Introduction
The Spring @ConditionalOnWebApplication and @ConditionalOnNotWebApplication annotations let configuration be included depending on whether the application is a web application. A web application is any application that uses a Spring WebApplicationContext, defines a session scope, or has a StandardServletEnvironment.
Prerequisites
Java at least 8, Spring Boot 2.1.7 – 2.4.5
Project Setup
Create a maven based project in your favorite IDE or tool with the project name as spring-conditional-on-web-notweb-application.
Simple Class
I will create a simple class Module that will be used for both Spring @ConditionalOnWebApplication and @ConditionalOnNotWebApplication annotations to check whether the Module class is loaded or not using the said annotations.
package com.roytuts.spring.conditional.on.web.notweb.application;
public class Module {
}Main Class
The main class will be used to run our application.
package com.roytuts.spring.conditional.on.web.notweb.application;
import java.util.Arrays;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ApplicationContext;
@SpringBootApplication
public class SpringConditionalOnWebNotWebApp implements CommandLineRunner {
@Autowired
private ApplicationContext applicationContext;
public static void main(String[] args) {
SpringApplication.run(SpringConditionalOnWebNotWebApp.class, args);
}
@Override
public void run(String... args) throws Exception {
String[] beans = applicationContext.getBeanDefinitionNames();
Arrays.sort(beans);
boolean contains = Arrays.stream(beans).anyMatch("module"::equalsIgnoreCase);
if (contains) {
System.out.println("Module loaded");
} else {
System.out.println("Module not loaded");
}
}
}Spring Config Class
I will create a Spring Config class to use the Spring @ConditionalOnWebApplication and @ConditionalOnNotWebApplication and check the behavior of the application.
Example on @ConditionalOnWebApplication
Creating Config class with below source code:
package com.roytuts.spring.conditional.on.web.notweb.application;
import org.springframework.boot.autoconfigure.condition.ConditionalOnWebApplication;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
@Configuration
@ConditionalOnWebApplication
class SpringConfigOnWebNotWebApp {
@Bean
public Module module() {
return new Module();
}
}Testing the Application
Executing the main class you will see output as Module loaded. Therefore it’s a web application.
Example on @ConditionalOnNotWebApplication
Creating Config class with below source code:
package com.roytuts.spring.conditional.on.web.notweb.application;
import org.springframework.boot.autoconfigure.condition.ConditionalOnNotWebApplication;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
@Configuration
@ConditionalOnNotWebApplication
class SpringConfigOnWebNotWebApp {
@Bean
public Module module() {
return new Module();
}
}Testing the Application
Executing the main class you will see output as Module not loaded. Again it’s a web application and that’s why module was not loaded.