F:selectitems problem with Faces message

Question

Hi,
i have a JSF page which has f:selectitems tag which IS BINDED to the managed bean as mentioned below
<af:selectOneChoice label="snapshot"
required="true" value="#{SMB.environment}"
requiredMessageDetail="Select an Environment to Create Snapshot"
valueChangeListener="#{SMB.environmentSelect}"
autoSubmit="true" id="environment"
binding="#{SMB.environment_Binding}">
<f:selectItems value="#{EM.environmentNames}"/>
</af:selectOneChoice>
Managed bean bound to environmentsnames is as follows
public ArrayList getEnvironmentNames() {
ModelHandler mh = ModelHandler.getInstance();
ArrayList environmentNames = new ArrayList();
try{
List envlist = mh.getEnvironments();//this may throw exception as it connects to database and do some processing
for (int i = 0, size = envlist.size() ; i < size; i++) {
EnvironmentVO en = (EnvironmentVO)envlist.get(i);
environmentNames.add(new SelectItem(en.getEnvironmentName()));
}catch(Exception e){
FacesMessage facesMsg =new FacesMessage(FacesMessage.SEVERITY_ERROR,"",e.getMessage());
FacesContext.getCurrentInstance().addMessage(null, facesMsg);
return environmentNames;
whenever exception is thrown list is shown empty and no Error messages are displayed even though messages are added to the Facesmessages. when i refresh the page by clicking some other button.it is showing properly.
do i miss something here?
is this the best way to do it[connecting to database e.t.c]
regards,
Harsha

Answer 1

yes ,what you said is true i have included theh:messages JSF code. whenever exception occurs in ModelHandler i am using the FacesMessage to store the exception .
but these messages are not displayed on the screen immediately. but when i refresh the page i am able to see the error message.
say for example
i have selected one combo box which shows no of employees based on company name
say
1. i have selected microsoft
it displays 1xxxx //no database error
2. i have selected ibm
it displays nothing//because of exception . but it doesn't show the exception in UI eventhough i catched the exception and put the exception in FacesMessage [i figure out that exception is thrown using debugger tool].
3. i have selected oracle
it displays 1xxxxxx . UI shows the exception catched before[exception in ibm   selected ].
can you please help me on this issue