001/**
002 * Logback: the reliable, generic, fast and flexible logging framework.
003 * Copyright (C) 1999-2015, QOS.ch. All rights reserved.
004 *
005 * This program and the accompanying materials are dual-licensed under
006 * either the terms of the Eclipse Public License v1.0 as published by
007 * the Eclipse Foundation
008 *
009 *   or (per the licensee's choosing)
010 *
011 * under the terms of the GNU Lesser General Public License version 2.1
012 * as published by the Free Software Foundation.
013 */
014package ch.qos.logback.classic.pattern;
015
016import ch.qos.logback.classic.PatternLayout;
017import ch.qos.logback.classic.spi.ILoggingEvent;
018import ch.qos.logback.core.CoreConstants;
019
020/**
021 * Always returns an empty string.
022 * <p>
023 * This converter is useful to pretend that the converter chain for
024 * PatternLayout actually handles exceptions, when in fact it does not. By
025 * adding %nopex to the conversion pattern, the user can bypass the automatic
026 * addition of %ex conversion pattern for patterns which do not contain a
027 * converter handling exceptions.
028 * 
029 * <p>
030 * Users can ignore the existence of this converter, unless they want to
031 * suppress the automatic printing of exceptions by {@link PatternLayout}.
032 * 
033 * @author Ceki G&uuml;lc&uuml;
034 */
035public class NopThrowableInformationConverter extends ThrowableHandlingConverter {
036
037    public String convert(ILoggingEvent event) {
038        return CoreConstants.EMPTY_STRING;
039    }
040
041}