Struts 2 - How to convert object list to string? - collections

Question

I'm learning Struts 2 and stucking on converting a list of object to string.
I have class Movie which has a list of Genre (List<Genre>) as its property. I want to show genre names of a movie as a string (each genre is separated by a comma). I have converted other classes to String successfully but none of them are arrays or collections.
My first attempt was writing a custom converter class with method convertToString(Map map, Object obj) but it didn't work:
if (obj instanceof List) {
System.out.println("Found a list!");
StringBuilder results = null;
List list = (List) obj;
if (list != null && list.size() > 0) {
results = new StringBuilder();
// Genre List
if (list.get(0) instanceof Genre) {
System.out.println("Found a genre list!");
for (Object genre : list) {
results.append(((Genre) genre).getName() + ", ");
}
}
}
On JSP page:
<s:iterator value="movieList" status="movieStatus">
...
<td>
<s:property value="genres" />
</td>
...
</s:iterator>
Then I tried another way:
if (obj instanceof Genre) {
System.out.println("Found a genre!");
return ((Genre) obj).getName();
}
JSP:
<td>
<s:iterator value="genres" status="genreStatus">
<s:text name="genres[#genreStatus.index]" />,
</s:iterator>
</td>
or just this without converter:
<td>
<s:iterator value="genres" status="genreStatus">
<s:text name="genres[#genreStatus.index].name" />,
</s:iterator>
</td>
And it didn't work either.
In both cases, Struts didn't jump into any if clauses or report any errors (dev mode was on). It just showed Genre objects' memory addresses (the first case) or "genres[#genreStatus.index].name" (the second) on the browser.
What did I miss here? Any responses would be appreciated!

Answer 1

You don't need converter for that neither <s:iterator> tag. Just use OGNL projections.
<s:property value="genres.{name}" />