Java HTML/XML - 如何创建XML序列化器

import java.io.StringReader;
import java.io.StringWriter;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;

import javax.xml.bind.JAXBContext;
import javax.xml.bind.Marshaller;
import javax.xml.bind.Unmarshaller;
import javax.xml.bind.annotation.XmlRootElement;

public class Main {
  public static void main(String args[]) throws Exception {
    Order o = new Order();
    o.setCustId(123);
    o.setDescription("New order");
    o.setOrderDate(new Date());

    List<Item> items = new ArrayList<Item>();

    Item i = new Item();
    i.setName("PC");
    i.setQty(10);
    items.add(i);

    i = new Item();
    i.setName("Box");
    i.setQty(4);

    items.add(i);

    o.setItems(items);
    // Write it
    JAXBContext ctx = JAXBContext.newInstance(Order.class);

    Marshaller m = ctx.createMarshaller();
    m.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);

    StringWriter sw = new StringWriter();
    m.marshal(o, sw);
    sw.close();
    System.out.println(sw.toString());

    // Read it back
    JAXBContext readCtx = JAXBContext.newInstance(Order.class);
    Unmarshaller um = readCtx.createUnmarshaller();

    Order newOrder = (Order) um.unmarshal(new StringReader(sw.toString()));
    System.out.println(newOrder);
  }

  @XmlRootElement
  public static class Order {

    int custId;
    Date orderDate;
    String description;
    List<Item> items;

    public void setCustId(int custId) {
      this.custId = custId;
    }

    public void setOrderDate(Date orderDate) {
      this.orderDate = orderDate;
    }

    public void setDescription(String description) {
      this.description = description;
    }

    public void setItems(List<Item> items) {
      this.items = items;
    }

    public int getCustId() {
      return custId;
    }

    public Date getOrderDate() {
      return orderDate;
    }

    public String getDescription() {
      return description;
    }

    public List<Item> getItems() {
      return items;
    }

    public String toString() {
      return "Order: " + custId + " - " + orderDate + " - " + description
          + " - " + items;
    }
  }

  public static class Item {

    String name;
    private int qty;

    public String getName() {
      return name;
    }

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

    public int getQty() {
      return qty;
    }

    public void setQty(int qty) {
      this.qty = qty;
    }

    public String toString() {
      return "Item:" + name + " - " + qty;
    }
  }
}