001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache license, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the license for the specific language governing permissions and
015 * limitations under the license.
016 */
017package org.apache.logging.log4j.core.pattern;
018
019import org.apache.logging.log4j.core.LogEvent;
020import org.apache.logging.log4j.core.config.plugins.Plugin;
021import org.apache.logging.log4j.core.impl.Log4jLogEvent;
022import org.apache.logging.log4j.core.impl.ThrowableProxy;
023import org.apache.logging.log4j.core.util.Constants;
024
025/**
026 * Outputs the Throwable portion of the LoggingEvent as a full stack trace
027 * unless this converter's option is 'short', where it just outputs the first line of the trace, or if
028 * the number of lines to print is explicitly specified.
029 * <p>
030 * The extended stack trace will also include the location of where the class was loaded from and the
031 * version of the jar if available.
032 */
033@Plugin(name = "RootThrowablePatternConverter", category = PatternConverter.CATEGORY)
034@ConverterKeys({ "rEx", "rThrowable", "rException" })
035public final class RootThrowablePatternConverter extends ThrowablePatternConverter {
036
037    /**
038     * Private constructor.
039     *
040     * @param options options, may be null.
041     */
042    private RootThrowablePatternConverter(final String[] options) {
043        super("RootThrowable", "throwable", options);
044    }
045
046    /**
047     * Gets an instance of the class.
048     *
049     * @param options pattern options, may be null.  If first element is "short",
050     *                only the first line of the throwable will be formatted.
051     * @return instance of class.
052     */
053    public static RootThrowablePatternConverter newInstance(final String[] options) {
054        return new RootThrowablePatternConverter(options);
055    }
056
057    /**
058     * {@inheritDoc}
059     */
060    @Override
061    public void format(final LogEvent event, final StringBuilder toAppendTo) {
062        ThrowableProxy proxy = null;
063        if (event instanceof Log4jLogEvent) {
064            proxy = ((Log4jLogEvent) event).getThrownProxy();
065        }
066        final Throwable throwable = event.getThrown();
067        if (throwable != null && options.anyLines()) {
068            if (proxy == null) {
069                super.format(event, toAppendTo);
070                return;
071            }
072            final String trace = proxy.getCauseStackTraceAsString(options.getPackages());
073            final int len = toAppendTo.length();
074            if (len > 0 && !Character.isWhitespace(toAppendTo.charAt(len - 1))) {
075                toAppendTo.append(' ');
076            }
077            if (!options.allLines() || !Constants.LINE_SEPARATOR.equals(options.getSeparator())) {
078                final StringBuilder sb = new StringBuilder();
079                final String[] array = trace.split(Constants.LINE_SEPARATOR);
080                final int limit = options.minLines(array.length) - 1;
081                for (int i = 0; i <= limit; ++i) {
082                    sb.append(array[i]);
083                    if (i < limit) {
084                        sb.append(options.getSeparator());
085                    }
086                }
087                toAppendTo.append(sb.toString());
088
089            } else {
090                toAppendTo.append(trace);
091            }
092        }
093    }
094}