Conditional bean creation in Spring Boot - Mini Project: Build & Apply

Conditional Bean Creation in Spring Boot

📖 Scenario: You are building a Spring Boot application that needs to create a bean only when a specific condition is met. This is useful when you want to enable or disable features based on configuration or environment.

🎯 Goal: Learn how to create a bean conditionally using Spring Boot annotations so that the bean is only created when a certain property is set to true.

📋 What You'll Learn

Create a configuration class

Define a bean method inside the configuration class

Use a conditional annotation to create the bean only if a property is true

Add the property to application.properties to control bean creation

💡 Why This Matters

🌍 Real World

Conditional bean creation is useful in real applications to enable or disable features without changing code, just by changing configuration.

💼 Career

Understanding conditional bean creation helps you build flexible and configurable Spring Boot applications, a common requirement in professional Java development.

1

Create a configuration class

Create a class called FeatureConfig and annotate it with @Configuration.

Spring Boot

@Configuration
// Your code here

Need a hint?

The @Configuration annotation marks the class as a source of bean definitions.

2

Add a property to control the feature

Add a property called feature.enabled with value true to the application.properties file.

Spring Boot

import org.springframework.context.annotation.Configuration;

@Configuration
public class FeatureConfig {

}

# Add the property below in application.properties
# Your code here

Need a hint?

The application.properties file controls configuration properties for your Spring Boot app.

3

Define a conditional bean method

Inside FeatureConfig, create a method called featureBean that returns a new String with value "Feature is enabled". Annotate this method with @Bean and @ConditionalOnProperty(name = "feature.enabled", havingValue = "true").

Spring Boot

import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Bean;
import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;

@Configuration
public class FeatureConfig {
    // Your code here
}

# application.properties
feature.enabled=true

Need a hint?

The @ConditionalOnProperty annotation creates the bean only if the property matches the given value.

4

Complete the setup and verify bean creation

Ensure the FeatureConfig class imports @Bean and @ConditionalOnProperty annotations correctly and the application.properties file contains feature.enabled=true to enable the bean creation.

Spring Boot

import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Bean;
import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;

@Configuration
public class FeatureConfig {
    @Bean
    @ConditionalOnProperty(name = "feature.enabled", havingValue = "true")
    public String featureBean() {
        return "Feature is enabled";
    }
}

# application.properties
# Ensure feature.enabled=true is set
# Your code here

Need a hint?

Double-check your imports and property file to ensure the bean is created only when the property is true.