Bank Customer CRUD API

A simple REST API for managing bank customer records.

This project was built with Spring Boot, Spring Data JPA, and H2 in-memory database. It supports basic CRUD operations for customer management.

Features

• Create a new customer
• Get all customers
• Get a customer by ID
• Update customer details
• Delete a customer
• Store customer records using H2 in-memory database

Tech Stack

• Java
• Spring Boot
• Spring Web
• Spring Data JPA
• H2 Database
• Maven

Project Structure

src
└── main
    ├── java
    │   └── com
    │       └── bank
    │           └── customer
    │               ├── CustomerApplication.java
    │               ├── controller
    │               │   └── CustomerController.java
    │               ├── entity
    │               │   └── Customer.java
    │               ├── repository
    │               │   └── CustomerRepository.java
    │               └── service
    │                   └── CustomerService.java
    └── resources
        └── application.properties

API Endpoints

Method	Endpoint	Description
POST	/api/customers	Create a new customer
GET	/api/customers	Get all customers
GET	/api/customers/{id}	Get a customer by ID
PUT	/api/customers/{id}	Update a customer
DELETE	/api/customers/{id}	Delete a customer

Customer Fields

{
  "id": 1,
  "firstName": "Marcus",
  "lastName": "Adigun",
  "email": "marcus@example.com",
  "phoneNumber": "08012345678"
}

Example Create Customer Request

POST /api/customers

{
  "firstName": "Marcus",
  "lastName": "Adigun",
  "email": "marcus@example.com",
  "phoneNumber": "08012345678"
}

Example Update Customer Request

PUT /api/customers/1

{
  "firstName": "Marcus",
  "lastName": "Updated",
  "email": "marcus.updated@example.com",
  "phoneNumber": "08111111111"
}

H2 Database Console

H2 console is available at:

http://localhost:8080/h2-console

Use this JDBC URL:

jdbc:h2:mem:bankdb

Default username:

sa

Leave the password empty.

How to Run the Project

Clone the repository:

git clone <your-repository-url>

Go into the project folder:

cd customer

Run the application:

./mvnw spring-boot:run

On Windows:

mvnw.cmd spring-boot:run

The application will start on:

http://localhost:8080

What I Practiced

This project helped me practice:

• Building REST APIs with Spring Boot
• Creating entities with JPA annotations
• Using Spring Data JPA repositories
• Structuring a project with controller, service, repository, and entity layers
• Testing API endpoints with Postman
• Using H2 as an in-memory database