LIVE Instructor-Led Courses
Dismiss
Building Microservices REST API with Spring Boot: A Comprehensive Guide

6 April 2023

Building Microservices REST API using Spring Boot

Introduction:

Microservices have become the go-to architecture for developing large-scale applications in recent years. They provide scalability, flexibility, and maintainability, making it easier to develop and deploy complex applications. Spring Boot, with its built-in support for microservices, has become one of the most popular frameworks for building microservices-based applications. In this article, we'll take a deep dive into building microservices REST API using Spring Boot.

Step-by-Step Guide:

Step 1: Set up a Spring Boot project To start building a Spring Boot microservices REST API, you first need to set up a new Spring Boot project. You can do this by using the Spring Initializr or by manually creating a new project in your favorite IDE.

Step 2: Add dependencies After setting up the Spring Boot project, you need to add the necessary dependencies. To build a microservices-based REST API, you'll need to add the Spring Web and Spring Data JPA dependencies. You can do this by adding the following lines to your pom.xml file:


 

<dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-jpa</artifactId> </dependency> </dependencies>

Step 3: Create a REST API controller Now that you have set up your project and added the necessary dependencies, you can start creating your REST API controller. To do this, create a new Java class and annotate it with the @RestController annotation. This annotation tells Spring that this class is a REST controller and that all its methods return REST responses. Here's an example:


 

@RestController @RequestMapping("/api") public class UserController { @Autowired private UserRepository userRepository; @GetMapping("/users") public List<User> getAllUsers() { return userRepository.findAll(); } @PostMapping("/users") public User createUser(@RequestBody User user) { return userRepository.save(user); } @GetMapping("/users/{id}") public User getUserById(@PathVariable Long id) { return userRepository.findById(id).orElseThrow(() -> new ResourceNotFoundException("User not found")); } @PutMapping("/users/{id}") public User updateUser(@PathVariable Long id, @RequestBody User userDetails) { User user = userRepository.findById(id).orElseThrow(() -> new ResourceNotFoundException("User not found")); user.setName(userDetails.getName()); user.setEmail(userDetails.getEmail()); user.setPhone(userDetails.getPhone()); User updatedUser = userRepository.save(user); return updatedUser; } @DeleteMapping("/users/{id}") public ResponseEntity<?> deleteUser(@PathVariable Long id) { User user = userRepository.findById(id).orElseThrow(() -> new ResourceNotFoundException("User not found")); userRepository.delete(user); return ResponseEntity.ok().build(); } }

In this example, we have created a UserController class that has various REST endpoints such as getAllUsers, createUser, getUserById, updateUser, and deleteUser. We have also used the Spring Data JPA repository to interact with the database.

Step 4: Set up the application properties You now need to set up the application properties. In the application.properties file, add the following lines:


 

spring.jpa.hibernate.ddl-auto=update spring.datasource.url=jdbc:mysql://localhost:3306/mydatabase spring.datasource.username=root spring.datasource.password=password

These lines configure the database that the application will use. In this example, we're using MySQL as the database.

Step 5: Create a data model Next, create a data model that maps to your database table. For example, if you have a users table in your database, you can create a User class that maps to that table. Here's an example:

@Entity @Table(name = "users") public class User { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) private Long id; @Column(name = "name") private String name; @Column(name = "email") private String email; @Column(name = "phone") private String phone; // getters and setters }

In this example, we have annotated the User class with the @Entity annotation to indicate that it is a JPA entity. We have also specified the table name using the @Table annotation, and we have used the @Id and @GeneratedValue annotations to specify the primary key field.

Step 6: Create a repository After creating the data model, you need to create a repository interface that extends the Spring Data JPA CrudRepository interface. Here's an example:

public interface UserRepository extends CrudRepository<User, Long> { }

This repository interface provides basic CRUD operations for the User entity.

Step 7: Run the application You have now completed all the necessary steps to build a microservices REST API using Spring Boot. You can run the application using your IDE or by running the mvn spring-boot:run command in the terminal.

Use Cases:

  1. Building a REST API for an e-commerce application to manage products and orders
  2. Building a REST API for a social media application to manage user profiles and posts
  3. Building a REST API for a finance application to manage transactions and customer accounts

Conclusion: In this article, we have covered the step-by-step process of building a microservices REST API using Spring Boot. We started by setting up a new Spring Boot project, adding the necessary dependencies, creating a REST API controller, setting up the application properties, creating a data model, creating a repository, and finally running the application. We also provided some use cases for building a microservices-based REST API using Spring Boot. By following the steps outlined in this article, you can easily build a robust and scalable microservices-based REST API using Spring Boot.

Official Documentation: You can find more information about building microservices using Spring Boot in the official Spring Boot documentation: https://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#boot-features-restful-services

You can also find more information about building RESTful web services with Spring in the official Spring documentation: https://docs.spring.io/spring-framework/docs/current/reference/html/web.html#spring-we

JBI Training offers a number of courses. Some of our most popular courses are found below. We can customize a course for your teams needs, for any training requirements or requests simply get in touch. 

 

About the author: Daniel West
Tech Blogger & Researcher for JBI Training

CONTACT
+44 (0)20 8446 7555

[email protected]

SHARE

 

Copyright © 2023 JBI Training. All Rights Reserved.
JB International Training Ltd  -  Company Registration Number: 08458005
Registered Address: Wohl Enterprise Hub, 2B Redbourne Avenue, London, N3 2BS

Modern Slavery Statement & Corporate Policies | Terms & Conditions | Contact Us

POPULAR

Rust training course                                                                          React training course

Threat modelling training course   Python for data analysts training course

Power BI training course                                   Machine Learning training course

Spring Boot Microservices training course              Terraform training course

Kubernetes training course                                                            C++ training course

Power Automate training course                               Clean Code training course