NPE setting properties with CustomEvent

Question

Hello, I am trying out CustomEvents, but there is something strange setting properties. I try to do a
public class CustomEvents extends VBean {
   private ID myEvent = ID.registerProperty("MY_EVENT");
   private ID myData = ID.registerProperty("MY_DATA");
   private IHandler handler = null;
   private void log(String message) {
      System.out.println(message);
   public CustomEvents() {
      log("Constructor");
   public final void init(IHandler handler) {  
      this.handler = handler;
      super.init(handler);
      log("Init");
      try {
         CustomEvent customEvent = new CustomEvent(handler, myEvent);
         if ( (myEvent == null) || (myData == null) || (handler == null) || (customEvent == null) ) {
            log("There be nulls");
         handler.setProperty(myData, "hep");
         dispatchCustomEvent(customEvent);
      } catch (Exception e) {
         e.printStackTrace();
      log("done");
}but end up with an
Constructor
Init
java.lang.NullPointerException
     at oracle.forms.handler.JavaContainer.setProperty(Unknown Source)
     at fi.affecto.webmarela.forms.CustomEvents.init(CustomEvents.java:31)
     at oracle.forms.handler.UICommon.instantiate(UICommon.java:2984)
     at oracle.forms.handler.UICommon.onCreate(UICommon.java:1040)
     at oracle.forms.handler.JavaContainer.onCreate(Unknown Source)
     at oracle.forms.engine.Runform.onCreateHandler(Runform.java:2254)
     at oracle.forms.engine.Runform.processMessage(Runform.java:3347)
     at oracle.forms.engine.Runform.processSet(Runform.java:3491)
     at oracle.forms.engine.Runform.onMessageReal(Runform.java:3099)
     at oracle.forms.engine.Runform.onMessage(Runform.java:2857)
     at oracle.forms.engine.Runform.sendInitialMessage(Runform.java:5635)
     at oracle.forms.engine.Runform.startRunform(Runform.java:1207)
     at oracle.forms.engine.Main.createRunform(Unknown Source)
     at oracle.forms.engine.Main.start(Unknown Source)
     at sun.applet.AppletPanel.run(Unknown Source)
     at java.lang.Thread.run(Unknown Source)
done
*/any suggestions? myData is not null but has it failed to hook on to something during initialization? I decompiled JavaContainer and it only has null checks for top-level incoming parameters and the stack trace doesn't give any more detail. Or am I misunderstanding the usage of Custom Events completely?
Thankful for help,
-Nik

Answer 1

Nicklas,
the problem is that Forms does not have a property
handler.setProperty(myData, "hep");
You need to override
public boolean setProperty(ID ID, Object object)
in your Java implementation. Then within this method you evaluate if the ID is "myData" and if, do something. If no ID match can be found then you call
return super.setProperty(_ID, _object);
Thsi way all custom properties are handled by you and all Forms properties are passed to Forms.
Frank