org.omnifaces.util

Class Exceptions

java.lang.Object

org.omnifaces.util.Exceptions

public final class Exceptions
extends Object

Collection of general utility methods with respect to working with exceptions. So far there's only an unwrapper and a type checker.

Usage

Some examples:

 // Check if the caught exception has a ConstraintViolationException in its hierarchy.
 catch (PersistenceException e) {
     if (Exceptions.is(e, ConstraintViolationException.class)) {
         // ...
     }
 }
 

 // Unwrap the caught FacesException until a non-FacesException is found.
 catch (FacesException e) {
     Exception realRootCause = Exceptions.unwrap(e, FacesException.class);
     // ...
 }
 

Author:

Bauke Scholtz

Method Summary

Modifier and Type	Method and Description
static <T extends Throwable> boolean	is(Throwable exception, Class<T> type) Returns true if the given exception or one of its nested causes is an instance of the given type.
static Throwable	unwrap(Throwable exception) Unwrap the nested causes of given exception as long as until it is not an instance of FacesException (Mojarra) or ELException (MyFaces) and then return it.
static <T extends Throwable> Throwable	unwrap(Throwable exception, Class<T> type) Unwrap the nested causes of given exception as long as until it is not an instance of the given type and then return it.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

unwrap

public static <T extends Throwable> Throwable unwrap(Throwable exception,
                                                     Class<T> type)

Unwrap the nested causes of given exception as long as until it is not an instance of the given type and then return it. If the given exception is already not an instance of the given type, then it will directly be returned. Or if the exception, unwrapped or not, does not have a nested cause anymore, then it will be returned. This is particularly useful if you want to unwrap the real root cause out of a nested hierarchy of ServletException or FacesException.

Type Parameters:

T - The generic throwable type.

Parameters:

exception - The exception to be unwrapped.

type - The type which needs to be unwrapped.

Returns:

The unwrapped root cause.

unwrap

public static Throwable unwrap(Throwable exception)

Unwrap the nested causes of given exception as long as until it is not an instance of FacesException (Mojarra) or ELException (MyFaces) and then return it. If the given exception is already not an instance of the mentioned types, then it will directly be returned. Or if the exception, unwrapped or not, does not have a nested cause anymore, then it will be returned.

Parameters:

exception - The exception to be unwrapped from FacesException and ELException.

Returns:

The unwrapped root cause.

Since:

1.4

is

public static <T extends Throwable> boolean is(Throwable exception,
                                               Class<T> type)

Returns true if the given exception or one of its nested causes is an instance of the given type.

Type Parameters:

T - The generic throwable type.

Parameters:

exception - The exception to be checked.

type - The type to be compared to.

Returns:

true if the given exception or one of its nested causes is an instance of the given type.