Question

After upgrading to JSF2 (probably) one special accessor in an .xhtml file generates IllegalArgumentExceptions but I can’t really find out why. Running the app on my local JBoss (4.2.2) does not generate this exception but this can be related to a difference between debug and live data.

Following stack trace is generated that I could extract from the production server log:

Caused by: javax.el.ELException: /xy/xy-subtemplate1.xhtml @131,45 value="#{someClass.someProperty}": java.lang.IllegalArgumentException
    at com.sun.facelets.el.TagValueExpression.setValue(TagValueExpression.java:101)
    at javax.faces.component.UIInput.updateModel(UIInput.java:818)
    ... 36 more
Caused by: java.lang.IllegalArgumentException
    at sun.reflect.GeneratedMethodAccessor1134.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at javax.el.BeanELResolver.setValue(BeanELResolver.java:108)
    at com.sun.faces.el.DemuxCompositeELResolver._setValue(DemuxCompositeELResolver.java:255)
    at com.sun.faces.el.DemuxCompositeELResolver.setValue(DemuxCompositeELResolver.java:281)
    at org.apache.el.parser.AstValue.setValue(AstValue.java:114)
    at org.apache.el.ValueExpressionImpl.setValue(ValueExpressionImpl.java:249)
    at com.sun.facelets.el.TagValueExpression.setValue(TagValueExpression.java:93)
    ... 37 more

someClass is being iterated over in a list and has the following methods to access someProperty:

public int getSomeProperty() {
    return this.getSomeRelatedEnum().ordinal();
}

public void setSomeProperty( final int index) {
    this.setSomeRelatedEnum( SomeRelatedEnum.fromOrdinal( index) );
}

How can this lead to the IllegalArgumentException mentioned above?

Answer 1

That can happen when the setter method after all expects a different argument type than the one which is provided from EL on.

I guess that it’s related to the fact that hardcoded/unconverted numbers in EL are by default treated as long and not as int. Try either changing the int to be long, or providing an explicit integer converter on the input component like so <h:someInput converter="javax.faces.Integer">.

By the way, why don’t you just get/set the enum itself directly? Getting/setting the enum by its ordinal is whacky.