From: ginger <ggtech888_at_gmail.com>
Date: Wed, 23 Mar 2011 18:20:20 -0400

Hello, JAXB Gurus,

We are using RESTEasy to implement RESTful APIs, which employs JAXB for
its marshal/unmarshal job. What we have found very inconvenient is the
fact that we can only define default namespace once for the whole
document marshalled, rather than defining it locally for every root
element that we have a namespace URI.

Eg, what we want is like the following

<Aroot xmlns="http://www.w3.org/2005/A">
<Achild....>
<Broot xmlns="http://www.w3.org/2005/B">
<Bchild....>
         ...
</Bchild>
</Achild>
</Aroot>

so there are 2 levels of default namespace, when it is within A's child
elements, the default namespace is A; and when it steps into B's child
element, it is B

But JAXB (2.1.9) gives sth like

<ANS:Aroot xmlns:ANS="http://www.w3.org/2005/A">
<ANS:Achild....>
<Broot>
<Bchild....>
         ...
</Bchild>
</ANS:Achild>
</ANS:Aroot>

therefore only B's namespace is recognized as the default and used from
start to end. We do extend NamespacePrefixMapper and set it in the
marshaller used as following:

NamespacePrefixMapper mapper = new NamespacePrefixMapper()
{
     public String getPreferredPrefix(String namespace, String s1,
boolean b)
     {
         if (namespace.equals("http://www.w3.org/2005/A")) return "ANS";
         else return s1;
     }
};

marshaller.setProperty("com.sun.xml.bind.namespacePrefixMapper", mapper);

If we replace
     return "ANS"
with
     return "";

then A's child elements are preceeded with ns1, as people have commented
online. Is it do-able with JAXB 2.19 to achieve what we want?

Thanks a million for your kind helps in advance

gigi