/*
Copyright (C) SYSTAP, LLC DBA Blazegraph 2006-2016. All rights reserved.
Contact:
SYSTAP, LLC DBA Blazegraph
2501 Calvert ST NW #106
Washington, DC 20008
licenses@blazegraph.com
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
* Created on Feb 27, 2008
*/
package com.bigdata.util;
/**
* Utility class declaring methods for examining a stack trace for an instance
* of some class of exception.
*
* @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan Thompson</a>
* @version $Id$
*/
public class InnerCause {
/**
* Examines a stack trace for an instance of the specified cause nested to
* any level within that stack trace.
*
* @param t
* The stack trace.
* @param cls
* The class of exception that you are looking for in the stack
* trace.
*
* @return An exception that is an instance of that class iff one exists in
* the stack trace and <code>null</code> otherwise.
*
* @throws IllegalArgumentException
* if any parameter is null.
*/
// static public Throwable getInnerCause(Throwable t, Class cls) {
static public Throwable getInnerCause(Throwable t,
final Class<? extends Throwable> cls) {
if (t == null)
throw new IllegalArgumentException();
if (cls == null)
throw new IllegalArgumentException();
{
Class x = t.getClass();
// Check for Iterable<Throwable>
if(Iterable.class.isAssignableFrom(x)) {
for (Object o : (Iterable) t) {
if (!(o instanceof Throwable)) {
continue;
}
final Throwable tx = getInnerCause((Throwable) o, cls);
if (tx != null)
return tx;
}
}
// Check the class hierarchy.
while(x != null){
if( x == cls)
return t;
x = x.getSuperclass();
}
}
// Check the nested cause.
t = t.getCause();
if (t == null)
return null;
return getInnerCause(t, cls);
}
/**
* Examines a stack trace for an instance of the specified cause nested to
* any level within that stack trace.
*
* @param t
* The stack trace.
* @param cls
* The class of exception that you are looking for in the stack
* trace.
*
* @return <code>true</code> iff an exception that is an instance of that
* class iff one exists in the stack trace.
*
* @throws IllegalArgumentException
* if any parameter is null.
*/
// static public boolean isInnerCause(Throwable t, Class cls) {
// Note: Use of generics commented out for 1.4 compatibility.
static public boolean isInnerCause(final Throwable t,
final Class<? extends Throwable> cls) {
return getInnerCause(t, cls) != null;
}
}