Developing JAXB Applications Using EclipseLink MOXy, Release 2.4
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Refreshing Metadata

Introduced in EclipseLink MOXy 2.3, you can refresh the JAXBContext metadata at runtime. This allows you to make changes to existing mappings in a live application environment and see those changes immediately without having to create a new JAXBContext.

In order to use the Metadata Refresh feature, your metadata information must be provided in one of the following formats:

Example 8-1 Refreshing Metadata

This example will be bootstrapped from the following EclipseLink OXM file:

<?xml version="1.0"?>
        <java-type name="Root">
                <xml-element java-attribute="name" name="orig-name"/>

The JAXBContext is created in the standard way:

ClassLoader classLoader = ClassLoader.getSystemClassLoader();
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder db = dbf.newDocumentBuilder();
InputStream metadataStream = classLoader.getResourceAsStream("example/eclipselink-oxm.xml";
Document metadataDocument = db.parse(metadataStream);
Map<String, Object> props = new HashMap<String, Object>(1);
props.put(JAXBContextProperties.OXM_METADATA_SOURCE, metadataDocument);
JAXBContext context = JAXBContextFactory.createContext(new Class[] { Root.class }, props);

At this point, if we were to marshal a Root object to XML, it would look like this:


For this example, we will modify the metadata Document directly to change the XML name for the name field. We can then refresh the metadata using the refreshMetadata() API:

Element xmlElementElement = (Element) metadataDocument.getElementsByTagNameNS("", "xml-element").item(0);
xmlElementElement.setAttribute("name", "new-name");

After refreshing metadata, the same Root object will be marshalled as follows: