ListSelect in Form help

Hello all,

I am using a Form; here is the field factory:

private class MyFieldFactory extends DefaultFieldFactory
	{

		private ListSelect ls;

		public MyFieldFactory()
		{
			super();
			ls = new ListSelect("Included Stuff : ");
			ArrayList<Stuff> possible = new ArrayList<Stuff>(getStuffList());
			possible.remove(item);
			if (possible.size() > 0)
			{
				ls.setContainerDataSource(new BeanItemContainer(possible));
			}
		}

		@Override
		public Field createField(Item myItem, Object propertyId, Component uiContext)
		{
			if("includedStuff".equals(propertyId))
			{
				return ls;
			}

			Field f = super.createField(myItem, propertyId, uiContext);
			if ("name".equals(propertyId))
			{
				TextField tf = (TextField) f;
				tf.setRequired(true);
				tf.setCaption("Name : ");
				tf.setRequiredError("Enter a stuff name.");
				tf.addValidator(new StringLengthValidator("Name must be at least 3 characters, no more than 255.", 3, 255, false));
			}

			return f;
		}
	}

I have an "Add / Edit" button to go with this. If I remove the ListSelect, the Form works as expected. With the ListSelect, when I click the "Add / Edit" button, I get this StackTrace:

com.vaadin.data.Property$ConversionException: java.lang.NoSuchMethodException: support.OrderedArrayList.(java.lang.String)
	at com.vaadin.data.util.MethodProperty.setValue(MethodProperty.java:709)
	at com.vaadin.ui.AbstractField.commit(AbstractField.java:226)
	at com.vaadin.ui.Form.commit(Form.java:312)
	at com.flphsys.vaadin.CallRoutesLayout$2.buttonClick(CallRoutesLayout.java:100)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at com.vaadin.event.ListenerMethod.receiveEvent(ListenerMethod.java:487)
	at com.vaadin.event.EventRouter.fireEvent(EventRouter.java:161)
	at com.vaadin.ui.AbstractComponent.fireEvent(AbstractComponent.java:1107)
	at com.vaadin.ui.Button.fireClick(Button.java:341)
	at com.vaadin.ui.Button.changeVariables(Button.java:177)
	at com.vaadin.terminal.gwt.server.AbstractCommunicationManager.handleVariables(AbstractCommunicationManager.java:1060)
	at com.vaadin.terminal.gwt.server.AbstractCommunicationManager.doHandleUidlRequest(AbstractCommunicationManager.java:561)
	at com.vaadin.terminal.gwt.server.CommunicationManager.handleUidlRequest(CommunicationManager.java:260)
	at com.vaadin.terminal.gwt.server.AbstractApplicationServlet.service(AbstractApplicationServlet.java:438)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at org.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:390)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
	at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:849)
	at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
	at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:454)
	at java.lang.Thread.run(Thread.java:619)

OrderedArrayList is simply a wrapper around ArrayList that inserts items in Alphabetical order.

What am I doing wrong?

I'm a vaadin newbie, so take my answer with that in mind... I've not used ListSelect before, but I have used TwinColSelect and found that my bean needed to get/set a Set, not an array (not sure about a List). If that's the case, then your bean should have methods like:

public Set<Stuff> getStuff() {...}
public void setStuff(Set<Stuff> s) {...}

Or if it does support lists, they may need to be the more generic List<Set> used in the get/set rather than ArrayList. Good luck!

David,

You were right! And in my experimentation, for the TwinColSelect (I love it) and the ListSelect to work, your getters need to return a Set<> and your setters need to take a Set<>. No extensions on Set - i.e. HashSet won't work in getter or setter.

I wonder why it is coupled so tightly with a Set instead more loosley with a Collection....

Probably because a Set has no repetitions and makes no promises on ordering. So it feels like the right contract.