org.apache.myfaces.shared_tomahawk.util.ExceptionUtils Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.myfaces.shared_tomahawk.util;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;
/**
* Various helpers to deal with exception
*
* @author [email protected]
*/
public final class ExceptionUtils
{
private ExceptionUtils()
{
}
/**
*
* returns a list of all throwables (including the one you passed in) wrapped by the given throwable.
* In contrast to a simple call to getClause() on each throwable it will also check if
* the throwable class contain a method getRootCause() (e.g. ServletException or JspException)
* and call it instead.
*
*
* The first list element will your passed in exception, the last list element is the cause.
*
*/
public static List getExceptions(Throwable cause)
{
List exceptions = new ArrayList(10);
exceptions.add(cause);
do
{
Throwable nextCause;
try
{
Method rootCause = cause.getClass().getMethod("getRootCause", new Class[]{});
nextCause = (Throwable) rootCause.invoke(cause, new Object[]{});
}
catch(Exception e)
{
nextCause = cause.getCause();
}
if (cause == nextCause)
{
break;
}
if (nextCause != null)
{
exceptions.add(nextCause);
}
cause = nextCause;
}
while (cause != null);
return exceptions;
}
/**
* Find a throwable message starting with the last element.
* Returns the first throwable message where throwable.getMessage() != null
*/
public static String getExceptionMessage(List throwables)
{
if (throwables == null)
{
return null;
}
for (int i = throwables.size()-1; i>0; i--)
{
Throwable t = (Throwable) throwables.get(i);
if (t.getMessage() != null)
{
return t.getMessage();
}
}
return null;
}
}