PropertyEditor issue with Set type - propertyeditor

Question

Using: Spring 3.2 portlet MVC with Liferay 5.2.3 and Tomcat 6.0.18
I'm trying to create a PropertyEditor to convert between Set<Type> and String, and back again. I have successfully got Set<Type> to String to work without problems. But I can't get property editor to be recognized for the reverse direction. I've done this successfully with Type -> String -> Type, but doing the conversion for a Set is eluding me.
I have determined that the SetAsText method is never invoked, and I get a runtime error that shows that the conversion wasn't done. Information about propertyEditors is very sparse, and with one or two exceptions the only vaguely related issues I could find are 4 or more years old.
Either I'm missing something so fundamental that I can't see it, or it's something deeper in the framework, but I would be grateful for any help or suggestions.
Here's the #InitBinder snippet from my controller:
#InitBinder("formBacking")
public void initBinder(WebDataBinder binder){
binder.registerCustomEditor(Set.class, "field", new SetEditor(listService, Set.class));
logger.info("FormBacking Binder initialization");
}
Here's my PropertyEditor:
public class SetEditor extends PropertyEditorSupport {
protected static Logger logger = Logger.getLogger("PropertyEditor");
private ListService listService;
public SetEditor(ListService listService, Class clazz) {
super(clazz);
this.listService = listService;
}
#Override
public String getAsText() {
Stack<String> returnString = new Stack<String>();
Set<Type> types = new HashSet<Type>();
try {
types = (Set<Type>)this.getValue();
for (Type type:types) {
returnString.push(type.getTypeId().toString());
}
} catch (NullPointerException e) {
logger.info("getAsText is \"\"");
return "";
} catch (Exception e) {
logger.info("getAsText Other Exception: " + e.getMessage());
return "";
}
return "[" + StringUtils.collectionToDelimitedString(returnString,",") + "]"; // a very useful Spring Util
}
#Override
public void setAsText(String text) throws IllegalArgumentException {
Type type = new Type();
Set<Type> result = new HashSet<Type>();
try {
String[] typeArray = text.split("[,]"); //this may not be correct, but I can't get here to debug it!!
for(String type:typeArray) {
if(!type.isEmpty()) {
type = listService.getType(Long.valueOf(text));
result.add(type);
}
}
}catch(NullPointerException e) {
logger.info("SetAsText is \"\" ");
setValue(null);
}
catch(Exception e) {
logger.info("setAsText Other Exception: " + e.getMessage());
}
setValue(result);
}
}
the Type class snippet is:
#Entity(name="Type")
#Table(name="type")
public class Type {
#ManyToMany(fetch = FetchType.EAGER)
#JoinTable(name = "playListImages",
joinColumns={#JoinColumn(name="superTypeId")},
inverseJoinColumns={#JoinColumn(name="typeId")})
private Set<Type> types = new HashSet<Type>();
getters and setters...

Answer 1

Hopefully this will help any one else who has struggled to resolve this issue.
After a bit of further investigation (i.e. turning on Trace logging), it appears that Spring Annotations doesn't fully register PropertyEditors that are associated with Set (maybe Collections in general, although I haven't verified that). Trace showed the built-in CustomCollectionEditor being invoked (but only on String -> Type conversions), even though I had registered my own editor.
This, imho, is a Spring Annotations bug. The work around, which fully works as I expected, is to create your own property editor registrar and register the property editor in the xxx-portlet.xml configuration file.
For example: project-portlet.xml should include something along these lines:
<bean class="org.springframework.web.portlet.mvc.annotation.AnnotationMethodHandlerAdapter">
<property name="webBindingInitializer">
<bean class="org.springframework.web.bind.support.ConfigurableWebBindingInitializer">
<property name="propertyEditorRegistrars">
<list>
<ref bean="myPropertyEditorRegistrar" />
</list>
</property>
</bean>
</property>
</bean>
<bean id="myPropertyEditorRegistrar"
class="com.sbeko.slider.util.MyPropertyEditorRegistrar" />
Registration class:
public class MyPropertyEditorRegistrar implements PropertyEditorRegistrar {
public void registerCustomEditors(PropertyEditorRegistry registry)
{registry.registerCustomEditor(Set.class, new TypeEditor(Set.class));
}