Since parsing is done using JAXB, I think we still need to use a Collection (Set is alright, although it does not take advantage of any uniqueness feature of PropertyMetaData). Maps would be mapping somehow differently in JAXB, and AFAICT you can't actually use a HashMap per se as the mapped property, much less so a LinkedHashMap. I would rather think of using a set for JAXB and a map internally, something like this: | ... | @XmlTransient | private Map<Object, PropertyMetaData> propertyMetaData = ; | | | public void setPropertyMetaData(Set<PropertyMetaData> parsedProperties) { | this.propertyMetaData = new LinkedHashMap(); | <add all the elements of parsedProperties into the Map> | } | | | @XmlElement("property") | public Set<PropertyMetaData> getPropertyMetaData() { | return new HashSet<PropertyMetaData>(this.propertyMetaData.values(); | } | View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4247038#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...