@Scope for bean scope in Spring Boot - Mini Project: Build & Apply

@Scope for bean scope in Spring Boot

📖 Scenario: You are building a simple Spring Boot application that manages user sessions. You want to control how Spring creates and manages your beans using the @Scope annotation.This helps you decide if a bean should be created once for the whole app or a new one each time it is needed.

🎯 Goal: Learn how to use the @Scope annotation to define bean scopes in Spring Boot.You will create a bean with singleton scope and then change it to prototype scope.

📋 What You'll Learn

Create a Spring Boot bean class named MyBean

Add @Component annotation to MyBean

Add @Scope annotation with ConfigurableBeanFactory.SCOPE_SINGLETON to MyBean

Change the scope to ConfigurableBeanFactory.SCOPE_PROTOTYPE using @Scope

💡 Why This Matters

🌍 Real World

Controlling bean scope is important in real applications to manage resources and behavior, like creating a new bean for each user request or sharing one bean for the whole app.

💼 Career

Understanding <code>@Scope</code> is essential for Spring developers to write efficient, maintainable, and scalable applications.

1

Create a Spring bean class with singleton scope

Create a class named MyBean in package com.example.demo. Annotate it with @Component and @Scope(ConfigurableBeanFactory.SCOPE_SINGLETON). Import org.springframework.stereotype.Component, org.springframework.context.annotation.Scope, and org.springframework.beans.factory.config.ConfigurableBeanFactory.

Spring Boot

package com.example.demo;

// Your code here

Need a hint?

Remember to import the correct classes and use @Component and @Scope annotations.

2

Add a simple method to MyBean

Inside the MyBean class, add a public method named getMessage that returns the string "Singleton Bean".

Spring Boot

package com.example.demo;

import org.springframework.stereotype.Component;
import org.springframework.context.annotation.Scope;
import org.springframework.beans.factory.config.ConfigurableBeanFactory;

@Component
@Scope(ConfigurableBeanFactory.SCOPE_SINGLETON)
public class MyBean {
    // Add getMessage method here
}

Need a hint?

Define a public method named getMessage that returns the exact string "Singleton Bean".

3

Change the bean scope to prototype

Modify the @Scope annotation on MyBean to use ConfigurableBeanFactory.SCOPE_PROTOTYPE instead of SCOPE_SINGLETON.

Spring Boot

package com.example.demo;

import org.springframework.stereotype.Component;
import org.springframework.context.annotation.Scope;
import org.springframework.beans.factory.config.ConfigurableBeanFactory;

@Component
// Change scope to prototype below
@Scope(ConfigurableBeanFactory.SCOPE_SINGLETON)
public class MyBean {
    public String getMessage() {
        return "Singleton Bean";
    }
}

Need a hint?

Replace SCOPE_SINGLETON with SCOPE_PROTOTYPE inside the @Scope annotation.

4

Add a Spring Boot application class to test the bean scope

Create a class named DemoApplication in package com.example.demo. Annotate it with @SpringBootApplication. Add a main method that runs SpringApplication.run(DemoApplication.class, args). Import org.springframework.boot.SpringApplication and org.springframework.boot.autoconfigure.SpringBootApplication.

Spring Boot

package com.example.demo;

// Add DemoApplication class here
// Your code here

Need a hint?

Create the main Spring Boot application class with @SpringBootApplication and a main method that starts the app.