Aliasing contents of a Set using XStream

Question

I have a problem with aliasing in XStream.

I've got a set of String items that I would like to serialize to XML like this:

<types>
  <type>abc</type>
  <type>def</type>
</types>

However, I can't seem to find a good way to solve this. I've tried a list of strings, but then I end up with

<types>
  <string>abc</string>
  <string>def</string>
</types>

I've also tried putting the String in a simple class, but then I get

<types>
  <type>
    <aType>abc</aType>
  </type>
</types>

where <type> is the alias of the custom class, and aType is the attribute in the class, i.e I get one level too much using this approach. How would I go about eliminating the extra level or simply substituting the <string> with a custom tag name?

Answer 1

You will need to alias both the List and the items in the list.

List<String> types = new ArrayList<String>();
types.add("abc");
types.add("def");

XStream xstream = new XStream();
xstream.alias("types", List.class);
xstream.alias("type", String.class);
System.out.println(xstream.toXML(types));

Will result in

<types>
  <type>abc</type>
  <type>def</type>
</types>