How to marshal map to xml without tag value

I have a HashMap which I want to convert to XML:

@XmlJavaTypeAdapter(OrdersAdapter.class)
private Map<Long, Order> orders = new LinkedHashMap<Long, Order>();

By default map is converted to <entry><key></key><value></value><entry>, but I wanted to get XML, where key is attribute and there is no value tag. Something like this:

<?xml version="1.0" encoding="UTF-16" standalone="yes"?>
<productsMap>
    <orders>
        <order orderId="1">
           <prodId>123</prodId>
           <price>1</price>
        </order>
        <order orderId="2">
           <prodId>15</prodId>
           <price>10</price>
        </order>
    </orders>
</productsMap>

Using my program from github: http://ift.tt/1uFCzhu , now I am able to generate xml like this:

<?xml version="1.0" encoding="UTF-16" standalone="yes"?>
<productsMap>
    <orders>
        <order orderId="1">
            <value>
                <prodId>123</prodId>
                <price>1</price>
            </value>
        </order>
        <order orderId="2">
            <value>
                <prodId>15</prodId>
                <price>10</price>
            </value>
        </order>
    </orders>
</productsMap>

Do you know how to avoid "value" tag?