Is it possible to test for enum equality in JSF?
E.g. where stuff
is an enum Stuff
:
<h:outputText value="text" rendered="#{mrBean.stuff == mrsBean.stuff}"/>
Because there is only one instance of each enum constant, it is permissible to use the == operator in place of the equals method when comparing two object references if it is known that at least one of them refers to an enum constant.
equals method uses == operator internally to check if two enum are equal. This means, You can compare Enum using both == and equals method.
This is actually more EL related than JSF related. The construct as you posted is valid, but you should keep in mind that enum values are in EL 2.1 are actually evaluated as String
values. If String.valueOf(mrBean.getStuff())
equals String.valueOf(mrsBean.getStuff())
, then your code example will render. In EL 2.2 the same construct will work, but they are evaluated as true enums.
Note that it indeed requires a getter method to return the enum value. Given the fact that enums are treated as String
, you can in essence also just do:
<h:outputText value="text" rendered="#{mrBean.stuff == 'FOO'}" />
In current EL 2.2 version, you cannot access enum values directly like this:
<h:outputText value="text" rendered="#{mrBean.stuff == Stuff.FOO}" />
This is only possible when you use OmniFaces <o:importConstants>
:
<o:importConstants type="com.example.Stuff" /> ... <h:outputText value="text" rendered="#{mrBean.stuff == Stuff.FOO}" />
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