"I'm interested in Spring Boot, but it seems difficult."
"Where do I start when creating a business system?"
For those who have such concerns.
In this article,Java×Spring Boot business inventory management systemThe steps to build it from scratch are as follows:
Explanations that are easy to understand even for beginnersI will.
Including linking with MySQL and data storage processing,Basic methods that can be used on-siteYou can learn.
- What can you do with Spring Boot?
- Project configuration and preparation
- Database and Entity Design
- Implementing Data Operations: Repositories and Controllers
- Common errors and solutions
- Application functions and advanced examples
- Summary of the completed configuration
- Summary: You can create your own business systems
What can you do with Spring Boot?
Meet the requirements for a business system
Conclusion: Spring Boot allows you to create business applications efficiently and safely.
The business system needs the following:
- Registering, editing, and deleting data (CRUD function)
- Connecting to a database (e.g. MySQL)
- Stable routing structure
- Code reusability and maintainability
Spring Boot provides a mechanism to build these elements in a short time.
GovernmentInformation System Construction StandardsBut there is a need for a robust and maintainable design.
(Reference: Digital Agency https://www.digital.go.jp/policies/cloud-by-default/)
Project configuration and preparation
First, create a project with Spring Initializr.
Conclusion: Create a basic configuration on the official site and set up MySQL connection.
Preparation steps:
- Visit https://start.spring.io/
- Select the following settings:
- Project: Maven
- Language: Java
- Dependencies: Spring Web, Spring Data JPA, MySQL Driver
- After downloading, extract it in your favorite IDE (e.g. IntelliJ, VSCode)
next,application.propertiesSet it as follows:
1 | |
Database and Entity Design
Map a MySQL table to a Java class
Bottom line: Create Java classes to match your table structure.
Example: Product table "products"
1 | |
Entity class (Product.java)
1 | |
Implementing Data Operations: Repositories and Controllers
Allows you to list, register and delete product information
Conclusion: Using JPA functions, you can operate without writing SQL.
Repository interface (ProductRepository.java)
1 | |
Controller (ProductController.java)
1 | () () |
Common errors and solutions
Here are some common errors and how to fix them
- Error: Unknown database 'inventory_db'
→ Solution: Log in to MySQL,CREATE DATABASE inventory_db;Run - Error: Access denied for user 'root'@'localhost'
→ Solution:application.propertiesCheck that the password and user name are correct. - Error: Entity class not recognized
→ Solution:@EntityScanCheck annotations and correct package configuration
Application functions and advanced examples
Meet commercial-level requirements
Additional features can easily be implemented, such as:
- Update function (
PUTAdding a method - Input value check (
@Validand validation annotations) - Login function (Spring Security)
- Pagination support (
Pageableuse)
Summary of the completed configuration
1 | |
Example of operation check URL:
- GET http://localhost:8080/products
- POST http://localhost:8080/products
- DELETE http://localhost:8080/products/{id}
Summary: You can create your own business systems
In this article,MySQL-linked business system using Java and Spring BootI explained how to build it.
What I learned:
- Spring Boot project configuration and startup method
- Database operations with JPA
- Basic implementation of REST API
By further developing this technology, it will be possible to develop apps that can be used in practical applications.
please,Custom business systemTry building it!
English 
Japanese