Banking Application with Spring Boot, Spring Data JPA, and MySQL

Overview

• Build a simple banking application.
• Use the latest versions of Spring Boot, Spring Data JPA, and MySQL.

Setup

1. Start Spring Initializer: Go to start.spring.io.
   • Project: Maven
   • Language: Java
   • Spring Boot Version: 3.2.1 (latest stable)
2. Project Metadata:
   • Group: net.javaguides
   • Artifact: banking-app
   • Description: Demo project for Spring Boot banking app
   • Package Name: net.java.banking
   • Packaging: jar
   • Java Version: 17
3. Dependencies:
   • Spring Web: For building REST APIs.
   • Spring Data JPA: For JPA repositories and hibernate.
   • MySQL Driver: For connecting Spring Boot with MySQL.
   • Lombok: To reduce boilerplate code.
4. Generate: Download the .zip file and unzip it.
5. Open in IDE: Import the project in IntelliJ IDEA.

Configuration

1. MySQL Database:
   • Create the database using MySQL Workbench.
   • SQL Statement: CREATE DATABASE banking_app;
2. Spring Boot Application:
   • Go to src/main/resources/application.properties.
   • Configure MySQL Database details: spring.datasource.url=jdbc:mysql://localhost:3306/banking_app spring.datasource.username=root spring.datasource.password=password spring.jpa.hibernate.ddl-auto=update
3. Run Application: Ensure connectivity with database.

Project Structure

• Packages:
  • entity: For JPA entities
  • controller: For REST controllers
  • service: For service layer
  • repository: For Spring Data JPA repositories
  • dto: For data transfer objects
  • mapper: For converting DTOs to entities and vice versa

Implementation

1. Entity: Account
   • Fields: id, accountHolderName, balance
   • Annotations: @Entity, @Table(name="accounts"), @Id, @GeneratedValue(strategy = GenerationType.IDENTITY), @Column(name="account_holder_name")
2. DTO: AccountDto
   • Fields: id, accountHolderName, balance
   • Lombok Annotations: @Data, @AllArgsConstructor, @NoArgsConstructor
3. Mapper: AccountMapper
   • Methods: mapToAccount(AccountDto accountDto), mapToAccountDto(Account account)
4. Repository: AccountRepository
   • Interface extending JpaRepository<Account, Long>
5. Service: AccountService
   • Interface: createAccount(AccountDto accountDto), getAccountById(Long id), getAllAccounts(), deposit(Long id, Double amount), withdraw(Long id, Double amount), deleteAccount(Long id)
   • Implementation: AccountServiceImpl
6. Controller: AccountController
   • REST Endpoints:
     • createAccount(AccountDto accountDto)
     • getAccountById(@PathVariable Long id)
     • getAllAccounts()
     • deposit(@PathVariable Long id, @RequestBody Map<String, Double> request)
     • withdraw(@PathVariable Long id, @RequestBody Map<String, Double> request)
     • deleteAccount(@PathVariable Long id)

REST API Testing

1. Add Account:
   • URL: http://localhost:8080/api/accounts
   • Method: POST
   • Request Body: { "accountHolderName": "John Doe", "balance": 20000 }
   • Response: { "id": 1, "accountHolderName": "John Doe", "balance": 20000 }
2. Get Account by ID:
   • URL: http://localhost:8080/api/accounts/{id}
   • Method: GET
   • Response: { "id": 1, "accountHolderName": "John Doe", "balance": 20000 }
3. Get All Accounts:
   • URL: http://localhost:8080/api/accounts
   • Method: GET
   • Response: [{ "id": 1, "accountHolderName": "John Doe", "balance": 20000 }, { "id": 2, "accountHolderName": "Jane Doe", "balance": 15000 }]
4. Deposit:
   • URL: http://localhost:8080/api/accounts/{id}/deposit
   • Method: PUT
   • Request Body: { "amount": 5000 }
   • Response: { "id": 1, "accountHolderName": "John Doe", "balance": 25000 }
5. Withdraw:
   • URL: http://localhost:8080/api/accounts/{id}/withdraw
   • Method: PUT
   • Request Body: { "amount": 5000 }
   • Response: { "id": 1, "accountHolderName": "John Doe", "balance": 20000 }
6. Delete Account:
   • URL: http://localhost:8080/api/accounts/{id}
   • Method: DELETE
   • Response: Account is deleted successfully

Postman Testing

1. Add Account: Tested using Postman Client.
2. Get Account by ID: Verified using Postman and database.
3. Get All Accounts: Verified using Postman and database.
4. Deposit: Confirmed balance update via Postman and database.
5. Withdraw: Ensured proper deduction via Postman and database.
6. Delete Account: Verified account removal using Postman and database.