Beispiel einer rein Annotation basierten Spring Konfiguration

[Thomas Darimont]

Hallo,

inspiriert von diesem Blogeintrag (und einer kleinen Diskussion im StudiVz...)
http://blog.interface21.com/main/2006/11/28/a-java-configuration-option-for-spring/
Hier mal noch ein Beispiel zu solch einer rein auf Annotations basierten Spring Konfiguration:

Die Implementierung AnnotationApplicationContext gibts hier:
http://sourceforge.net/project/showfiles.php?group_id=73357&package_id=213222

BeanA:

/**
 * 
 */
package de.tutorials;

/**
 * @author Tom
 * 
 */

public class BeanA {

    protected BeanB a;
    protected BeanB b;

    /**
     * @return the a
     */
    public BeanB getA() {
        return a;
    }

    /**
     * @param a
     *            the a to set
     */
    public void setA(BeanB a) {
        this.a = a;
    }

    /**
     * @return the b
     */
    public BeanB getB() {
        return b;
    }

    /**
     * @param b
     *            the b to set
     */
    public void setB(BeanB b) {
        this.b = b;
    }

    @Override
    public String toString() {
        return super.toString() + " " + this.getA() + " " + this.getB();
    }
}

BeanB:

/**
 * 
 */
package de.tutorials;

/**
 * @author Tom
 * 
 */

public class BeanB {
}

/**
 * 
 */
package de.tutorials;

import java.util.Arrays;

import org.springframework.beans.factory.annotation.Autowire;
import org.springframework.beans.factory.annotation.Bean;
import org.springframework.beans.factory.annotation.Configuration;
import org.springframework.beans.factory.annotation.Scope;
import org.springframework.context.ApplicationContext;
import org.springframework.context.java.AnnotationApplicationContext;

/**
 * @author Tom
 * 
 */
@Configuration()
public class AnnotationOnlySpringConfigurationExample {

	@Bean(autowire = Autowire.BY_TYPE)
	public BeanA beanA() {
		return new BeanA();
	}

	@Bean(scope=Scope.PROTOTYPE)
	public BeanB beanB() {
		return new BeanB();
	}

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		ApplicationContext applicationContext = new AnnotationApplicationContext(
				AnnotationOnlySpringConfigurationExample.class.getName());
		System.out.println(Arrays.toString(applicationContext.getBeanDefinitionNames()));
		BeanA beanA = (BeanA) applicationContext.getBean("beanA");
		System.out.println(beanA);
	}
}

Ausgabe:

14.01.2007 16:32:29 org.springframework.core.CollectionFactory <clinit>
INFO: JDK 1.4+ collections available
class de.tutorials.AnnotationOnlySpringConfigurationExample
14.01.2007 16:32:29 org.springframework.context.support.AbstractRefreshableApplicationContext refreshBeanFactory
INFO: Bean factory for application context [org.springframework.context.java.AnnotationApplicationContext;hashCode=29193342]: org.springframework.beans.factory.support.DefaultListableBeanFactory defining beans [de.tutorials.AnnotationOnlySpringConfigurationExample]; root of BeanFactory hierarchy
14.01.2007 16:32:29 org.springframework.context.support.AbstractApplicationContext refresh
INFO: 3 beans defined in application context [org.springframework.context.java.AnnotationApplicationContext;hashCode=29193342]
14.01.2007 16:32:29 org.springframework.context.support.AbstractApplicationContext initMessageSource
INFO: Unable to locate MessageSource with name 'messageSource': using default [org.springframework.context.support.DelegatingMessageSource@1975b59]
14.01.2007 16:32:29 org.springframework.context.support.AbstractApplicationContext initApplicationEventMulticaster
INFO: Unable to locate ApplicationEventMulticaster with name 'applicationEventMulticaster': using default [org.springframework.context.event.SimpleApplicationEventMulticaster@913fe2]
14.01.2007 16:32:29 org.springframework.beans.factory.support.DefaultListableBeanFactory preInstantiateSingletons
INFO: Pre-instantiating singletons in factory [org.springframework.beans.factory.support.DefaultListableBeanFactory defining beans [de.tutorials.AnnotationOnlySpringConfigurationExample,beanA,beanB]; root of BeanFactory hierarchy]
14.01.2007 16:32:29 org.springframework.aop.framework.DefaultAopProxyFactory <clinit>
INFO: CGLIB2 available: proxyTargetClass feature enabled
[de.tutorials.AnnotationOnlySpringConfigurationExample, beanA, beanB]
de.tutorials.BeanA@1dfafd1 de.tutorials.BeanB@8fce95 de.tutorials.BeanB@143c8b3

Diese Art der Konfiguration mit "nativen" Sprachmitteln erinnert sehr an die Konfiguration bei Django (Python) und Ruby on Rails (Ruby).

Bin zwar kein großer Fan davon aber interessant ist's trotzdem ;-)

Gruß Tom