JAXB (un)marshalling of xsd types: xsd:base64Binary and xsd:hexBinary

Question

JAXB maps both xsd:base64Binary and xsd:hexBinary types to byte[].

Given that I have a schema/a DOM Element representing each of these types such as:

<foo>ABCD</foo> for xsd:hexBinary and
<foo>YTM0NZomIzI2OTsmIzM0NTueYQ==</foo> for xsd:base64Binary ,

it's not clear how JAXB 2.1 handles it.

JAXB.unmarshal(new DOMSource(node), byte[].class) does not like the payload.
Neither does the following:

JAXBContext ctx = JAXBContext.newInstance(byte[].class); ctx.createUnmarshaller().unmarshal(node);

What's the correct way of handling these types? Thanks in advance.

Answer 1

The conversion between byte[] and the hexBinary or base64Binary representation is done via a correspondent XmlAdapter.

by default JAXB uses the included HexBinaryAdapter for converting byte[] to a String. I don't know if there is also an XmlAdapter which converts from/to base64 but that is no problem:

You can easily implement it yourself using an own XmlAdpater:

public final class Base64Adapter extends XmlAdapter<String, byte[]> {
    public byte[] unmarshal(String s) {
        if (s == null)
            return null;
        return org.apache.commons.codec.binary.Base64.decodeBase64(s);
    }

    public String marshal(byte[] bytes) {
        if (bytes == null)
            return null;
        return org.apache.commons.codec.binary.Base64.encodeBase64String(bytes);
    }
}

You can specify on a field/getter_setter level what should be processed by which adapter:

private class DataTestClass {

    @XmlJavaTypeAdapter(Base64Adapter.class)
    public byte[] base64Data = new byte[] { 0, 1, 2, 3, 4 };

    @XmlJavaTypeAdapter(HexBinaryAdapter.class)
    public byte[] hexbinData = new byte[] { 0, 1, 2, 3, 4 };

}