+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.log4j;
+
+import org.apache.log4j.helpers.OptionConverter;
+import org.apache.log4j.helpers.PatternConverter;
+import org.apache.log4j.pattern.BridgePatternConverter;
+import org.apache.log4j.spi.LoggingEvent;
+
+
+// Contributors: Nelson Minar <nelson@monkey.org>
+// Anders Kristensen <akristensen@dynamicsoft.com>
+
+/**
+ * This class is an enhanced version of org.apache.log4j.PatternLayout
+ * which was originally developed as part of the abandoned log4j 1.3
+ * effort and has been available in the extras companion.
+ * This pattern layout should be used in preference to
+ * org.apache.log4j.PatternLayout except when compatibility
+ * where PatternLayout has been extended either through subclassing
+ * or alternative pattern parsers.
+ *
+ *
+ * <p>A flexible layout configurable with pattern string. The goal of this class
+ * is to {@link #format format} a {@link LoggingEvent} and return the results
+ * in a {@link StringBuffer}. The format of the result depends on the
+ * <em>conversion pattern</em>.
+ * <p>
+ *
+ * <p>The conversion pattern is closely related to the conversion
+ * pattern of the printf function in C. A conversion pattern is
+ * composed of literal text and format control expressions called
+ * <em>conversion specifiers</em>.
+ *
+ * <p><i>Note that you are free to insert any literal text within the
+ * conversion pattern.</i>
+ * </p>
+
+ <p>Each conversion specifier starts with a percent sign (%) and is
+ followed by optional <em>format modifiers</em> and a <em>conversion
+ character</em>. The conversion character specifies the type of
+ data, e.g. category, priority, date, thread name. The format
+ modifiers control such things as field width, padding, left and
+ right justification. The following is a simple example.
+
+ <p>Let the conversion pattern be <b>"%-5p [%t]: %m%n"</b> and assume
+ that the log4j environment was set to use a EnhancedPatternLayout. Then the
+ statements
+ <pre>
+ Category root = Category.getRoot();
+ root.debug("Message 1");
+ root.warn("Message 2");
+ </pre>
+ would yield the output
+ <pre>
+ DEBUG [main]: Message 1
+ WARN [main]: Message 2
+ </pre>
+
+ <p>Note that there is no explicit separator between text and
+ conversion specifiers. The pattern parser knows when it has reached
+ the end of a conversion specifier when it reads a conversion
+ character. In the example above the conversion specifier
+ <b>%-5p</b> means the priority of the logging event should be left
+ justified to a width of five characters.
+
+ The recognized conversion characters are
+
+ <p>
+ <table border="1" CELLPADDING="8">
+ <th>Conversion Character</th>
+ <th>Effect</th>
+
+ <tr>
+ <td align=center><b>c</b></td>
+
+ <td>Used to output the category of the logging event. The
+ category conversion specifier can be optionally followed by
+ NameAbbreviator pattern.
+
+ <p>For example, for the category name "alpha.beta.gamma" the pattern
+ <b>%c{2}</b> will output the last two elements ("beta.gamma"),
+ <b>%c{-2}</b> will remove two elements leaving "gamma",
+ <b>%c{1.}</b> will output "a.b.gamma".
+
+ </td>
+ </tr>
+
+ <tr>
+ <td align=center><b>C</b></td>
+
+ <td>Used to output the fully qualified class name of the caller
+ issuing the logging request. This conversion specifier
+ can be optionally followed by <em>precision specifier</em>, that
+ is a decimal constant in brackets.
+
+ <td>Used to output the category of the logging event. The
+ category conversion specifier can be optionally followed by
+ NameAbbreviator pattern.
+
+ <p>For example, for the category name "alpha.beta.gamma" the pattern
+ <b>%c{2}</b> will output the last two elements ("beta.gamma"),
+ <b>%c{-2}</b> will remove two elements leaving "gamma",
+ <b>%c{1.}</b> will output "a.b.gamma".
+
+ <p><b>WARNING</b> Generating the caller class information is
+ slow. Thus, its use should be avoided unless execution speed is
+ not an issue.
+
+ </td>
+ </tr>
+
+ <tr> <td align=center><b>d</b></td> <td>Used to output the date of
+ the logging event. The date conversion specifier may be
+ followed by a set of braces containing a
+ date and time pattern strings {@link java.text.SimpleDateFormat},
+ <em>ABSOLUTE</em>, <em>DATE</em> or <em>ISO8601</em>
+ and a set of braces containing a time zone id per
+ {@link java.util.TimeZone#getTimeZone(String)}.
+ For example, <b>%d{HH:mm:ss,SSS}</b>,
+ <b>%d{dd MMM yyyy HH:mm:ss,SSS}</b>,
+ <b>%d{DATE}</b> or <b>%d{HH:mm:ss}{GMT+0}</b>. If no date format specifier is given then
+ ISO8601 format is assumed.
+ </td>
+ </tr>
+
+ <tr>
+ <td align=center><b>F</b></td>
+
+ <td>Used to output the file name where the logging request was
+ issued.
+
+ <p><b>WARNING</b> Generating caller location information is
+ extremely slow and should be avoided unless execution speed
+ is not an issue.
+
+ </tr>
+
+ <tr>
+ <td align=center><b>l</b></td>
+
+ <td>Used to output location information of the caller which generated
+ the logging event.
+
+ <p>The location information depends on the JVM implementation but
+ usually consists of the fully qualified name of the calling
+ method followed by the callers source the file name and line
+ number between parentheses.
+
+ <p>The location information can be very useful. However, its
+ generation is <em>extremely</em> slow and should be avoided
+ unless execution speed is not an issue.
+
+ </td>
+ </tr>
+
+ <tr>
+ <td align=center><b>L</b></td>
+
+ <td>Used to output the line number from where the logging request
+ was issued.
+
+ <p><b>WARNING</b> Generating caller location information is
+ extremely slow and should be avoided unless execution speed
+ is not an issue.
+
+ </tr>
+
+
+ <tr>
+ <td align=center><b>m</b></td>
+ <td>Used to output the application supplied message associated with
+ the logging event.</td>
+ </tr>
+
+ <tr>
+ <td align=center><b>M</b></td>
+
+ <td>Used to output the method name where the logging request was
+ issued.
+
+ <p><b>WARNING</b> Generating caller location information is
+ extremely slow and should be avoided unless execution speed
+ is not an issue.
+
+ </tr>
+
+ <tr>
+ <td align=center><b>n</b></td>
+
+ <td>Outputs the platform dependent line separator character or
+ characters.
+
+ <p>This conversion character offers practically the same
+ performance as using non-portable line separator strings such as
+ "\n", or "\r\n". Thus, it is the preferred way of specifying a
+ line separator.
+
+
+ </tr>
+
+ <tr>
+ <td align=center><b>p</b></td>
+ <td>Used to output the priority of the logging event.</td>
+ </tr>
+
+ <tr>
+
+ <td align=center><b>r</b></td>
+
+ <td>Used to output the number of milliseconds elapsed since the construction
+ of the layout until the creation of the logging event.</td>
+ </tr>
+
+
+ <tr>
+ <td align=center><b>t</b></td>
+
+ <td>Used to output the name of the thread that generated the
+ logging event.</td>
+
+ </tr>
+
+ <tr>
+
+ <td align=center><b>x</b></td>
+
+ <td>Used to output the NDC (nested diagnostic context) associated
+ with the thread that generated the logging event.
+ </td>
+ </tr>
+
+
+ <tr>
+ <td align=center><b>X</b></td>
+
+ <td>
+
+ <p>Used to output the MDC (mapped diagnostic context) associated
+ with the thread that generated the logging event. The <b>X</b>
+ conversion character can be followed by the key for the
+ map placed between braces, as in <b>%X{clientNumber}</b> where
+ <code>clientNumber</code> is the key. The value in the MDC
+ corresponding to the key will be output. If no additional sub-option
+ is specified, then the entire contents of the MDC key value pair set
+ is output using a format {{key1,val1},{key2,val2}}</p>
+
+ <p>See {@link MDC} class for more details.
+ </p>
+
+ </td>
+ </tr>
+
+ <tr>
+ <td align=center><b>properties</b></td>
+
+ <td>
+ <p>Used to output the Properties associated
+ with the logging event. The <b>properties</b>
+ conversion word can be followed by the key for the
+ map placed between braces, as in <b>%properties{application}</b> where
+ <code>application</code> is the key. The value in the Properties bundle
+ corresponding to the key will be output. If no additional sub-option
+ is specified, then the entire contents of the Properties key value pair set
+ is output using a format {{key1,val1},{key2,val2}}</p>
+ </td>
+ </tr>
+
+ <tr>
+ <td align=center><b>throwable</b></td>
+
+ <td>
+ <p>Used to output the Throwable trace that has been bound to the LoggingEvent, by
+ default this will output the full trace as one would normally
+ find by a call to Throwable.printStackTrace().
+ <b>%throwable{short}</b> or <b>%throwable{1}</b> will output the first line of
+ stack trace. <b>throwable{none}</b> or <b>throwable{0}</b> will suppress
+ the stack trace. <b>%throwable{n}</b> will output n lines of stack trace
+ if a positive integer or omit the last -n lines if a negative integer.
+ If no %throwable pattern is specified, the appender will take
+ responsibility to output the stack trace as it sees fit.</p>
+ </td>
+ </tr>
+
+ <tr>
+
+ <td align=center><b>%</b></td>
+
+ <td>The sequence %% outputs a single percent sign.
+ </td>
+ </tr>
+
+ </table>
+
+ <p>By default the relevant information is output as is. However,
+ with the aid of format modifiers it is possible to change the
+ minimum field width, the maximum field width, justification
+ and truncation.
+
+ <p>The optional format modifier are placed between the percent sign
+ and the conversion character.
+
+ <p>The <em>left justification flag</em>, the minus sign (-),
+ the <em>right truncation flag</em>, the exclamation mark (!),
+ or any combination appear first. Followed by the
+ optional <em>minimum field width</em> modifier. This is a decimal
+ constant that represents the minimum number of characters to
+ output. If the data item requires fewer characters, it is padded on
+ either the left or the right until the minimum width is
+ reached. The default is to pad on the left (right justify) but you
+ can specify right padding with the left justification flag. The
+ padding character is space. If the data item is larger than the
+ minimum field width, the field is expanded to accommodate the
+ data. The value is never truncated.
+
+ <p>This behavior can be changed using the <em>maximum field
+ width</em> modifier which is designated by a period followed by a
+ decimal constant. If the data item is longer than the maximum
+ field, then the extra characters are removed from the
+ <em>beginning</em> of the data item and not from the end. For
+ example, it the maximum field width is eight and the data item is
+ ten characters long, then the first two characters of the data item
+ are dropped. This behavior deviates from the printf function in C
+ where truncation is done from the end. The <em>right truncation flag</em>,
+ described previously, will override this behavior.
+
+ <p>Below are various format modifier examples for the category
+ conversion specifier.
+
+ <p>
+ <TABLE BORDER=1 CELLPADDING=8>
+ <th>Format modifier
+ <th>left justify
+ <th>minimum width
+ <th>maximum width
+ <th>comment
+
+ <tr>
+ <td align=center>%20c</td>
+ <td align=center>false</td>
+ <td align=center>20</td>
+ <td align=center>none</td>
+
+ <td>Left pad with spaces if the category name is less than 20
+ characters long.
+
+ <tr> <td align=center>%-20c</td> <td align=center>true</td> <td
+ align=center>20</td> <td align=center>none</td> <td>Right pad with
+ spaces if the category name is less than 20 characters long.
+
+ <tr>
+ <td align=center>%.30c</td>
+ <td align=center>NA</td>
+ <td align=center>none</td>
+ <td align=center>30</td>
+
+ <td>Truncate from the beginning if the category name is longer than 30
+ characters.
+
+ <tr>
+ <td align=center>%!.30c</td>
+ <td align=center>NA</td>
+ <td align=center>none</td>
+ <td align=center>30</td>
+
+ <td>Truncate from the end if the category name is longer than 30
+ characters.
+
+ <tr>
+ <td align=center>%20.30c</td>
+ <td align=center>false</td>
+ <td align=center>20</td>
+ <td align=center>30</td>
+
+ <td>Left pad with spaces if the category name is shorter than 20
+ characters. However, if category name is longer than 30 characters,
+ then truncate from the beginning.
+
+ <tr>
+ <td align=center>%-20.30c</td>
+ <td align=center>true</td>
+ <td align=center>20</td>
+ <td align=center>30</td>
+
+ <td>Right pad with spaces if the category name is shorter than 20
+ characters. However, if category name is longer than 30 characters,
+ then truncate from the beginning.
+
+ </table>
+
+ <p>Below are some examples of conversion patterns.
+
+ <dl>
+
+ <p><dt><b>%r [%t] %-5p %c %x - %m%n</b>
+ <p><dd>This is essentially the TTCC layout.
+
+ <p><dt><b>%-6r [%15.15t] %-5p %30.30c %x - %m%n</b>
+
+ <p><dd>Similar to the TTCC layout except that the relative time is
+ right padded if less than 6 digits, thread name is right padded if
+ less than 15 characters and truncated if longer and the category
+ name is left padded if shorter than 30 characters and truncated if
+ longer.
+
+ </dl>
+
+ <p>The above text is largely inspired from Peter A. Darnell and
+ Philip E. Margolis' highly recommended book "C -- a Software
+ Engineering Approach", ISBN 0-387-97389-3.
+
+ @author <a href="mailto:cakalijp@Maritz.com">James P. Cakalic</a>
+ @author Ceki Gülcü
+
+
+ @since 1.2.16 */
+public class EnhancedPatternLayout extends Layout {
+ /** Default pattern string for log output. Currently set to the
+ string <b>"%m%n"</b> which just prints the application supplied
+ message. */
+ public static final String DEFAULT_CONVERSION_PATTERN = "%m%n";
+
+ /** A conversion pattern equivalent to the TTCCCLayout.
+ Current value is <b>%r [%t] %p %c %x - %m%n</b>. */
+ public static final String TTCC_CONVERSION_PATTERN =
+ "%r [%t] %p %c %x - %m%n";
+
+ /**
+ * Initial size of internal buffer, no longer used.
+ * @deprecated since 1.3
+ */
+ protected final int BUF_SIZE = 256;
+
+ /**
+ * Maximum capacity of internal buffer, no longer used.
+ * @deprecated since 1.3
+ */
+ protected final int MAX_CAPACITY = 1024;
+
+ /**
+ * Customized pattern conversion rules are stored under this key in the
+ * {@link org.apache.log4j.spi.LoggerRepository LoggerRepository} object store.
+ */
+ public static final String PATTERN_RULE_REGISTRY = "PATTERN_RULE_REGISTRY";
+
+
+ /**
+ * Initial converter for pattern.
+ */
+ private PatternConverter head;
+
+ /**
+ * Conversion pattern.
+ */
+ private String conversionPattern;
+
+ /**
+ * True if any element in pattern formats information from exceptions.
+ */
+ private boolean handlesExceptions;
+
+ /**
+ Constructs a EnhancedPatternLayout using the DEFAULT_LAYOUT_PATTERN.
+
+ The default pattern just produces the application supplied message.
+ */
+ public EnhancedPatternLayout() {
+ this(DEFAULT_CONVERSION_PATTERN);
+ }
+
+ /**
+ * Constructs a EnhancedPatternLayout using the supplied conversion pattern.
+ * @param pattern conversion pattern.
+ */
+ public EnhancedPatternLayout(final String pattern) {
+ this.conversionPattern = pattern;
+ head = createPatternParser(
+ (pattern == null) ? DEFAULT_CONVERSION_PATTERN : pattern).parse();
+ if (head instanceof BridgePatternConverter) {
+ handlesExceptions = !((BridgePatternConverter) head).ignoresThrowable();
+ } else {
+ handlesExceptions = false;
+ }
+ }
+
+ /**
+ * Set the <b>ConversionPattern</b> option. This is the string which
+ * controls formatting and consists of a mix of literal content and
+ * conversion specifiers.
+ *
+ * @param conversionPattern conversion pattern.
+ */
+ public void setConversionPattern(final String conversionPattern) {
+ this.conversionPattern =
+ OptionConverter.convertSpecialChars(conversionPattern);
+ head = createPatternParser(this.conversionPattern).parse();
+ if (head instanceof BridgePatternConverter) {
+ handlesExceptions = !((BridgePatternConverter) head).ignoresThrowable();
+ } else {
+ handlesExceptions = false;
+ }
+ }
+
+ /**
+ * Returns the value of the <b>ConversionPattern</b> option.
+ * @return conversion pattern.
+ */
+ public String getConversionPattern() {
+ return conversionPattern;
+ }
+
+
+ /**
+ Returns PatternParser used to parse the conversion string. Subclasses
+ may override this to return a subclass of PatternParser which recognize
+ custom conversion characters.
+
+ @since 0.9.0
+ */
+ protected org.apache.log4j.helpers.PatternParser createPatternParser(String pattern) {
+ return new org.apache.log4j.pattern.BridgePatternParser(pattern);
+ }
+
+
+ /**
+ Activates the conversion pattern. Do not forget to call this method after
+ you change the parameters of the EnhancedPatternLayout instance.
+ */
+ public void activateOptions() {
+ // nothing to do.
+ }
+
+
+ /**
+ * Formats a logging event to a writer.
+ * @param event logging event to be formatted.
+ */
+ public String format(final LoggingEvent event) {
+ StringBuffer buf = new StringBuffer();
+ for(PatternConverter c = head;
+ c != null;
+ c = c.next) {
+ c.format(buf, event);
+ }
+ return buf.toString();
+ }
+
+ /**
+ * Will return false if any of the conversion specifiers in the pattern
+ * handles {@link Exception Exceptions}.
+ * @return true if the pattern formats any information from exceptions.
+ */
+ public boolean ignoresThrowable() {
+ return !handlesExceptions;
+ }
+}