mcconnell 2003/03/07 18:37:11
Added: assembly-spi/src/java/org/apache/avalon/assembly/util
ExceptionHelper.java package.html
Log:
Moved exception helper class from assembly into SPI.
Revision Changes Path
1.1
avalon-sandbox/assembly-spi/src/java/org/apache/avalon/assembly/util/ExceptionHelper.java
Index: ExceptionHelper.java
===================================================================
/* ====================================================================
* The Apache Software License, Version 1.1
*
* Copyright (c) 2002 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software
* itself, if and wherever such third-party acknowledgments
* normally appear.
*
* 4. The names "Jakarta", "Avalon", and "Apache Software Foundation"
* must not be used to endorse or promote products derived from this
* software without prior written permission. For written
* permission, please contact [EMAIL PROTECTED]
*
* 5. Products derived from this software may not be called "Apache",
* nor may "Apache" appear in their name, without prior written
* permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*/
package org.apache.avalon.assembly.util;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.lang.reflect.Method;
import java.util.StringTokenizer;
/**
* General utilities supporting the packaging of exception messages.
* @author <a href="mailto:[EMAIL PROTECTED]">Stephen McConnell</a>
*/
public class ExceptionHelper
{
private static final String LINE_SEPARATOR = System.getProperty(
"line.separator" );
/**
* Prints the exception to the standard error out together with
* cause statements.
* @param e the exception to print
*/
public static void printException( Throwable e )
{
printException( null, e );
}
/**
* Prints the exception to the standard error out together with
* cause statements.
* @param label label identifying the error
* @param e the exception to print
*/
public static void printException( String label, Throwable e )
{
printException( label, e, null );
}
/**
* Prints the exception to the standard error out together with
* source and cause statements.
* @param label label identifying the error
* @param e the exception to print
* @param source the source of the request
*/
public static void printException( String label, Throwable e, Object source )
{
printException( label, e, source, false );
}
/**
* Prints the exception to the standard error out together with
* source and cause statements.
* @param label label identifying the error
* @param e the exception to print
* @param source the source of the request
* @param trace boolean value inidication if a stack trace though be included
*/
public static void printException( String label, Throwable e, Object source,
boolean trace )
{
if( e == null )
{
throw new NullPointerException( "throwable" );
}
java.io.PrintStream out = System.err;
synchronized( out )
{
out.println(
"===================================================================" );
if( label != null )
{
out.println( "Message: " + label );
}
if( source != null )
{
out.println( "Source: " + source );
}
out.println( "Exception: " + e.toString() );
if( getCause( e ) != null )
{
printCause( out, e );
}
out.println(
"===================================================================" );
if( trace )
{
Throwable root = getLastThrowable( e );
root.printStackTrace();
out.println(
"===================================================================" );
}
}
}
/**
* Returns the exception and causal exceptions as a formatted string.
* @param message the header message
* @param e the exception
* @return String the formatting string
*/
public static String packException( final String message, final Throwable e )
{
return packException( message, e, true );
}
/**
* Returns the exception and causal exceptions as a formatted string.
* @param message the header message
* @param e the exception
* @return String the formatting string
*/
public static String packException( final String message, final Throwable e,
boolean stack )
{
StringBuffer buffer = new StringBuffer();
buffer.append( "Message: " + message );
buffer.append(
"\n===================================================================" );
if( e == null )
{
return buffer.toString();
}
else
{
buffer.append( "\n\nException: " + e.getClass().getName() );
buffer.append( "\n" + e.getMessage() );
packCause( buffer, getCause( e ) ).toString();
buffer.append(
"\n\n===================================================================" );
}
Throwable root = getLastThrowable( e );
if(( root != null ) && stack )
{
String[] trace = captureStackTrace( root );
for( int i = 0; i < trace.length; i++ )
{
buffer.append( "\n" + trace[ i ] );
}
}
buffer.append(
"\n===================================================================" );
return buffer.toString();
}
private static StringBuffer packCause( StringBuffer buffer, Throwable cause )
{
if( cause == null )
{
return buffer;
}
buffer.append( "\n\nCause: " + cause.getClass().getName() );
buffer.append( "\n" + cause.getMessage() );
return packCause( buffer, getCause( cause ) );
}
private static Throwable getLastThrowable( Throwable exception )
{
Throwable cause = getCause( exception );
if( cause != null )
{
return getLastThrowable( cause );
}
return exception;
}
private static Throwable getCause( Throwable exception )
{
if( exception == null )
{
throw new NullPointerException( "exception" );
}
try
{
Method method = exception.getClass().getMethod( "getCause", new Class[ 0
] );
return (Throwable)method.invoke( exception, new Object[ 0 ] );
}
catch( Throwable e )
{
return null;
}
}
/**
* Captures the stack trace associated with this exception.
*
* @param throwable a <code>Throwable</code>
* @return an array of Strings describing stack frames.
*/
private static String[] captureStackTrace( final Throwable throwable )
{
final StringWriter sw = new StringWriter();
throwable.printStackTrace( new PrintWriter( sw, true ) );
return splitString( sw.toString(), LINE_SEPARATOR );
}
/**
* Splits the string on every token into an array of stack frames.
*
* @param string the string to split
* @param onToken the token to split on
* @return the resultant array
*/
private static String[] splitString( final String string, final String onToken )
{
final StringTokenizer tokenizer = new StringTokenizer( string, onToken );
final String[] result = new String[ tokenizer.countTokens() ];
for( int i = 0; i < result.length; i++ )
{
result[ i ] = tokenizer.nextToken();
}
return result;
}
private static void printCause( java.io.PrintStream out, Throwable e )
{
Throwable cause = getCause( e );
out.println( "Cause: " + cause.toString() );
if( getCause( cause ) != null )
{
printCause( out, cause );
}
}
}
1.1
avalon-sandbox/assembly-spi/src/java/org/apache/avalon/assembly/util/package.html
Index: package.html
===================================================================
<body>
<p>
The <code>util</code> package contains a number of general component utilities.</p>
</body>
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