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     */
017    package org.apache.logging.log4j.core.pattern;
018    
019    import org.apache.logging.log4j.core.LogEvent;
020    import org.apache.logging.log4j.core.config.plugins.Plugin;
021    import org.apache.logging.log4j.core.helpers.Constants;
022    import org.apache.logging.log4j.core.impl.ThrowableProxy;
023    
024    /**
025     * Outputs the Throwable portion of the LoggingEvent as a full stacktrace
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", type = "Converter")
033    @ConverterKeys({"rEx", "rThrowable", "rException" })
034    public 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            final Throwable throwable = event.getThrown();
062            if (throwable != null && options.anyLines()) {
063                if (!(throwable instanceof ThrowableProxy)) {
064                    super.format(event, toAppendTo);
065                    return;
066                }
067                final ThrowableProxy t = (ThrowableProxy) throwable;
068                final String trace = t.getRootCauseStackTrace(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_SEP.equals(options.getSeparator())) {
074                    final StringBuilder sb = new StringBuilder();
075                    final String[] array = trace.split(Constants.LINE_SEP);
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    }