How to unchecked all choices as default of select one radio button in JSF?

Question

I have the following JSF radio button:

<h:selectOneRadio id="journeyDir"
  value="#{refParam.journeyDir}">
  <f:selectItems value="#{newMessage.journeyDirectionSelectItemList}" />    
</h:selectOneRadio>

The values of the radio button, which can be selected by the user was defined in this Java method:

public List<SelectItem> getJourneyDirectionSelectItemList() {
    final List<SelectItem> journeyDirectionSelectItemList = new ArrayList<SelectItem>();

    journeyDirectionSelectItemList.add(new SelectItem(Journey.BIDIRECTION,
            YES));
    journeyDirectionSelectItemList.add(new SelectItem(Journey.ONEWAY, NO));

    return journeyDirectionSelectItemList;
}

Now I have the problem, that the first value of the radio button, which was declared in the Java method above, will be selected automatically by load the JSF webpage. I have the requirement, that no values must be selected automatically by the system.

How can I solve this problem? Any ideas? I use JSF 1.2.

Answer 1

只要确保将您的journeyDir变量设置为null

Answer 2

Just try that code in yourController.java

@PostConstruct
public void postConstruct() {    
// ....    

// initialize journeyDir by setting its default value
// Note you must write ONLY one of next lines
refParam.journeyDir = null; // if you need to unchecked all choices
refParam.journeyDir = YES; // if you need to checked first choice
refParam.journeyDir = NO; // if you need to checked second choice  

// ....
}  

Note : you must take care that
There is no other code in your controller change its default value later
Until the screen page loaded for the first time