Altering the XML header produced by the JAXB marshaller

Question

I am currently using the following code to marshal an object into an xml string

    JAXBContext context;

    try {
        context = JAXBContext.newInstance(heartbeat.getClass());
        StringWriter writer = new StringWriter();
        Marshaller marshaller = context.createMarshaller();

        heartbeat.setHeader(header);
        heartbeat.setHeartbeatEvent(event);

        marshaller.marshal(heartbeat, writer);
        String stringXML = writer.toString();
        return stringXML;

    } catch (JAXBException e) {
        throw new RuntimeException("Problems generating XML in specified "
                + "encoding, underlying problem is " + e.getMessage(),
                e);
    }

Which produces the following header

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>

My desired output is the following

<?xml version=\"1.0\"?>

By adding this to the marshaller

marshaller.setProperty(Marshaller.JAXB_FRAGMENT, Boolean.FALSE);
marshaller.setProperty("com.sun.xml.bind.xmlHeaders", "<?xml version=\"1.0\"?>");

I receive

<?xml version="1.0" encoding="UTF-8" standalone="yes"?><?xml version="1.0"?>

and changing the JAXB_FRAGMENT property to TRUE removes the header entirely. I have been following the JAXB - Remove 'standalone="yes"' from generated XML thread attempting to solve the problem but I have had no luck so far. Can someone please give me some insight on how to get my desired header from the JAXB marshaller?

score 25 · Accepted Answer · edited Aug 22 '17 at 20:08

25

When marshalling to an OutputStream using a combination of the following produces the expected output.

    marshaller.setProperty("com.sun.xml.bind.xmlHeaders", "<?xml version=\"1.0\"?>");
    marshaller.setProperty(Marshaller.JAXB_FRAGMENT, true);

The problem you are seeing occurs when you marshal to a Writer, which appears to be a bug in the JAXB reference implementation. You can raise an issue at the link below:

https://java.net/jira/browse/JAXB/

You could always do:

JAXBContext context;

try {
    context = JAXBContext.newInstance(heartbeat.getClass());
    StringWriter writer = new StringWriter();
    writer.append("<?xml version=\"1.0\"?>");
    Marshaller marshaller = context.createMarshaller();
    marshaller.setProperty(Marshaller.JAXB_FRAGMENT, true);

    heartbeat.setHeader(header);
    heartbeat.setHeartbeatEvent(event);

    marshaller.marshal(heartbeat, writer);
    String stringXML = writer.toString();
    return stringXML;

} catch (JAXBException e) {
    throw new RuntimeException("Problems generating XML in specified "
            + "encoding, underlying problem is " + e.getMessage(),
            e);
}

EclipseLink JAXB (MOXy) also supports the com.sun.xml.bind.xmlHeaders and it works correctly when marshalling to a Writer (I'm the MOXy lead)

http://blog.bdoughan.com/2011/05/specifying-eclipselink-moxy-as-your.html

edited Aug 22 '17 at 20:08

Pyves

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answered Aug 26 '13 at 19:56

bdoughan

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I get a `PropertyException` when setting the `sun` property. – Sotirios Delimanolis Aug 26 '13 at 20:01
On MOXy? Which version are you using? – bdoughan Aug 26 '13 at 20:02
No MOxy. I assumed the property was used with the Java implementation. – Sotirios Delimanolis Aug 26 '13 at 20:03
@SotiriosDelimanolis - I am able to set the property on the `Marshaller` from the JAXB implementation included in JDK 1.7.0_25-b15 for the Mac (as well as MOXy). – bdoughan Aug 26 '13 at 20:06
1

I'm on JDK 1.7.0_21 on Windows. The exception occurs at `at javax.xml.bind.helpers.AbstractMarshallerImpl.setProperty(Unknown Source)` and `at com.sun.xml.internal.bind.v2.runtime.MarshallerImpl.setProperty(Unknown Source)`. It's not one of the properties it looks for. – Sotirios Delimanolis Aug 26 '13 at 20:09
For propertyException see this: http://stackoverflow.com/a/33199912/1386911 – Daniel Hári Mar 07 '17 at 13:57
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Daniel Hári proposed in an edit that with newer JDKs the property to set is `"com.sun.xml.internal.bind.xmlHeaders"`. – Ole V.V. Mar 07 '17 at 14:34

Gopi Krishna · Answer 2 · 2015-10-01T16:40:53.397

7

This worked for me

marshaller.setProperty("com.sun.xml.internal.bind.xmlHeaders", "<?xml version=\"1.0\" encoding=\"UTF-8\"?>");

edited Oct 01 '15 at 16:40

answered Oct 01 '15 at 16:32

Gopi Krishna

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"com.sun.xml.internal.bind.xmlHeaders" works when using jaxb from jdk 1.8 (at least on windows with java 1.8.0_60) – dosw Feb 03 '16 at 16:13

plejaden · Answer 3 · 2022-01-17T15:41:20.020

In JAXB 3.0.1 the above mentioned constants cause a PropertyException:

 jakarta.xml.bind.PropertyException: name: com.sun.xml.bind.xmlDeclaration value: false

In this case, the XML preamble can be configured with these marshaller constants:

marshaller.setProperty("org.glassfish.jaxb.xmlHeaders", "<?xml version=\"1.0\" encoding=\"UTF-8\" ?>");
marshaller.setProperty(Marshaller.JAXB_FRAGMENT, true);

https://eclipse-ee4j.github.io/jaxb-ri/3.0.0/docs/ch05.html

Altering the XML header produced by the JAXB marshaller

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