An idea is to wrap the Properties object in a class of your own
implementing Map as follows:
class MyProps implements Map<String, String> {
Properties props;
public void put(String key, String value) {
if (value == null) props.remove(key);
else props.put(key, value);
}
This does sound like a bug in PropertyResolver as it should probably test
whether the Map is a Hashtable and call remove() since Hashtable is
documented to throw an NPE when put() is called with a null value.
On Fri, Oct 18, 2013 at 1:55 PM, Andy Van Den Heuvel <
andy.vandenheu...@gmail.com> wrote:
> Hey,
>
> I'm trying to create a form with a CompoundPropertyModel to fill a
> java.util.Properties object dynamically.
>
> Form<Properties> form = new Form<>("form", new
> CompoundPropertyModel<>(properties));
> form.add(new TextField<String>("host"));
> form.add(new TextField<String>("port"));
>
> This works correct when I start from an empty java.util.Properties object.
> If I have an existing java.util.Properties object (with filled data)
> and I remove the value in the html page, I want the key-value pair to be
> deleted from the Properties object.
>
> With my current implementation I get a stacktrace (because it tries to
> write a null value in the java.util.Properties object)
>
> java.lang.NullPointerException
> at java.util.Hashtable.put(Hashtable.java:432)
> at
>
> org.apache.wicket.core.util.lang.PropertyResolver$MapGetSet.setValue(PropertyResolver.java:803)
> at
>
> org.apache.wicket.core.util.lang.PropertyResolver$ObjectAndGetSetter.setValue(PropertyResolver.java:644)
> at
>
> org.apache.wicket.core.util.lang.PropertyResolver.setValue(PropertyResolver.java:144)
>
>
> Has anybody have an idea how best to create this behaviour?
> Thanks in advance for your help!
>
