Microservices Using Spring Boot Tutorial for Beginners | Simple Guide for Students

 

If you are a Computer Science student like me you probably started your coding journey by building small projects. Maybe a calculator app, a student management system or a simple CRUD website. At first, everything feels manageable. One project, one codebase, one server. Life is simple.

 

But as projects grow bigger things start getting messy. The code becomes huge. One small change breaks something else. Deployment becomes risky. Debugging feels like solving a mystery case before exams.

 

This is where Microservices Architecture comes into the picture.

 

In simple words, microservices means breaking one big application into many small, independent services. Each service does one specific job and runs separately.

 

And when it comes to Java development, Spring Boot makes building microservices much easier.

 

When I first learned this, I was honestly confused. I used to think why break something that is already working? But after building a few projects and seeing real-world system design it started making sense.

 

So in this blog, I will explain microservices using Spring Boot in a simple way just like we discuss topics before viva or semester exams.

 

(toc) #title=(Table of Content)

 

 

Microservices Architecture

Let’s first understand the idea.

 

What is Microservices Architecture?

Microservices architecture is a design style where:

• A large application is divided into small services
• Each service focuses on one business function
• Services run independently
• Services communicate using APIs

Basically, instead of building one huge application, we build many small applications that work together.

 

Real Life College Example

Think about your college.

 

Your college has different departments:

• Admissions Department
• Exam Cell
• Library
• Hostel Office
• Accounts Section

Each department has its own responsibility. If the library system goes down, exams still happen. If accounts server fails, hostel rooms still function.

 

This is exactly how microservices work.

 

Each service is like a department.

 

Monolithic vs Microservices

Most beginners start with monolithic architecture.

 

Monolithic Architecture

• Everything in one project
• One codebase
• One database
• One deployment

Example: A student portal where login, fees, exams, results everything is in one application.

 

Microservices Architecture

• Separate services
• Separate codebases
• Can have separate databases
• Independent deployment

Example:

• Login Service
• Fees Service
• Exam Service
• Result Service

All are separate but connected.

 

Quick Comparison Table

Feature	Monolithic	Microservices
Codebase	Single	Multiple small services
Deployment	One unit	Independent services
Scalability	Difficult	Easy
Maintenance	Hard for large apps	Easier
Technology	Usually same stack	Can use different stacks

 

Many students get confused here. They think microservices are always better. But actually, for small projects, monolithic is totally fine.

 

Microservices are useful when the system becomes large and complex.

 

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Creating Services Using Spring Boot

Now let’s talk about the practical part.

 

Spring Boot is one of the best frameworks for building microservices in Java. It saves time, reduces configuration headache and lets us focus on logic.

 

What is a Service?

A service is simply a small application that:

• Runs independently
• Has its own business logic
• Exposes APIs

Example services in a college project:

• Student Service → manages student data
• Course Service → handles course details
• Attendance Service → tracks attendance

 

Steps to Create a Microservice

Let’s say we want to create a Student Service.

 

Step 1: Create Spring Boot Project

Use Spring Initializr:

• Project: Maven
• Language: Java
• Dependencies:
  • Spring Web
  • Spring Data JPA
  • MySQL Driver
  • Lombok

 

Step 2: Create Model Class

This represents the database table.

Example: Student.java

• id
• name
• branch
• year

 

Step 3: Repository Layer

Interface that connects to database.

Example: StudentRepository extends JpaRepository

This helps us perform CRUD operations easily.

 

Step 4: Service Layer

Contains business logic.

Like:

• Add student
• Get student details
• Update student
• Delete student

 

Step 5: Controller Layer

This exposes REST APIs.

Example APIs:

• GET /students
• POST /students
• PUT /students/{id}
• DELETE /students/{id}

Now this service can run independently on a port like:

http://localhost:8081

And boom one microservice is ready.

 

Creating Multiple Services

Similarly, you create:

• Course Service → Port 8082
• Attendance Service → Port 8083

Each service is a separate Spring Boot project.

 

When I built my first microservices project, managing multiple projects felt messy. But once you understand structure it becomes smooth.

 

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Code Example (Simple Student Microservice)

Many students understand faster when they see code. So here’s a very basic Spring Boot microservice example for a Student Service.

 

1. pom.xml (Important Dependencies)

<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>

    <dependency>
        <groupId>com.mysql</groupId>
        <artifactId>mysql-connector-j</artifactId>
        <scope>runtime</scope>
    </dependency>

    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <optional>true</optional>
    </dependency>
</dependencies>

 

2. application.properties

server.port=8081

spring.datasource.url=jdbc:mysql://localhost:3306/college_db
spring.datasource.username=root
spring.datasource.password=yourpassword

spring.jpa.hibernate.ddl-auto=update
spring.jpa.show-sql=true

 

3. Student Entity

import jakarta.persistence.*;
import lombok.*;

@Entity
@Data
@NoArgsConstructor
@AllArgsConstructor
public class Student {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    private String name;
    private String branch;
    private int year;
}

 

4. Repository Layer

import org.springframework.data.jpa.repository.JpaRepository;

public interface StudentRepository extends JpaRepository<Student, Long> {
}

 

5. Service Layer

import org.springframework.stereotype.Service;
import java.util.List;

@Service
public class StudentService {

    private final StudentRepository repo;

    public StudentService(StudentRepository repo) {
        this.repo = repo;
    }

    public Student addStudent(Student s) {
        return repo.save(s);
    }

    public List<Student> getAllStudents() {
        return repo.findAll();
    }

    public Student getStudentById(Long id) {
        return repo.findById(id).orElse(null);
    }

    public void deleteStudent(Long id) {
        repo.deleteById(id);
    }
}

 

6. Controller Layer (REST APIs)

import org.springframework.web.bind.annotation.*;
import java.util.List;

@RestController
@RequestMapping("/students")
public class StudentController {

    private final StudentService service;

    public StudentController(StudentService service) {
        this.service = service;
    }

    @PostMapping
    public Student create(@RequestBody Student s) {
        return service.addStudent(s);
    }

    @GetMapping
    public List<Student> getAll() {
        return service.getAllStudents();
    }

    @GetMapping("/{id}")
    public Student getById(@PathVariable Long id) {
        return service.getStudentById(id);
    }

    @DeleteMapping("/{id}")
    public void delete(@PathVariable Long id) {
        service.deleteStudent(id);
    }
}

 

7. Main Class

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class StudentServiceApplication {
    public static void main(String[] args) {
        SpringApplication.run(StudentServiceApplication.class, args);
    }
}

 

Now if you run this project and test APIs using Postman:

• POST → Add student
• GET → View students
• DELETE → Remove student

Your microservice is live 🎉

 

You can build other services (Course, Attendance, etc.) the same way and connect them using REST APIs.

 

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API Communication Between Services

This part is very important.

 

Because microservices are separate applications, they need a way to talk to each other.

This communication happens using APIs.

 

Types of Communication

Synchronous Communication

One service calls another and waits for response.

Common tools:

• RestTemplate
• WebClient
• OpenFeign

Example:

Student Service wants course details.

It sends request to:

Course Service → /courses/{id}

Waits for response and then continues.

 

Asynchronous Communication

Services communicate using message queues.

They don’t wait for response.

Tools used:

• RabbitMQ
• Apache Kafka

Example:

Exam Service publishes result data.

Result Service consumes and processes later.

 

API Gateway

Instead of calling each service directly we can use an API Gateway.

API Gateway acts like a main entry point.

Client → API Gateway → Microservices

Benefits:

• Single entry point
• Security handling
• Load balancing
• Routing

 

Service Discovery

When services increase managing URLs becomes difficult.

Service Discovery helps services find each other dynamically.

Tool used:

• Eureka Server

So instead of hardcoding URLs services register themselves.

Very useful in large systems.

 

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Advantages of Microservices

Now comes the interesting part why companies love microservices.

 

Easy Scalability

If one service gets heavy traffic you can scale only that service.

Example:

During result time Result Service gets huge load. You scale only that.

No need to scale whole application.

 

Faster Development

Different teams work on different services.

Like group projects in college:

• One friend handles frontend
• One backend
• One database

Work becomes faster.

 

Independent Deployment

One service can be updated without affecting others.

Less risk during updates.

 

Better Fault Isolation

If one service crashes then whole system doesn’t stop.

System remains stable.

 

Technology Flexibility

Each service can use a different tech stack.

Example:

• Payment Service → Java
• Analytics Service → Python
• Frontend → React

 

Challenges

Microservices sound cool but come with challenges.

• Complex architecture
• Network latency
• Deployment complexity
• Requires DevOps knowledge
• Debugging across services is tough

 

So for beginners start small.

I personally prefer monolithic for mini projects and microservices for major projects.

 

Conclusion

So yeah microservices using Spring Boot is a powerful approach for building modern applications.

 

In simple words:

• Break big app into small services
• Each service runs independently
• Services communicate using APIs
• Spring Boot makes development easy

 

If you are preparing for placements or building final year projects learning microservices is definitely worth it.

 

Start with basics:

• REST APIs
• Spring Boot
• Databases

 

Then move to:

• API Gateway
• Service Discovery
• Messaging Queues

 

Don’t rush. Build small projects first. That’s how I learned and it really helps.

 

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FAQs

 

Is microservices difficult for beginners?

Not very difficult but concepts take time. Start with monolithic apps first.

Why is Spring Boot used for microservices?

Because it reduces configuration and helps build production ready apps fast.

Do microservices need multiple databases?

Not compulsory but usually each service manages its own database.

What is the difference between REST API and microservices?

REST API is a communication method. Microservices is an architecture style.

Is microservices important for placements?

Yes. Many product based companies use microservices architecture.