Consider this example –
I have a class called Report that has a field of type Message. The Message class has a field called “body” which is a string. “body” can be any string, but sometimes it contains properly formatted XML content. How can I ensure that when the “body” contains XML content, the serialization takes the form of an XML structure rather than what it gives at present?
Here is the code with the output –
Report class
import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.XmlType;
@XmlRootElement(name = "Report")
@XmlType(propOrder = { "message"})
public class Report
{
private Message message;
public Message getMessage() { return message; }
public void setMessage(Message m) { message = m; }
}
Message class
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlType;
@XmlType(propOrder = { "body" })
public class Message
{
private String body;
public String getBody() { return body; }
@XmlElement
public void setBody(String body) { this.body = body; }
}
Main
import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Marshaller;
public class SerializationTest
{
public static void main(String args[]) throws Exception
{
JAXBContext jaxbContext = JAXBContext.newInstance(Report.class);
Marshaller jaxbMarshaller = jaxbContext.createMarshaller();
jaxbMarshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
Report report = new Report();
Message message = new Message();
message.setBody("Sample report message.");
report.setMessage(message);
jaxbMarshaller.marshal(report, System.out);
message.setBody("<rootTag><body>All systems online.</body></rootTag>");
report.setMessage(message);
jaxbMarshaller.marshal(report, System.out);
}
}
The output is as follows –
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<Report>
<message>
<body>Sample report message.</body>
</message>
</Report>
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<Report>
<message>
<body><rootTag><body>All systems online.</body></rootTag></body>
</message>
</Report>
As you can see in the above output, for the second instance of “body”, the serialization produced
<body><rootTag><body>All systems online.</body></rootTag></body>
instead of
<body><rootTag><body>All systems online.</body></rootTag></body>
How to solve this problem?
Note: I’m the EclipseLink JAXB (MOXy) lead and a member of the JAXB (JSR-222) expert group.
This use case is mapped using the
@XmlAnyElementannotation and specifying aDOMHandler. There appears to be bug when doing this with the JAXB RI, but the following use case works with EclipseLink JAXB (MOXy).BodyDomHandler
By default a JAXB impleemntation will represent unmapped content as a DOM node. You can leverage a
DomHandlerto an alternate representation of the DOM, In this case we will represent the DOM as aString.Message
Below is how you would specify the
@XmlAnyElementannotation on yourMessageclass.Output
Below is the output from running your
SerialziationTest:For More Information
NOTE – Bug in JAXB RI
There appears to be a bug in the JAXB reference implementation, and the example code will result in a stack trace like the following: