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 java.io.PrintWriter;
020import java.io.StringWriter;
021import java.util.ArrayList;
022import java.util.Collections;
023import java.util.List;
024
025import org.apache.logging.log4j.core.LogEvent;
026import org.apache.logging.log4j.core.config.Configuration;
027import org.apache.logging.log4j.core.config.plugins.Plugin;
028import org.apache.logging.log4j.core.impl.ThrowableFormatOptions;
029import org.apache.logging.log4j.core.layout.PatternLayout;
030import org.apache.logging.log4j.core.util.StringBuilderWriter;
031import org.apache.logging.log4j.util.Strings;
032
033
034/**
035 * Outputs the Throwable portion of the LoggingEvent as a full stack trace
036 * unless this converter's option is 'short', where it just outputs the first line of the trace, or if
037 * the number of lines to print is explicitly specified.
038 */
039@Plugin(name = "ThrowablePatternConverter", category = PatternConverter.CATEGORY)
040@ConverterKeys({ "ex", "throwable", "exception" })
041public class ThrowablePatternConverter extends LogEventPatternConverter {
042
043    /**
044     * Lists {@link PatternFormatter}s for the suffix attribute.
045     */
046    protected final List<PatternFormatter> formatters;
047    private String rawOption;
048    private final boolean subShortOption;
049    private final boolean nonStandardLineSeparator;
050
051    /**
052     * Options.
053     */
054    protected final ThrowableFormatOptions options;
055
056    /**
057     * Constructor.
058     * @param name Name of converter.
059     * @param style CSS style for output.
060     * @param options options, may be null.
061     * @deprecated Use ThrowablePatternConverter(String name, String stule, String[] options, Configuration config)
062     */
063    @Deprecated
064    protected ThrowablePatternConverter(final String name, final String style, final String[] options) {
065        this(name, style, options, null);
066    }
067
068    /**
069     * Constructor.
070     * @param name Name of converter.
071     * @param style CSS style for output.
072     * @param options options, may be null.
073     * @param config
074     */
075    protected ThrowablePatternConverter(final String name, final String style, final String[] options, final Configuration config) {
076        super(name, style);
077        this.options = ThrowableFormatOptions.newInstance(options);
078        if (options != null && options.length > 0) {
079            rawOption = options[0];
080        }
081        if (this.options.getSuffix() != null) {
082            final PatternParser parser = PatternLayout.createPatternParser(config);
083            final List<PatternFormatter> parsedSuffixFormatters = parser.parse(this.options.getSuffix());
084            // filter out nested formatters that will handle throwable
085            boolean hasThrowableSuffixFormatter = false;
086            for (final PatternFormatter suffixFormatter : parsedSuffixFormatters) {
087                if (suffixFormatter.handlesThrowable()) {
088                    hasThrowableSuffixFormatter = true;
089                }
090            }
091            if (!hasThrowableSuffixFormatter) {
092                this.formatters = parsedSuffixFormatters;
093            } else {
094                final List<PatternFormatter> suffixFormatters = new ArrayList<>();
095                for (final PatternFormatter suffixFormatter : parsedSuffixFormatters) {
096                    if (!suffixFormatter.handlesThrowable()) {
097                        suffixFormatters.add(suffixFormatter);
098                    }
099                }
100                this.formatters = suffixFormatters;
101            }
102        } else {
103            this.formatters = Collections.emptyList();
104        }
105        subShortOption = ThrowableFormatOptions.MESSAGE.equalsIgnoreCase(rawOption) ||
106                ThrowableFormatOptions.LOCALIZED_MESSAGE.equalsIgnoreCase(rawOption) ||
107                ThrowableFormatOptions.FILE_NAME.equalsIgnoreCase(rawOption) ||
108                ThrowableFormatOptions.LINE_NUMBER.equalsIgnoreCase(rawOption) ||
109                ThrowableFormatOptions.METHOD_NAME.equalsIgnoreCase(rawOption) ||
110                ThrowableFormatOptions.CLASS_NAME.equalsIgnoreCase(rawOption);
111        nonStandardLineSeparator = !Strings.LINE_SEPARATOR.equals(this.options.getSeparator());
112    }
113
114    /**
115     * Gets an instance of the class.
116     *
117     * @param config
118     * @param options pattern options, may be null.  If first element is "short",
119     *                only the first line of the throwable will be formatted.
120     * @return instance of class.
121     */
122    public static ThrowablePatternConverter newInstance(final Configuration config, final String[] options) {
123        return new ThrowablePatternConverter("Throwable", "throwable", options, config);
124    }
125
126    /**
127     * {@inheritDoc}
128     */
129    @Override
130    public void format(final LogEvent event, final StringBuilder buffer) {
131        final Throwable t = event.getThrown();
132
133        if (subShortOption) {
134            formatSubShortOption(t, getSuffix(event), buffer);
135        }
136        else if (t != null && options.anyLines()) {
137            formatOption(t, getSuffix(event), buffer);
138        }
139    }
140
141    private void formatSubShortOption(final Throwable t, final String suffix, final StringBuilder buffer) {
142        StackTraceElement[] trace;
143        StackTraceElement throwingMethod = null;
144        int len;
145
146        if (t != null) {
147            trace = t.getStackTrace();
148            if (trace !=null && trace.length > 0) {
149                throwingMethod = trace[0];
150            }
151        }
152
153        if (t != null && throwingMethod != null) {
154            String toAppend = Strings.EMPTY;
155
156            if (ThrowableFormatOptions.CLASS_NAME.equalsIgnoreCase(rawOption)) {
157                toAppend = throwingMethod.getClassName();
158            }
159            else if (ThrowableFormatOptions.METHOD_NAME.equalsIgnoreCase(rawOption)) {
160                toAppend = throwingMethod.getMethodName();
161            }
162            else if (ThrowableFormatOptions.LINE_NUMBER.equalsIgnoreCase(rawOption)) {
163                toAppend = String.valueOf(throwingMethod.getLineNumber());
164            }
165            else if (ThrowableFormatOptions.MESSAGE.equalsIgnoreCase(rawOption)) {
166                toAppend = t.getMessage();
167            }
168            else if (ThrowableFormatOptions.LOCALIZED_MESSAGE.equalsIgnoreCase(rawOption)) {
169                toAppend = t.getLocalizedMessage();
170            }
171            else if (ThrowableFormatOptions.FILE_NAME.equalsIgnoreCase(rawOption)) {
172                toAppend = throwingMethod.getFileName();
173            }
174
175            len = buffer.length();
176            if (len > 0 && !Character.isWhitespace(buffer.charAt(len - 1))) {
177                buffer.append(' ');
178            }
179            buffer.append(toAppend);
180
181            if (Strings.isNotBlank(suffix)) {
182                buffer.append(' ');
183                buffer.append(suffix);
184            }
185        }
186    }
187
188    private void formatOption(final Throwable throwable, final String suffix, final StringBuilder buffer) {
189        final int len = buffer.length();
190        if (len > 0 && !Character.isWhitespace(buffer.charAt(len - 1))) {
191            buffer.append(' ');
192        }
193        if (!options.allLines() || nonStandardLineSeparator || Strings.isNotBlank(suffix)) {
194            final StringWriter w = new StringWriter();
195            throwable.printStackTrace(new PrintWriter(w));
196
197            final String[] array = w.toString().split(Strings.LINE_SEPARATOR);
198            final int limit = options.minLines(array.length) - 1;
199            final boolean suffixNotBlank = Strings.isNotBlank(suffix);
200            for (int i = 0; i <= limit; ++i) {
201                buffer.append(array[i]);
202                if (suffixNotBlank) {
203                    buffer.append(' ');
204                    buffer.append(suffix);
205                }
206                if (i < limit) {
207                    buffer.append(options.getSeparator());
208                }
209            }
210        } else {
211            throwable.printStackTrace(new PrintWriter(new StringBuilderWriter(buffer)));
212        }
213    }
214
215    /**
216     * This converter obviously handles throwables.
217     *
218     * @return true.
219     */
220    @Override
221    public boolean handlesThrowable() {
222        return true;
223    }
224
225    protected String getSuffix(final LogEvent event) {
226        if (formatters.isEmpty()) {
227            return Strings.EMPTY;
228        }
229        //noinspection ForLoopReplaceableByForEach
230        final StringBuilder toAppendTo = new StringBuilder();
231        for (int i = 0, size = formatters.size(); i <  size; i++) {
232            formatters.get(i).format(event, toAppendTo);
233        }
234        return toAppendTo.toString();
235    }
236
237    public ThrowableFormatOptions getOptions() {
238        return options;
239    }
240}