/*
* Copyright 2001-2004 The Apache Software Foundation
*
* 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.apache.commons.collections;
import java.io.PrintStream;
import java.io.PrintWriter;
/**
* Runtime exception thrown from functors.
* If required, a root cause error can be wrapped within this one.
*
* @since Commons Collections 3.0
* @version $Revision: 155406 $ $Date: 2005-02-26 12:55:26 +0000 (Sat, 26 Feb 2005) $
*
* @author Stephen Colebourne
*/
public class FunctorException extends RuntimeException {
/**
* Does JDK support nested exceptions
*/
private static final boolean JDK_SUPPORTS_NESTED;
static {
boolean flag = false;
try {
Throwable.class.getDeclaredMethod("getCause", new Class[0]);
flag = true;
} catch (NoSuchMethodException ex) {
flag = false;
}
JDK_SUPPORTS_NESTED = flag;
}
/**
* Root cause of the exception
*/
private final Throwable rootCause;
/**
* Constructs a new <code>FunctorException</code> without specified
* detail message.
*/
public FunctorException() {
super();
this.rootCause = null;
}
/**
* Constructs a new <code>FunctorException</code> with specified
* detail message.
*
* @param msg the error message.
*/
public FunctorException(String msg) {
super(msg);
this.rootCause = null;
}
/**
* Constructs a new <code>FunctorException</code> with specified
* nested <code>Throwable</code> root cause.
*
* @param rootCause the exception or error that caused this exception
* to be thrown.
*/
public FunctorException(Throwable rootCause) {
super((rootCause == null ? null : rootCause.getMessage()));
this.rootCause = rootCause;
}
/**
* Constructs a new <code>FunctorException</code> with specified
* detail message and nested <code>Throwable</code> root cause.
*
* @param msg the error message.
* @param rootCause the exception or error that caused this exception
* to be thrown.
*/
public FunctorException(String msg, Throwable rootCause) {
super(msg);
this.rootCause = rootCause;
}
/**
* Gets the cause of this throwable.
*
* @return the cause of this throwable, or <code>null</code>
*/
public Throwable getCause() {
return rootCause;
}
/**
* Prints the stack trace of this exception to the standard error stream.
*/
public void printStackTrace() {
printStackTrace(System.err);
}
/**
* Prints the stack trace of this exception to the specified stream.
*
* @param out the <code>PrintStream</code> to use for output
*/
public void printStackTrace(PrintStream out) {
synchronized (out) {
PrintWriter pw = new PrintWriter(out, false);
printStackTrace(pw);
// Flush the PrintWriter before it's GC'ed.
pw.flush();
}
}
/**
* Prints the stack trace of this exception to the specified writer.
*
* @param out the <code>PrintWriter</code> to use for output
*/
public void printStackTrace(PrintWriter out) {
synchronized (out) {
super.printStackTrace(out);
if (rootCause != null && JDK_SUPPORTS_NESTED == false) {
out.print("Caused by: ");
rootCause.printStackTrace(out);
}
}
}
}