Bean concept in Spring in Spring Boot - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

What is the primary purpose of a Spring Bean?

In Spring Framework, what is the main role of a Bean?

A It is a configuration file that defines application properties.

B It is a database connection object used for querying data.

C It is an object managed by the Spring container to provide application functionality.

D It is a user interface component for web pages.

💡 Hint

Think about what Spring manages to help build applications.

A Spring Bean is an object that the Spring container creates, manages, and wires together to build the application.

❓ component_behavior

intermediate

What happens when you annotate a class with @Component in Spring?

Consider a class annotated with @Component. What does Spring do with this class during application startup?

A Spring creates an instance of the class and registers it as a Bean in the application context.

B Spring ignores the class unless it is explicitly instantiated in code.

C Spring converts the class into a database entity automatically.

D Spring uses the class only for configuration properties.

💡 Hint

Think about how Spring detects and manages components automatically.

The @Component annotation tells Spring to create and manage an instance of the class as a Bean.

❓ state_output

advanced

What is the scope of a Bean annotated with @Scope("prototype")?

Given a Spring Bean annotated with @Scope("prototype"), what is the behavior when the Bean is requested multiple times?

A A new instance of the Bean is created each time it is requested.

B The same single instance of the Bean is shared across all requests.

C The Bean is created once per HTTP session and reused.

D The Bean is created once per web request and discarded afterward.

💡 Hint

Prototype scope means multiple instances instead of one.

Beans with prototype scope are created fresh each time they are requested from the container.

📝 Syntax

advanced

Which code snippet correctly defines a Bean using Java configuration in Spring?

Select the correct Java method to define a Bean in a @Configuration class.

Spring Boot

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class AppConfig {
    // Which method is correct?
}

A public MyService myService() { return new MyService(); }

B @Bean public MyService myService() { return new MyService(); }

C @Bean MyService myService { return new MyService(); }

D @Bean public void myService() { new MyService(); }

💡 Hint

Look for the correct method signature and annotation.

The method must be annotated with @Bean, have a return type, and return the Bean instance.

🔧 Debug

expert

What error occurs if two Beans have the same name in Spring context?

If two Beans are defined with the same name in Spring, what happens when the application starts?

A Spring merges both Beans into one automatically.

B Spring silently uses the first Bean and ignores the second one.

C Spring creates both Beans with different internal names without error.

D Spring throws a BeanDefinitionOverrideException or a similar error about duplicate Bean names.

💡 Hint

Spring does not allow two Beans with the same name by default.

Spring throws an error because Bean names must be unique to avoid confusion in dependency injection.