Spring multithreading issue

Dear experts

I am facing a multi threading issue in our spring environment.

In spring-config.xml we have
<bean id="jaxbConversionManager" class="com.junta.util.JAXBConversionManager"/>

JAXBConversionManager.java has unmarshal method
public class JAXBConversionManager{
	@SuppressWarnings("unchecked")
	public <T> T unmarshal(Document msg) {
		//convert from xml to object and return 
	}
	}

     
      
I have two classes

	public Class1 implements MessageListener{
	@Autowired
	private JAXBConversionManager jaxbConversionManager;
	
	private void method1(Document message)  throws Exception {
		Customer customer = jaxbConversionManager.unmarshal(message);
		LOGGER.info("Customer object1 is", customer.toString());
		moveForward(customer);
		}
	}
	
	public Class2 implements MessageListener{
	@Autowired
	private JAXBConversionManager jaxbConversionManager;
	
	private void method2(Document message) throws Exception {
		Customer customer = jaxbConversionManager.unmarshal(message);
		LOGGER.info("Customer object2 is", customer.toString());
		moveForward(customer);
	}
	}

     
      both above classes are using jaxbConversionManager object.
      
      Document message passed to method1() from Class1 was actually visible in Class2.method2() , i was able to confirm that in the log statement
      LOGGER.info("Customer object2 is", customer.toString()); --> prints message which came to method1
      
      This is most probably because jaxbConversionManager is not threadsafe. Any idea how i can make it threadsafe in a spring way.
      
      
      Thanks