30 Sept 2017

Right getters for "Boolean" and "boolean" values

In this post I would like to highlight a small pitfall that sometimes spoils ADF/JSF developers lives.  It happens when an EL expression on a page is referring to a boolean property of a managed bean or an object and a getter for this property is declared in a wrong way. This leads to either PropertyNotFound or  PropertyNotReadable exceptions.

Let's consider a simple example. There is a managed bean with the following methods:

  public boolean isPrimitiveValue()
    return true;

  public Boolean isObjectValue()
    return Boolean.TRUE;

There is a page with a couple of buttons referring to the he managed bean:

 <af:button text="button 1" id="b1" rendered="#{theBean.primitiveValue}"/>
 <af:button text="button 2" id="b2" rendered="#{theBean.objectValue}"/>

It works well for the first button, but it doesn't for the second one raising a PropertyNotFound exception like "...The class 'com.cs.adfpractice.view.TheBean' does not have the property 'objectValue'...".

The thing is that the EL engine can't resolve a getter starting with "is" for the Boolean type returning an object. It works only for the primitive boolean type.

If we change the second getter like this:

  public Boolean getObjectValue()
    return Boolean.TRUE;

It will work perfect.

That's it!

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