Hello, I need to parse this xml :

 <?xml version="1.0" encoding="UTF-8"?> <Orders> <AddOrder book="book-1" operation="SELL" price="100.50" volume="81" orderId="1" /> <AddOrder book="book-3" operation="BUY" price=" 99.50" volume="86" orderId="2" /> <DeleteOrder book="book-2" orderId="104" /> <AddOrder book="book-1" operation="BUY" price=" 99.70" volume="16" orderId="3" /> <AddOrder book="book-3" operation="SELL" price="100.00" volume="80" orderId="4" /> <DeleteOrder book="book-2" orderId="104" /> <AddOrder book="book-3" operation="SELL" price="100.80" volume="24" orderId="149" /> </Orders>

I'm trying to do this with JAXB . This is my first acquaintance with him on this, do not throw tomatoes please. I'm trying to do it like this:

Application class:

 import javax.xml.bind.annotation.XmlElement; import javax.xml.bind.annotation.XmlRootElement; import javax.xml.bind.annotation.XmlType; @XmlRootElement(name = "AddOrder") @XmlType(propOrder = {"book","operation","volume","price","orderId"}) public class Order { private String book; private String operation; private int volume; private float price; private int orderId; public String getBook() { return book; } @XmlElement public void setBook(String book) { this.book = book; } public String getOperation() { return operation; } @XmlElement public void setOperation(String operation) { this.operation = operation; } public int getVolume() { return volume; } @XmlElement public void setVolume(int volume) { this.volume = volume; } public float getPrice() { return price; } @XmlElement public void setPrice(float price) { this.price = price; } public int getOrderId() { return orderId; } @XmlElement public void setOrderId(int orderId) { this.orderId = orderId; } }

The parser itself:

 import javax.xml.bind.JAXBContext; import javax.xml.bind.JAXBException; import javax.xml.bind.Unmarshaller; import java.io.File; public class JaxbParser implements Parser { @Override public Object getObject(File file, Class c) throws JAXBException { JAXBContext context = JAXBContext.newInstance(c); Unmarshaller unmarshaller = context.createUnmarshaller(); return unmarshaller.unmarshal(file); } }

Well, when I try to try this thing:

  public static void main(String[] args) throws JAXBException { Parser parser = new JaxbParser(); File file = new File("/Users/pavel/Desktop/order1.xml"); Order order = (Order) parser.getObject(file, Order.class); System.out.println(order); }

Everything falls with an error:

unexpected element (uri: "", local: "Orders"). Expected elements are <{} AddOrder>

And I would think that the whole thing is in the tag at the beginning of the file, but when I left one line in the file <AddOrder book="book-1" operation="SELL" price="100.50" volume="81" orderId="1" /> (everything else was deleted) as an experiment, then an object was created of course, but with empty fields, that is, data, so it was not recorded in the object.

Please help me figure out what I'm doing wrong. How do I parse this file?

    2 answers 2

    You don't have one element in xml, but a collection. Even two. It is necessary to make a "root class", which will describe the root xml-ki and load through it.

    1. Remove the @XmlRootElement annotation (name = "AddOrder") from the Order class

    2. Create a class Orders

      @XmlRootElement (name = "Orders") public class Orders {private List addOrders; private List deleteOrders;

       @XmlElement(name = "AddOrder") public List<Order> getAddOrders... public void setAddOrders... @XmlElement(name = "DeleteOrder") public List<Order> getDeleteOrders... public void setDeleteOrders...

      }

    3. Load xml using this class:

      Orders orders = (Orders) parser.getObject (file, Orders.class);

    And about each order:

    Here properties are represented by attributes. Therefore, in the Order class, the getter and property setters must be marked with @XmlAttribute, not @XmlElement.

      1. Describe the schema of your XML Scheme document
      2. Using the JAXB Compiler, create a set of classes

      3. Use Unmarshaller

         JAXBContext jc = JAXBContext.newInstance("<имя пакета>") Unmarshaller u = jc.createUnmarshaller(); Order o = (Order) u.unmarshal(new FileInputStream("<xml файл>"));
      • >> Describe the outline of your document << didn’t you describe it in the Order class? Simply, even when the document scheme is reduced to a single line <AddOrder book = "book-1" operation = "SELL" price = "100.50" volume = "81" orderId = "1" /> the code still does not work. That's what confuses me, when I print the object I have the string null and primitives 0. Although it seems to be compiled. - Pavel
      • The schema is an xml document. usually with the xsd extension. I added a link in response. - Mikhail Vaysman
      • And where to place the file scheme? - Pavel
      • @Pavel no matter where. It is needed at compile time. - Mikhail Vaysman
      • @MikhailVaysman he does not need any schemes. He has errors in the annotations and the class is not enough. Instead of indicating where the errors are, you are proposing to get into the xsd swamp. - MuFF