@ManagedProperty(value = “#{param.id}”) in a non-request Scope Bean

Question

I need to pass a parameter (POST) to a @managedBean, I used managed properties like this:

@ManagedProperty(value = \"#{param.id}\")
private int id;
         


        

Answer 1

Two ways:

1. Make the bean request scoped and inject the view scoped one as another @ManagedProperty.

   @ManagedBean
   @RequestScoped
   public class RequestBean {
   
       @ManagedProperty(value="#{param.id}")
       private Integer id;
   
       @ManagedProperty(value="#{viewBean}")
       private ViewBean viewBean;
   }
   

   The view scoped bean is available during @PostConstruct and action methods of request scoped bean. You only need to keep in mind that the id can get lost when you do a postback to the same view without the parameter.

2. Or, grab it manually from the request parameter map during bean's initialization.

   @ManagedBean
   @ViewScoped
   public class ViewBean {
   
       private Integer id;
   
       @PostConstruct
       public void init() {
           id = Integer.valueOf(FacesContext.getCurrentInstance().getExternalContext().getRequestParameterMap().get("id"));       
       }
   }
   

   This way the initial id is available during the entire view scope.