How to Run a CommandLineRunner Bean Conditionally in Spring Boot

This article shows different ways to run a CommandLineRunner bean conditionally in a Spring Boot application.

Table of contents:

• 1. Using @ConditionalOnProperty
• 2. Using Environment
• 3. Using Spring Profiles
• 4. Check the Presence of Other Beans
  • 4.1 Using @ConditionalOnBean
  • 4.2 Using @ConditionalOnMissingBean
• 5. Download Source Code
• 6. References

P.S. Tested with Spring Boot 3.1.2

1. Using @ConditionalOnProperty

The @ConditionalOnProperty annotation creates the bean only when a specific property exists or has a particular value.

In this example, the CommandLineRunner will only execute if the property db.init.enabled is set to true in the application.properties or application.yml file.

package com.mkyong;

import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
import org.springframework.stereotype.Component;

@Component
@ConditionalOnProperty(
      name = "db.init.enabled",
      havingValue = "true",
      matchIfMissing = false
)
public class DatabaseInitializer implements CommandLineRunner {

  @Override
  public void run(String... args) {

      System.out.println("This runs when 'db.init.enabled' property is true.");

  }

}

db.init.enabled=true

2. Using Environment

We can programmatically check conditions using the Environment bean and if statements.

In this example, the CommandLineRunner will only execute if the property db.init.enabled is set to true.

package com.mkyong;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.CommandLineRunner;
import org.springframework.core.env.Environment;
import org.springframework.stereotype.Component;

@Component
public class DatabaseInitializer implements CommandLineRunner {

  @Autowired
  private Environment env;

  @Override
  public void run(String... args) {

      if ("true".equals(env.getProperty("db.init.enabled"))) {
          System.out.println("This runs when 'db.init.enabled' property is true.");
      }

  }
}

3. Using Spring Profiles

The @Profile annotation creates the bean only when a specific Spring profile is active.

In this example, the CommandLineRunner will only execute if the Spring active profile is dev.

package com.mkyong;

import org.springframework.boot.CommandLineRunner;
import org.springframework.context.annotation.Profile;
import org.springframework.stereotype.Component;

@Component
@Profile("dev")
public class DatabaseInitializer implements CommandLineRunner {

  @Override
  public void run(String... args) {

      System.out.println("This runs when profile is to dev.");

  }
}

Different ways to set the Spring active profiles.

spring.profiles.active=dev

Spring Boot Maven Plugin

  ./mvnw spring-boot:run -Dspring-boot.run.profiles=dev  

java -jar

java -jar -Dspring.profiles.active=dev target/spring-boot-commandlinerunner-1.0.jar

4. Check the Presence of Other Beans

The @ConditionalOnBean and @ConditionalOnMissingBean annotations create the bean only when a specific bean is present or missing in the application context.

4.1 Using @ConditionalOnBean

The @ConditionalOnBean annotation creates the bean if the specific bean is present in the application context.

In this example, the CommandLineRunner will only execute if the BookController bean is present in the application context.

package com.mkyong;

import com.mkyong.book.BookController;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
import org.springframework.stereotype.Component;

@Component
@ConditionalOnBean(BookController.class)
public class DatabaseInitializer implements CommandLineRunner {

  @Override
  public void run(String... args) {

    //...

  }
}

4.2 Using @ConditionalOnMissingBean

The @ConditionalOnMissingBean annotation creates the bean if the specific bean is NOT present in the application context.

In this example, the CommandLineRunner will only execute if the BookController bean is NOT present in the application context.

package com.mkyong;

import com.mkyong.book.BookController;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
import org.springframework.stereotype.Component;

@Component
@ConditionalOnMissingBean(BookController.class)
public class DatabaseInitializer implements CommandLineRunner {

  @Override
  public void run(String... args) {

    //...

  }
}

5. Download Source Code

6. References

• Spring Docs – CommandLineRunner
• Set Spring Profile
• Spring Boot Profiles example
• Spring Boot CommandLineRunner Example
• Spring Boot @ConditionalOnProperty example

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