POST /accounts/{accountNo}/deposit: deposits an amount to the account.
     • 
   • Make a change to AccountController.java: Go to line: 37 @Operation(summary = "withdraw from an account")
     • Change the value of summary to deposits an amount to the account.
     • Rerun the application, and then we'll see result of that change.
   • 🎨 Try to make any change and learn what happens.

Instructions

Your task is to develop a financial technology application in line with the provided API specification, which includes the following endpoints:

• GET /accounts: Retrieves an accounts. (We have already implemented this endpoint ✅)
• POST /accounts/{accountNo}/deposit: Deposits an amount to the account. (We have already implemented this endpoint ✅)
• POST /accounts: Creates an account. Challenge 1
• POST /accounts/{accountNo}/withdraw: Withdraws an amount from the account. Challenge 2
• POST /accounts/{accountNo}/transfer/{targetAccountNo}: Transfers an amount from one account to another. Challenge 3
• GET /accounts/{accountNo}: Retrieves an account. Challenge 4

In the case of various errors, the system should respond with appropriate status codes, such as:

• 400 Bad Request for client-side errors.
• 500 Internal Server Error for server-side errors.

Challenge 1: Create POST: /accounts endpoint according to the API specification

Suggestion: Open API specification and try to understand the request and response body. Then, implement the endpoint.

Hint: Challenge 1

HTTP Method: POST
Request Mapping: /accounts

Request Body: 
{
  "type": "SAVING",
  "name": "string",
  "balance": 0 <- Double
}


Response:
{
  "no": 0, <- Integer
  "type": "SAVING",
  "name": "string",
  "balance": 0 <- Double
}

Using @Operation annotation to add description to the endpoint.

@Operation(summary = "จนมาเห็นกับตา จนพาใจมาเจ็บ")

Using @ApiResponses annotation to add response code and description to the endpoint.

@ApiResponses({
   @ApiResponse(responseCode = "200", description = "ฉีกบ่มีหม่องเย็บ หัวใจที่ให้เจ้า", { ... })
})

Challenge 2: Create POST /accounts/{accountNo}/withdraw endpoint according to the API specification

Suggestion: Open API specification and try to understand the request and response body. Then, implement the endpoint.

Hint: Challenge 2

HTTP Method: POST
Request Mapping: /accounts/{accountNo}/withdraw
Path Variable: accountNo (Integer)
Request Body: 
{
  "amount": 0 <- Double
}

Response
{
  "no": 0, <- Integer
  "type": "SAVING",
  "name": "string",
  "balance": 0 <- Double
}

• Using @PathVariable annotation to get the value of the path variable.
• Using @RequestBody annotation to get the value of the request body.
• Using @Operation annotation to add description to the endpoint.

  @Operation(summary = "บักคนซั่วจั่งอ้าย มันเอาเหล้ายาปลาปิ้งเป็นใหญ่")
  

• Using @ApiResponses annotation to add response code and description to the endpoint.

  @ApiResponses({
     @ApiResponse(responseCode = "200", description = "มันบ่เหมาะกับไผไคแนแต่ไปเลาะหาเซ็นเหล้า", { ... })
  })
  

Challenge 3: Create POST /accounts/{accountNo}/transfer/{targetAccountNo} endpoint according to the API specification

Suggestion: Open API specification and try to understand the request and response body. Then, implement the endpoint.

Hint: Challenge 3

HTTP Method: POST
Request Mapping: /accounts/{accountNo}/transfer/{targetAccountNo}
Path Variable: accountNo (Integer), targetAccountNo (Integer)
Request Body: 
{
  "amount": 0, <- Double
  "remark": "string"
}

Response (My account)
{
  "no": 0,
  "type": "SAVING",
  "name": "string",
  "balance": 0 <- Double
}

Using @Operation annotation to add description to the endpoint.

@Operation(summary = "แม่ฮ้างมหาเสน่ห์")

Using @ApiResponses annotation to add response code and description to the endpoint.

@ApiResponses({
   @ApiResponse(responseCode = "200", description = "...", { ... })
})

Challenge 4: Create GET /accounts/{accountNo} endpoint according to the API specification

Suggestion: Open API specification and try to understand the request and response body. Then, implement the endpoint.

Hint: Challenge 4

HTTP Method: GET
Request Mapping: /accounts/{accountNo}
Path Variable: accountNo (Integer)

Response
{
  "no": 0, <- Integer
  "type": "SAVING",
  "name": "string",
  "balance": 0 <- Double
}

Using @Operation annotation to add description to the endpoint.

@Operation(summary = "My sugar daddy, หมดใจเลยที่ฟ้าให้พ่อ")

Using @ApiResponses annotation to add response code and description to the endpoint.

@ApiResponses({
   @ApiResponse(responseCode = "200", description = "รักจริงไม่ได้หลอก แค่อยากจะขอให้พ่อช่วยฟ้าหน่อย", { ... })
})