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.ThrowableProxy;
022import org.apache.logging.log4j.core.util.Constants;
023
024/**
025 * Outputs the Throwable portion of the LoggingEvent as a full stack trace
026 * unless this converter's option is 'short', where it just outputs the first line of the trace, or if
027 * the number of lines to print is explicitly specified.
028 * <p>
029 * The extended stack trace will also include the location of where the class was loaded from and the
030 * version of the jar if available.
031 */
032@Plugin(name = "RootThrowablePatternConverter", category = PatternConverter.CATEGORY)
033@ConverterKeys({ "rEx", "rThrowable", "rException" })
034public final class RootThrowablePatternConverter extends ThrowablePatternConverter {
035
036    /**
037     * Private constructor.
038     *
039     * @param options options, may be null.
040     */
041    private RootThrowablePatternConverter(final String[] options) {
042        super("RootThrowable", "throwable", options);
043    }
044
045    /**
046     * Gets an instance of the class.
047     *
048     * @param options pattern options, may be null.  If first element is "short",
049     *                only the first line of the throwable will be formatted.
050     * @return instance of class.
051     */
052    public static RootThrowablePatternConverter newInstance(final String[] options) {
053        return new RootThrowablePatternConverter(options);
054    }
055
056    /**
057     * {@inheritDoc}
058     */
059    @Override
060    public void format(final LogEvent event, final StringBuilder toAppendTo) {
061        ThrowableProxy proxy = event.getThrownProxy();
062        final Throwable throwable = event.getThrown();
063        if (throwable != null && options.anyLines()) {
064            if (proxy == null) {
065                super.format(event, toAppendTo);
066                return;
067            }
068            final String trace = proxy.getCauseStackTraceAsString(options.getPackages());
069            final int len = toAppendTo.length();
070            if (len > 0 && !Character.isWhitespace(toAppendTo.charAt(len - 1))) {
071                toAppendTo.append(' ');
072            }
073            if (!options.allLines() || !Constants.LINE_SEPARATOR.equals(options.getSeparator())) {
074                final StringBuilder sb = new StringBuilder();
075                final String[] array = trace.split(Constants.LINE_SEPARATOR);
076                final int limit = options.minLines(array.length) - 1;
077                for (int i = 0; i <= limit; ++i) {
078                    sb.append(array[i]);
079                    if (i < limit) {
080                        sb.append(options.getSeparator());
081                    }
082                }
083                toAppendTo.append(sb.toString());
084
085            } else {
086                toAppendTo.append(trace);
087            }
088        }
089    }
090}