Question

An Id is passing in as a Url parameter. I try to make sure that the id is an number. If not redirect to the main page

if(facilityId != null){
    try{
        Long.parseLong(facilityId);
    }catch(NumberFormatException e){
        try {
            FacesContext.getCurrentInstance().getExternalContext().redirect("DisplayList.jsf");                    
        } catch (IOException ex) {}
    }
    facility = documentSBean.findFacilityById(Long.parseLong(facilityId));
    ...
}

so if I pass in an id like this

www....?facilityId=3?sdfasfda

I catch that 3?sdfasfda is not a number, and get to the redirect statement, but it does not redirect right a way, it execute the next couple lines which try to convert 3?sdfasfda to a Long, hence yield NumberFormatException. So is there a way to force redirect right away, or is there some other way to solve this problem. Wish that there is an else after a catch 😀 :D. The above codes are inside my @PostConstruct init() method

Answer 1

Yes, simply return from the method:

FacesContext.getCurrentInstance()
   .getExternalContext().redirect("DisplayList.jsf");
return;

When you invoke redirect(..) the only thing that happens is that a special header (Location) is set in the response object. But the flow of the invoking method continues, unless you return from it after you call redirect.