JAXB is Java Architecture for XML Binding which allows to map Java objects to XML and XML to Java objects.

Marshalling example : Converting a Java object into a XML file.

   
    import java.io.File;
    import javax.xml.bind.JAXBContext;
    import javax.xml.bind.JAXBException;
    import javax.xml.bind.Marshaller;

    public class JAXBExample {
        public static void main(String[] args) {

          Customer customer = new Customer();
          customer.setId(100);
          customer.setName("FindNerd");
          customer.setAge(29);

          try {

            File file = new File("C:\\XMLname.xml");
            JAXBContext jaxbContext = JAXBContext.newInstance(Customer.class);
            Marshaller jaxbMarshaller = jaxbContext.createMarshaller();

            // output pretty printed
            jaxbMarshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);

            jaxbMarshaller.marshal(customer, file);
            jaxbMarshaller.marshal(customer, System.out);

              } catch (JAXBException e) {
            e.printStackTrace();
              }     
        }
    }

Unmarshalling example : Converting XML content into a Java Object.

import java.io.File;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Unmarshaller;

public class JAXBExample {
    public static void main(String[] args) {

     try {

        File file = new File("C:\\XMLname.xml");
        JAXBContext jaxbContext = JAXBContext.newInstance(Customer.class);

        Unmarshaller jaxbUnmarshaller = jaxbContext.createUnmarshaller();
        Customer customer = (Customer) jaxbUnmarshaller.unmarshal(file);
        System.out.println(customer);

      } catch (JAXBException e) {
        e.printStackTrace();
      }

    }
}

Refrences