Java HTML/XML - 如何使用JAXB unmarshal XML

import java.util.ArrayList;
import java.util.List;

import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Marshaller;
import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.XmlTransient;

public class Main {
  public static void main(String[] args) throws JAXBException {
    JAXBContext context = JAXBContext.newInstance(Vehicals.class);
    Marshaller m = context.createMarshaller();
    m.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);

    Vehicals vehicals = new Vehicals();

    List<Car> cars = new ArrayList<Car>();
    Car c = new Car();
    c.setName("Mercedes");
    cars.add(c);

    c = new Car();
    c.setName("BMW");
    cars.add(c);
    vehicals.setCar(cars);
    m.marshal(vehicals, System.out);
  }
  @XmlRootElement
  public static class Vehicals {

    private List<Car> Car;

    public List<Car> getCar() {
      return Car;
    }

    public void setCar(List<Car> cars) {
      this.Car = cars;
    }
  }

  @XmlRootElement
  public static class Car {

    @XmlTransient
    private Long id;

    private String name;

    @XmlTransient
    private String code;

    public Long getId() {
      return id;
    }

    public void setId(Long id) {
      this.id = id;
    }

    public String getName() {
      return name;
    }

    public void setName(String name) {
      this.name = name;
    }

    public String getCode() {
      return code;
    }

    public void setCode(String code) {
      this.code = code;
    }
  }
}