Spring bean initialisierungs probleme

[Bouyo]

Ich beschäftige mich gerad mit XML Marschelling via Spring. Ich hab hier folgende Dateien:

package com.javalearning.prototype.spring.xml;

public class TestClass {
		private boolean fooEnabled;
		
		public boolean isFooEnabled() {
		       return fooEnabled;
		}
		
		public void setFooEnabled(boolean fooEnabled) {
		       this.fooEnabled = fooEnabled;
		}
}

package com.javalearning.prototype.spring.xml;

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import javax.xml.transform.stream.StreamResult;
import javax.xml.transform.stream.StreamSource;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.oxm.Marshaller;
import org.springframework.oxm.Unmarshaller;

public class Application {
	   private static final String FILE_NAME = "settings.xml";

	   private TestClass testClass = new TestClass();
       
       private Marshaller   marshaller;
       private Unmarshaller unmarshaller;
       
       public void setMarshaller(Marshaller marshaller) {
    	   this.marshaller = marshaller;
       }
       
       public void setUnmarshaller(Unmarshaller unmarshaller) {
    	   this.unmarshaller = unmarshaller;
       }
       
       public void saveTestClass() throws IOException {
    	      FileOutputStream os = null;

    	      try {
    	          os = new FileOutputStream(FILE_NAME);
    	          
    	          this.marshaller.marshal(testClass, new StreamResult(os));
    	      } finally {
    	          if (os != null) {
    	             os.close();
    	          }
    	      }
       }
       
       public void loadTestClass() throws IOException {
    	      FileInputStream is = null;
    	      
    	      try {
    	          is             = new FileInputStream( FILE_NAME );
    	          this.testClass = (TestClass) this.unmarshaller.unmarshal(new StreamSource(is));
    	      } finally {
    	    	  if (is != null) {
    	             is.close();
    	          }
    	      }
       }
       
       
	/**
	 * @param args
	 */
	public static void main(String[] args) throws IOException {
		   ApplicationContext appContext =
				new ClassPathXmlApplicationContext("applicationContext.xml");
		   
		   Application application = (Application) appContext.getBean("application");
		   
		   application.saveTestClass();
		   application.loadTestClass();
	}

}

applicationContext.xml

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

<beans>
   <bean id="application" class="com.javalearning.prototype.spring.xml.Application">
       <property name="marshaller" ref="castorMarshaller" />
       <property name="unmarshaller" ref="castorMarshaller" />
   </bean>
   
   <bean id="castorMarshaller" class="org.springframework.oxm.castor.CastorMarshaller"/>
</beans>

und erhalte die Fehlermeldung:

Exception in thread "main" java.lang.NullPointerException
	at org.apache.logging.log4j.LogManager.getContext(LogManager.java:178)
	at org.apache.logging.log4j.jcl.LogFactoryImpl$PrivateManager.getContext(LogFactoryImpl.java:109)
	at org.apache.logging.log4j.jcl.LogFactoryImpl.getInstance(LogFactoryImpl.java:42)
	at org.apache.logging.log4j.jcl.LogFactoryImpl.getInstance(LogFactoryImpl.java:80)
	at org.apache.commons.logging.LogFactory.getLog(LogFactory.java:685)
	at org.springframework.context.support.AbstractApplicationContext.<init>(AbstractApplicationContext.java:154)
	at org.springframework.context.support.AbstractRefreshableApplicationContext.<init>(AbstractRefreshableApplicationContext.java:89)
	at org.springframework.context.support.AbstractRefreshableConfigApplicationContext.<init>(AbstractRefreshableConfigApplicationContext.java:59)
	at org.springframework.context.support.AbstractXmlApplicationContext.<init>(AbstractXmlApplicationContext.java:61)
	at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:136)
	at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:83)
	at com.javalearning.prototype.spring.xml.Application.main(Application.java:62)

Da ich ich noch recht unbedarft in Sachen Spring Konfiguration bin, find ich einfach das Problem nicht. Wer kann mir kurz schreiben was ich hier gerad falsch mache.