What’s @Conditional annotation in Spring Framework? Instance Tutorial

On this instance, we aren’t going to retailer the values in any database. So solely used the spring-boot-starter dependency as proven within the following pom.xml file.

<?xml model="1.0" encoding="UTF-8"?>

<challenge xmlns="http://maven.apache.org/POM/4.0.0" 
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 
                    https://maven.apache.org/xsd/maven-4.0.0.xsd">

<modelVersion>4.0.0</modelVersion>

<dad or mum>

<groupId>org.springframework.boot</groupId>

<artifactId>spring-boot-starter-parent</artifactId>

<model>2.5.2</model>

<relativePath/> <!-- lookup dad or mum from repository -->

</dad or mum>

<groupId>com.instance</groupId>

<artifactId>studentproject</artifactId>

<model>0.0.1-SNAPSHOT</model>

<title>studentproject</title>

<description>Demo challenge for Spring Boot</description>

<properties>

<java.model>11</java.model>

</properties>

<dependencies>

<dependency>

<groupId>org.springframework.boot</groupId>

<artifactId>spring-boot-starter</artifactId>

</dependency>



<dependency>

<groupId>org.springframework.boot</groupId>

<artifactId>spring-boot-starter-test</artifactId>

<scope>take a look at</scope>

</dependency>

</dependencies>

<construct>

<plugins>

<plugin>

<groupId>org.springframework.boot</groupId>

<artifactId>spring-boot-maven-plugin</artifactId>

</plugin>

</plugins>

</construct>

</challenge>

StudentBean class

That is an empty bean class to indicate you the method.

public class StudentBean {

 non-public String title;
 public String getName() {
  return title;
 }

public void setName(String title) {
  this.title = title;
  }
}

3. TestBeanCondition Class

That is the category that implements the Situation interface and supplies the situation for creating the StudentBean. As you’ll be able to see within the matches technique it checks if the setting comprises the property “scholar”.

import org.springframework.context.annotation.Situation;
import org.springframework.context.annotation.ConditionContext;
import org.springframework.core.env.Setting;
import org.springframework.core.sort.AnnotatedTypeMetadata;

public class StudentBeanCondition implements Situation {
@Override
public boolean matches(ConditionContext context, AnnotatedTypeMetadata metadata) {
   Setting setting = context.getEnvironment();
   return setting.containsProperty("scholar");
  }
}

4. StudentBeanConfig class

That is the category the place TestBean is created, you’ll be able to see the @Conditional annotation used right here with the category that gives the situation.

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

@Configuration
@PropertySource(worth="classpath:config/take a look at.properties", ignoreResourceNotFound=true)
public class StudentBeanConfig {

@Bean
@Conditional(StudentBeanCondition.class)
public StudentBean studentBean() {
    System.out.println("scholar bean creation");
    return new StudentBean();
  }
}

5. Check the code

Then take a look at the code utilizing the beneath code snippet.

import org.springframework.context.annotation.AnnotationConfigApplicationContext;

public class StudentApplication {

public static void primary( String[] args ){
  AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext
(StudentBeanConfig.class);

  StudentBean sb = (StudentBean)context.getBean("studnetBean");
  sb.setName("Angela");
  System.out.println("" + sb.getName());
  context.shut();
  }
}

Output

If every thing goes nicely, the code reveals the bean with the testing quotes and the scholar title.

That is all about what’s @Conditional annotation in Spring and How one can use it. The @Conditional annotation receives a category title that implements the Situation interface and creates the bean if that situation is matched.

If the situation you are looking for to construct is merely the inverse of one other situation, you’ll be able to prolong from it and override the matches technique because the inverse of executing the dad or mum class’s matches technique.

You could expressly outline the situation. Spring will register the bean and add it to the appliance context if these situations are met. That’s all for this tutorial and I hope the article served you no matter you had been searching for.