jaxb difference bwteen java 7 and java 6 - jaxb

Question

I have a jaxb code which used to work in java 6, but after I update to java 7, it generated xml file differently.
in java 6, the file looks like this:
<ns2:recommendation>
<id>4</id>
<type>ARTICLE</type>
<name>Application-4</name>
<description>Great app called Application-4</description>
<publisher>Medio</publisher>
<category>Productivity</category>
<updated>01062001</updated>
<rating>4.0</rating>
<price>.99</price>
<currency>USD</currency>
<iconURI>http://medio.com</iconURI>
<downloadURI>http://medio.com</downloadURI>
<ns2:extensions>
<ns2:extension ns2:key="Sample">
<ns2:value>Extension</ns2:value>
</ns2:extension>
</ns2:extensions>
<ratingCount>35213614</ratingCount>
<downloadCount>12435854</downloadCount>
</ns2:recommendation>
in java 7, it is:
<ma:recommendation>
<id>3</id>
<type>ARTICLE</type>
<name>Application-3</name>
<description>Great app called Application-3</description>
<publisher>Medio</publisher>
<category>Productivity</category>
<updated>01062001</updated>
<rating>4.0</rating>
<price>.99</price>
<currency>USD</currency>
<iconURI>http://medio.com</iconURI>
<downloadURI>http://medio.com</downloadURI>
<_extensions>
<entry>
<key>Sample</key>
<value>Extension</value>
</entry>
</_extensions>
<ratingCount>35213614</ratingCount>
<downloadCount>12435854</downloadCount>
</ma:recommendation>
the difference is the extensions tag, which maps to a java code that doesn't change. anyone knows how to fix it?
java code for extensions:
#XmlRootElement(namespace = XMLNamespace.URL)
#XmlAccessorType(XmlAccessType.NONE)
#XmlType(namespace = XMLNamespace.URL)
public final class ExtensionMap extends HashMap<String, String> {
/** Serialized version unique identifier. */
private static final long serialVersionUID = -7235844731135521813L;
/**
* Default constructor to support JAXB binding.
*/
public ExtensionMap() {
super();
}
/**
* Default constructor to support JAXB binding.
* #param capacity The expected capacity of the map.
*/
public ExtensionMap(int capacity) {
super(capacity);
}
/**
* The list of wrapped Map entries that are structured for binding to XML
* with JAXB.
*
* #return The list of wrapped Map entries that are structured for binding
* to XML with JAXB.
*/
#XmlElement(name = "extension", namespace = XMLNamespace.URL, required = false)
#SuppressWarnings("unused")
private List<ExtensionMapElement> getEntries() {
return new ListAdapter();
}
/**
* The list of wrapped Map entries that are structured for binding to XML
* with JAXB.
*
* #param entries The list of wrapped Map entries that are structured for binding
* to XML with JAXB.
*/
#SuppressWarnings("unused")
private void setEntries(List<ExtensionMapElement> entries) {
if (entries != null) {
for (ExtensionMapElement entry : entries) {
put(entry.getKey(), entry.getValue());
}
}
}
/**
* Adapter for the list collection.
*
*/
private class ListAdapter implements List<ExtensionMapElement> {
#Override
public boolean add(ExtensionMapElement e) {
put(e.getKey(), e.getValue());
return true;
}
#Override
public void add(int index, ExtensionMapElement element) {
add(element);
}
#Override
public boolean addAll(Collection<? extends ExtensionMapElement> c) {
if (c != null) {
for (ExtensionMapElement element : c) {
add(element);
}
}
return true;
}
#Override
public boolean addAll(int index, Collection<? extends ExtensionMapElement> c) {
addAll(c);
return true;
}
#Override
public void clear() {
ExtensionMap.this.clear();
}
#Override
public boolean contains(Object o) {
throw new UnsupportedOperationException("Not supported yet.");
}
#Override
public boolean containsAll(Collection<?> c) {
throw new UnsupportedOperationException("Not supported yet.");
}
#Override
public ExtensionMapElement get(int index) {
throw new UnsupportedOperationException("Not supported yet.");
}
#Override
public int indexOf(Object o) {
throw new UnsupportedOperationException("Not supported yet.");
}
#Override
public boolean isEmpty() {
return ExtensionMap.this.isEmpty();
}
#Override
public Iterator<ExtensionMapElement> iterator() {
return new Iterator<ExtensionMapElement>() {
private Iterator<Map.Entry<String, String>> _iter = ExtensionMap.this.entrySet().iterator();
#Override
public boolean hasNext() {
return _iter.hasNext();
}
#Override
public ExtensionMapElement next() {
return new ExtensionMapElement(_iter.next());
}
#Override
public void remove() {
throw new UnsupportedOperationException("Not supported yet.");
}
};
}
#Override
public int lastIndexOf(Object o) {
throw new UnsupportedOperationException("Not supported yet.");
}
#Override
public ListIterator<ExtensionMapElement> listIterator() {
throw new UnsupportedOperationException("Not supported yet.");
}
#Override
public ListIterator<ExtensionMapElement> listIterator(int index) {
throw new UnsupportedOperationException("Not supported yet.");
}
#Override
public boolean remove(Object o) {
throw new UnsupportedOperationException("Not supported yet.");
}
#Override
public ExtensionMapElement remove(int index) {
throw new UnsupportedOperationException("Not supported yet.");
}
#Override
public boolean removeAll(Collection<?> c) {
throw new UnsupportedOperationException("Not supported yet.");
}
#Override
public boolean retainAll(Collection<?> c) {
throw new UnsupportedOperationException("Not supported yet.");
}
#Override
public ExtensionMapElement set(int index, ExtensionMapElement element) {
add(element);
return null;
}
#Override
public int size() {
return ExtensionMap.this.size();
}
#Override
public List<ExtensionMapElement> subList(int fromIndex, int toIndex) {
throw new UnsupportedOperationException("Not supported yet.");
}
#Override
public Object[] toArray() {
throw new UnsupportedOperationException("Not supported yet.");
}
#Override
public <T> T[] toArray(T[] a) {
throw new UnsupportedOperationException("Not supported yet.");
}
}
}
/**
* A utility type that wraps map entries to support a mapping between a
* {#link java.util.Map} interface and a class that can be bound to XML using
* JAXB.
*/
#XmlRootElement(namespace = XMLNamespace.URL)
#XmlAccessorType(XmlAccessType.FIELD)
#XmlType(namespace = XMLNamespace.URL)
final class ExtensionMapElement implements Serializable {
/**
* Serialized version unique identifier.
*/
private static final long serialVersionUID = 8211130122512683829L;
/**
* The key of the wrapped map entry.
*/
#XmlAttribute(name = "key", namespace = XMLNamespace.URL, required = true)
private String _key;
/**
* The value of the wrapped map entry.
*/
#XmlElement(name = "value", namespace = XMLNamespace.URL, required = true)
private String _value;
/**
* Default constructor to support JAXB Binding.
*/
public ExtensionMapElement() {
}
/**
* Wraps a map entry with an instance of this class.
*
* #param e
* The map entry to wrap.
*/
public ExtensionMapElement(Map.Entry<String, String> e) {
_key = e.getKey();
_value = e.getValue();
}
/**
* The key of the wrapped map entry.
*
* #return The key of the wrapped map entry.
*/
public String getKey() {
return _key;
}
/**
* The value of the wrapped map entry.
*
* #return The value of the wrapped map entry.
*/
public String getValue() {
return _value;
}
}

Answer 1

Use
public final class ExtensionMap {
private Map<String, String> holder = new HashMap<String, String>();
public String put(String key, String value)
{
return holder.put(key, value);
}
// ...
instead of extanding HashMap.
Java 6 uses
public List<ExtensionMapElement> getEntries()
to get entries, but Java 7 ignore this method becouse you class extends HashMap