Spring Framework - @Conditional Examples

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

@Configuration
public class AppConfig {
    @Bean
    @Conditional(LocaleConditionUSA.class)
    public MyService myBeanA () {
        return new MyServiceA();
    }

    @Bean
    @Conditional(LocaleConditionCanada.class)
    public MyService myBeanB () {
        return new MyServiceB();
    }

    @Bean
    public ClientBean clientBean () {
        return new ClientBean();
    }
}

import org.springframework.context.annotation.Condition;
import org.springframework.context.annotation.ConditionContext;
import org.springframework.core.type.AnnotatedTypeMetadata;

import java.util.Locale;

public class LocaleConditionUSA implements Condition {

    @Override
    public boolean matches (ConditionContext context, AnnotatedTypeMetadata metadata) {
        return Locale.getDefault()
                     .equals(Locale.US);
    }
}

import org.springframework.context.annotation.Condition;
import org.springframework.context.annotation.ConditionContext;
import org.springframework.core.type.AnnotatedTypeMetadata;

import java.util.Locale;

public class LocaleConditionCanada implements Condition {

    @Override
    public boolean matches (ConditionContext context, AnnotatedTypeMetadata metadata) {
        return Locale.getDefault()
                     .equals(Locale.CANADA);
    }
}

import org.springframework.context.annotation.AnnotationConfigApplicationContext;

import java.util.Locale;

public class BeanConditionExample {

    public static void main(String[] args) {
        //In real application, System Locale would be used depending on your location.
        //Here we are setting it manually to test our example*/
        runApp(Locale.US);
        System.out.println("----------");
        runApp(Locale.CANADA);
    }

    public static void runApp(Locale locale) {
        System.out.printf("setting default locale: %s\n", locale);
        Locale.setDefault(locale);
        AnnotationConfigApplicationContext context =
                new AnnotationConfigApplicationContext(
                        AppConfig.class);

        ClientBean bean = context.getBean(ClientBean.class);
        System.out.printf("Injected MyService instance in ClientBean: %s\n", bean.getMyService()
                                                                                 .getClass()
                                                                                 .getSimpleName());
    }
}

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.*;
import org.springframework.stereotype.Component;

import java.util.Locale;


@Configuration
@ComponentScan(basePackageClasses = BeanConditionScanExample.class,
        useDefaultFilters = false,
        includeFilters = {@ComponentScan.Filter(
                type = FilterType.ASSIGNABLE_TYPE,
                value = {BeanConditionScanExample.MyClientBean.class,
                        BeanConditionScanExample.ServiceBeanImpl1.class,
                        BeanConditionScanExample.ServiceBeanImpl2.class})})

public class BeanConditionScanExample {

    public static void main(String[] args) {
        runApp(Locale.US);
        System.out.println("----------");
        runApp(Locale.CANADA);
    }

    public static void runApp(Locale locale) {
        System.out.printf("setting default locale: %s\n", locale);
        Locale.setDefault(locale);
        AnnotationConfigApplicationContext context =
                new AnnotationConfigApplicationContext(
                        BeanConditionScanExample.class);
        MyClientBean bean = context.getBean(MyClientBean.class);
        System.out.printf("Injected ServiceBean instance in MyClientBean: %s\n", bean.getServiceBean()
                                                                                     .getClass()
                                                                                     .getSimpleName());
    }

    @Component
    public static class MyClientBean {
        @Autowired
        private ServiceBean serviceBean;

        public ServiceBean getServiceBean() {
            return serviceBean;
        }
    }

    public interface ServiceBean {
    }

    @Component
    @Conditional(LocaleConditionUSA.class)
    public static class ServiceBeanImpl1 implements ServiceBean {
    }

    @Component
    @Conditional(LocaleConditionCanada.class)
    public static class ServiceBeanImpl2 implements ServiceBean {
    }
}