[OmniFaces utilities (2.1/2.0)] Check if an exception or one of its nested causes is an instance of the given type

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[OmniFaces utilities] The is() method returns true if the given exception or one of its nested causes is an instance of the given type.

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Method:

OmniFaces 2.1 implementation:

OmniFaces 2.0 implementation:

Usage:

Example 1 - this is copy-pasted from OmniFaces documentation (check if the ConstraintViolationException is the cause of PersistenceException)

try{

   ... 

   } catch (PersistenceException e) {

     // Check if the caught exception has a ConstraintViolationException in its hierarchy.

     if (Exceptions.is(e, ConstraintViolationException.class)) {   

         // ...

     }

   }

Example 2 - distinguish between NullPointerException and IllegalArgumentException

try {

    //... code that may produce other exceptions than NullPointerException and IllegalArgumentException

    // if the 'myform' component is not found then next line will throw a NullPointerException

    UIForm myform = (UIForm) Faces.getViewRoot().findComponent("myForm");

    // if the 'myform' component contains children then next line will throw an IllegalArgumentException

    Components.validateHasNoChildren(myform);

    //... more code that may produce other exceptions than NullPointerException and IllegalArgumentException

    } catch (Exception e) {

      if (Exceptions.is(e, java.lang.NullPointerException.class)) {

          LOG.info("The form 'myFrom' cannot be found !");

      } else if (Exceptions.is(e, java.lang.IllegalArgumentException.class)) {

          LOG.log(Level.INFO, "]" + "The form ''myFrom'' was found, but it has childrens ! [{0}", e.getMessage());

      }

    }

Example 3 - in a custom exception handler for conditional navigation

...

Throwable throwable = exceptionQueuedEventContext.getException();

FacesContext facesContext = FacesContext.getCurrentInstance();

NavigationHandler nav = facesContext.getApplication().getNavigationHandler();

if (Exceptions.is(throwable, javax.faces.convert.ConverterException.class)) {

    //redirect to converters error page, converter.xhtml                                       

    nav.handleNavigation(facesContext, null, "/converter");

}

if (Exceptions.is(throwable, javax.faces.validator.ValidatorException.class)) {

    //redirect to validators error page, validator.xhtml

    nav.handleNavigation(facesContext, null, "/validator");

}

facesContext.renderResponse();

...

Obviously, you may found many useful examples for this method.

API 2.1 GH 2.1
API 2.0 GH 2.0