JAXB Adding attributes to a XmlElement for simple data types_问答_开发者

JAXB Adding attributes to a XmlElement for simple data types

开发者 https://www.devze.com 2023-03-03 04:26 出处：网络

I want to add some attributes to Xml Elements using JAXB when marshalling from JavaBeans. The Xml Elements are simple data types like String. So I do not want to create new Classes. For exa开发者_如何

<notifications>
<date>04/20/2011</date>
<subject creditcard_num="22678" checknum="8904">Credit Card Charge Back</subject>
<body payment_amount="34.00" return_status="charged back">some text</body>
</notifications

I do not want to define subject and body as separate classes.

-Anand

My solution require defining a class for subject and body, but the desired output will be as requested I use @XmlValue for the message and @XmlAttribute for the attributes

@Test
public void testAll() throws JAXBException
{
    String msg = "<notifications><date>04/20/2011</date><subject creditcard_num='22678' checknum='8904'>Credit Card Charge Back</subject><body payment_amount='34.00' return_status='charged back'>some text</body></notifications>";
    Notifications tested = (Notifications) JAXBContext.newInstance(Notifications.class).createUnmarshaller().unmarshal(new StringReader(msg));
    assertEquals("Credit Card Charge Back",tested.subject.value);
    assertEquals("8904",tested.subject.checknum);
    assertEquals("22678",tested.subject.creditcard_num);
}
@XmlRootElement
public static class Notifications{
    public String date;
    public Subject subject;
}

public static class Subject
{
    @XmlValue
    public String value;

    @XmlAttribute(name="creditcard_num")
    public String  creditcard_num;

    @XmlAttribute(name="checknum")
    public String  checknum;
}

NOTE:I only wrote the subject part, I wonder if using @XmlPath can be used to remove the need for different classes

You could use EclipseLink JAXB (MOXy)'s @XmlPath annotation to solve this problem (I'm the MOXy tech lead):

Notifications

import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlRootElement;

import org.eclipse.persistence.oxm.annotations.XmlPath;

@XmlRootElement
@XmlAccessorType(XmlAccessType.FIELD)
public class Notifications {

    private String date;

    @XmlPath("subject/@creditcard_num")
    private String creditcardNum;

    @XmlPath("subject/@checknum")
    private String checknum;

    private String subject;

    @XmlPath("body/@payment_amount")
    private String paymentAmount;

    @XmlPath("body/@return_status")
    private String returnStatus;

    private String body;

}

jaxb.properties

To use MOXy as your JAXB implementation you need to put a file named jaxb.properties in the same package as your model classes with the following entry:

javax.xml.bind.context.factory=org.eclipse.persistence.jaxb.JAXBContextFactory

Demo

import java.io.File;

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

public class Demo {

    public static void main(String[] args) throws Exception {
        JAXBContext jc = JAXBContext.newInstance(Notifications.class);

        Unmarshaller unmarshaller = jc.createUnmarshaller();
        Notifications notifications = (Notifications) unmarshaller.unmarshal(new File("input.xml"));

        Marshaller marshaller = jc.createMarshaller();
        marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
        marshaller.marshal(notifications, System.out);
    }

}

For More Information:

http://bdoughan.blogspot.com/2010/07/xpath-based-mapping.html
http://bdoughan.blogspot.com/2010/09/xpath-based-mapping-geocode-example.html
http://bdoughan.blogspot.com/2011/03/map-to-element-based-on-attribute-value.html