Problems setting managed bean property of type Integer

Question

I got a problem when I use valueBinding #{param.productId} in faces-config.xml for my managed bean:
My property 'productId' in bean Product is of type Integer, and my bean is in request scope. When I try to invoke some action on page, wich should navigate me to another view - JSF is trying to set productId for current view, and of course it is empty (""), and for the reasons given above I'm getting an error:
javax.faces.FacesException: Can't set managed bean property: 'applicationId'.
at com.sun.faces.config.ManagedBeanFactory.setPropertiesIntoBean(ManagedBeanFactory.java:576)
at com.sun.faces.config.ManagedBeanFactory.newInstance(ManagedBeanFactory.java:233)
at com.sun.faces.application.ApplicationAssociate.createAndMaybeStoreManagedBeans(ApplicationAssociate.java:256)
... 60 more
Caused by: java.lang.NumberFormatException: For input string: ""
at java.lang.NumberFormatException.forInputString(NumberFormatException.java:48)
at java.lang.Integer.parseInt(Integer.java:489)
at java.lang.Integer.<init>(Integer.java:609)
at com.sun.faces.config.ManagedBeanFactory.getConvertedValueConsideringPrimitives(ManagedBeanFactory.java:855)
at com.sun.faces.config.ManagedBeanFactory.setPropertiesIntoBean(ManagedBeanFactory.java:555)
Should I use requestScope instead of param to have my parameter null, and not "" ?
If so, how should I pass requestScope parameter using commandLink?

Answer 1

Hi! I have a problem with setting params too. Probably my one is different.
I have a jsp page which show a datatable, where I can see a row for each Product. If I click on its name I would navigate to another page that shows product informations, as several ecommerce sites do.
But I can't understand what and how I must set to inform the details page on which product have to show.
I read in this forum that it's possible to set a parameter in productBean, and then the constructor of product bean loads others fields knowing its id.
The snippet of my faces-config.xml is:
  <managed-bean>
    <managed-bean-name>product</managed-bean-name>
    <managed-bean-class>test.backing.ProductBean</managed-bean-class>
    <managed-bean-scope>request</managed-bean-scope>
    <managed-property>
      <property-name>idToLoad</property-name>
      <property-class>java.lang.Integer</property-class>
      <value>#{param.id}</value>
    </managed-property>
  </managed-bean>It is possible? is a correct solution? and if it is, how can I do that?
Thanks very much if someone can resolve my problem.
Claudio.