Exception Helper
/*
* Copyright 2008-2010 the original author or authors
*
* Licensed 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.kaleidofoundry.core.util;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.lang.reflect.Method;
/**
* Exception Helper
*
* @author Jerome RADUGET
*/
public abstract class ThrowableHelper {
// Get javax.servlet.ServletException dynamically if no web container in
// classpath (no need to have servlet.jar in classpath)
final static Class<?> ServletExceptionClass;
static {
Class<?> servletExceptionClass = null;
try {
servletExceptionClass = Class
.forName("javax.servlet.ServletException");
} catch (final Throwable th) {
}
ServletExceptionClass = servletExceptionClass;
}
/**
* @param th
* @return the string representation of an exception stack trace
*/
public static String getStackTrace(final Throwable th) {
final StringWriter writer = new StringWriter();
final PrintWriter pw = new PrintWriter(writer);
fillStackTrace(th, pw);
return writer.toString();
}
/*
* @param ex
*
* @param pw
*/
private static void fillStackTrace(final Throwable ex, final PrintWriter pw) {
if (ex == null) {
pw.print("");
return;
}
// exception stack trace
ex.printStackTrace(pw);
// servlet exception root cause
if (ServletExceptionClass != null
&& ex.getClass().isAssignableFrom(ServletExceptionClass)) {
try {
final Method getRootCauseMethod = ex.getClass().getMethod(
"getRootCause");
final Throwable cause = (Throwable) getRootCauseMethod.invoke(
ex, new Object[] {});
if (null != cause) {
pw.println("Root Cause:");
fillStackTrace(cause, pw);
return;
}
} catch (final Throwable th) {
}
}
// otherwise
final Throwable cause = ex.getCause();
if (null != cause) {
pw.println("Cause:");
fillStackTrace(cause, pw);
}
}
}
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