PatternParser.java
/*
* 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.pattern;
import org.apache.log4j.helpers.Loader;
import org.apache.log4j.helpers.LogLog;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
// Contributors: Nelson Minar <(nelson@monkey.org>
// Igor E. Poteryaev <jah@mail.ru>
// Reinhard Deschler <reinhard.deschler@web.de>
/**
* Most of the work of the {@link org.apache.log4j.EnhancedPatternLayout} class is delegated to the PatternParser
* class.
* <p>
* It is this class that parses conversion patterns and creates a chained list of
* {@link PatternConverter PatternConverters}.
*
* @author James P. Cakalic
* @author Ceki Gülcü
* @author Anders Kristensen
* @author Paul Smith
* @author Curt Arnold
*/
public final class PatternParser {
/**
* Escape character for format specifier.
*/
private static final char ESCAPE_CHAR = '%';
/**
* Literal state.
*/
private static final int LITERAL_STATE = 0;
/**
* In converter name state.
*/
private static final int CONVERTER_STATE = 1;
/**
* Dot state.
*/
private static final int DOT_STATE = 3;
/**
* Min state.
*/
private static final int MIN_STATE = 4;
/**
* Max state.
*/
private static final int MAX_STATE = 5;
/**
* Standard format specifiers for EnhancedPatternLayout.
*/
private static final Map PATTERN_LAYOUT_RULES;
/**
* Standard format specifiers for rolling file appenders.
*/
private static final Map FILENAME_PATTERN_RULES;
static {
// We set the global rules in the static initializer of PatternParser class
Map rules = new HashMap(17);
rules.put("c", LoggerPatternConverter.class);
rules.put("logger", LoggerPatternConverter.class);
rules.put("C", ClassNamePatternConverter.class);
rules.put("class", ClassNamePatternConverter.class);
rules.put("d", DatePatternConverter.class);
rules.put("date", DatePatternConverter.class);
rules.put("F", FileLocationPatternConverter.class);
rules.put("file", FileLocationPatternConverter.class);
rules.put("l", FullLocationPatternConverter.class);
rules.put("L", LineLocationPatternConverter.class);
rules.put("line", LineLocationPatternConverter.class);
rules.put("m", MessagePatternConverter.class);
rules.put("message", MessagePatternConverter.class);
rules.put("n", LineSeparatorPatternConverter.class);
rules.put("M", MethodLocationPatternConverter.class);
rules.put("method", MethodLocationPatternConverter.class);
rules.put("p", LevelPatternConverter.class);
rules.put("level", LevelPatternConverter.class);
rules.put("r", RelativeTimePatternConverter.class);
rules.put("relative", RelativeTimePatternConverter.class);
rules.put("t", ThreadPatternConverter.class);
rules.put("thread", ThreadPatternConverter.class);
rules.put("x", NDCPatternConverter.class);
rules.put("ndc", NDCPatternConverter.class);
rules.put("X", PropertiesPatternConverter.class);
rules.put("properties", PropertiesPatternConverter.class);
rules.put("sn", SequenceNumberPatternConverter.class);
rules.put("sequenceNumber", SequenceNumberPatternConverter.class);
rules.put("throwable", ThrowableInformationPatternConverter.class);
PATTERN_LAYOUT_RULES = new ReadOnlyMap(rules);
Map fnameRules = new HashMap(4);
fnameRules.put("d", FileDatePatternConverter.class);
fnameRules.put("date", FileDatePatternConverter.class);
fnameRules.put("i", IntegerPatternConverter.class);
fnameRules.put("index", IntegerPatternConverter.class);
FILENAME_PATTERN_RULES = new ReadOnlyMap(fnameRules);
}
/**
* Private constructor.
*/
private PatternParser() {
}
/**
* Get standard format specifiers for EnhancedPatternLayout.
*
* @return read-only map of format converter classes keyed by format specifier strings.
*/
public static Map getPatternLayoutRules() {
return PATTERN_LAYOUT_RULES;
}
/**
* Get standard format specifiers for rolling file appender file specification.
*
* @return read-only map of format converter classes keyed by format specifier strings.
*/
public static Map getFileNamePatternRules() {
return FILENAME_PATTERN_RULES;
}
/**
* Extract the converter identifier found at position i.
* <p>
* After this function returns, the variable i will point to the first char after the end of the converter
* identifier.
* <p>
* If i points to a char which is not a character acceptable at the start of a unicode identifier, the value null is
* returned.
*
* @param lastChar last processed character.
* @param pattern format string.
* @param i current index into pattern format.
* @param convBuf buffer to receive conversion specifier.
* @param currentLiteral literal to be output in case format specifier in unrecognized.
* @return position in pattern after converter.
*/
private static int extractConverter(char lastChar, final String pattern, int i, final StringBuilder convBuf,
final StringBuilder currentLiteral) {
convBuf.setLength(0);
// When this method is called, lastChar points to the first character of the
// conversion word. For example:
// For "%hello" lastChar = 'h'
// For "%-5hello" lastChar = 'h'
// System.out.println("lastchar is "+lastChar);
if (!Character.isUnicodeIdentifierStart(lastChar)) {
return i;
}
convBuf.append(lastChar);
while ((i < pattern.length()) && Character.isUnicodeIdentifierPart(pattern.charAt(i))) {
convBuf.append(pattern.charAt(i));
currentLiteral.append(pattern.charAt(i));
// System.out.println("conv buffer is now ["+convBuf+"].");
i++;
}
return i;
}
/**
* Extract options.
*
* @param pattern conversion pattern.
* @param i start of options.
* @param options array to receive extracted options
* @return position in pattern after options.
*/
private static int extractOptions(String pattern, int i, List options) {
while ((i < pattern.length()) && (pattern.charAt(i) == '{')) {
int end = pattern.indexOf('}', i);
if (end == -1) {
break;
}
String r = pattern.substring(i + 1, end);
options.add(r);
i = end + 1;
}
return i;
}
/**
* Parse a format specifier.
*
* @param pattern pattern to parse.
* @param patternConverters list to receive pattern converters.
* @param formattingInfos list to receive field specifiers corresponding to pattern converters.
* @param converterRegistry map of user-supported pattern converters keyed by format specifier, may be null.
* @param rules map of stock pattern converters keyed by format specifier.
*/
public static void parse(final String pattern, final List patternConverters, final List formattingInfos,
final Map converterRegistry, final Map rules) {
if (pattern == null) {
throw new NullPointerException("pattern");
}
StringBuilder currentLiteral = new StringBuilder(32);
int patternLength = pattern.length();
int state = LITERAL_STATE;
char c;
int i = 0;
FormattingInfo formattingInfo = FormattingInfo.getDefault();
while (i < patternLength) {
c = pattern.charAt(i++);
switch (state) {
case LITERAL_STATE:
// In literal state, the last char is always a literal.
if (i == patternLength) {
currentLiteral.append(c);
continue;
}
if (c == ESCAPE_CHAR) {
// peek at the next char.
switch (pattern.charAt(i)) {
case ESCAPE_CHAR:
currentLiteral.append(c);
i++; // move pointer
break;
default:
if (currentLiteral.length() != 0) {
patternConverters.add(new LiteralPatternConverter(currentLiteral.toString()));
formattingInfos.add(FormattingInfo.getDefault());
}
currentLiteral.setLength(0);
currentLiteral.append(c); // append %
state = CONVERTER_STATE;
formattingInfo = FormattingInfo.getDefault();
}
} else {
currentLiteral.append(c);
}
break;
case CONVERTER_STATE:
currentLiteral.append(c);
switch (c) {
case '-':
formattingInfo = new FormattingInfo(true, formattingInfo.getMinLength(),
formattingInfo.getMaxLength());
break;
case '.':
state = DOT_STATE;
break;
default:
if ((c >= '0') && (c <= '9')) {
formattingInfo = new FormattingInfo(formattingInfo.isLeftAligned(), c - '0',
formattingInfo.getMaxLength());
state = MIN_STATE;
} else {
i = finalizeConverter(c, pattern, i, currentLiteral, formattingInfo, converterRegistry, rules,
patternConverters, formattingInfos);
// Next pattern is assumed to be a literal.
state = LITERAL_STATE;
formattingInfo = FormattingInfo.getDefault();
currentLiteral.setLength(0);
}
} // switch
break;
case MIN_STATE:
currentLiteral.append(c);
if ((c >= '0') && (c <= '9')) {
formattingInfo = new FormattingInfo(formattingInfo.isLeftAligned(),
(formattingInfo.getMinLength() * 10) + (c - '0'), formattingInfo.getMaxLength());
} else if (c == '.') {
state = DOT_STATE;
} else {
i = finalizeConverter(c, pattern, i, currentLiteral, formattingInfo, converterRegistry, rules,
patternConverters, formattingInfos);
state = LITERAL_STATE;
formattingInfo = FormattingInfo.getDefault();
currentLiteral.setLength(0);
}
break;
case DOT_STATE:
currentLiteral.append(c);
if ((c >= '0') && (c <= '9')) {
formattingInfo = new FormattingInfo(formattingInfo.isLeftAligned(), formattingInfo.getMinLength(),
c - '0');
state = MAX_STATE;
} else {
LogLog.error("Error occured in position " + i + ".\n Was expecting digit, instead got char \"" + c
+ "\".");
state = LITERAL_STATE;
}
break;
case MAX_STATE:
currentLiteral.append(c);
if ((c >= '0') && (c <= '9')) {
formattingInfo = new FormattingInfo(formattingInfo.isLeftAligned(), formattingInfo.getMinLength(),
(formattingInfo.getMaxLength() * 10) + (c - '0'));
} else {
i = finalizeConverter(c, pattern, i, currentLiteral, formattingInfo, converterRegistry, rules,
patternConverters, formattingInfos);
state = LITERAL_STATE;
formattingInfo = FormattingInfo.getDefault();
currentLiteral.setLength(0);
}
break;
} // switch
}
// while
if (currentLiteral.length() != 0) {
patternConverters.add(new LiteralPatternConverter(currentLiteral.toString()));
formattingInfos.add(FormattingInfo.getDefault());
}
}
/**
* Creates a new PatternConverter.
*
* @param converterId converterId.
* @param currentLiteral literal to be used if converter is unrecognized or following converter if converterId
* contains extra characters.
* @param converterRegistry map of user-supported pattern converters keyed by format specifier, may be null.
* @param rules map of stock pattern converters keyed by format specifier.
* @param options converter options.
* @return converter or null.
*/
private static PatternConverter createConverter(final String converterId, final StringBuilder currentLiteral,
final Map converterRegistry, final Map rules, final List options) {
String converterName = converterId;
Object converterObj = null;
for (int i = converterId.length(); (i > 0) && (converterObj == null); i--) {
converterName = converterName.substring(0, i);
if (converterRegistry != null) {
converterObj = converterRegistry.get(converterName);
}
if ((converterObj == null) && (rules != null)) {
converterObj = rules.get(converterName);
}
}
if (converterObj == null) {
LogLog.error("Unrecognized format specifier [" + converterId + "]");
return null;
}
Class converterClass = null;
if (converterObj instanceof Class) {
converterClass = (Class) converterObj;
} else {
if (converterObj instanceof String) {
try {
converterClass = Loader.loadClass((String) converterObj);
} catch (ClassNotFoundException ex) {
LogLog.warn("Class for conversion pattern %" + converterName + " not found", ex);
return null;
}
} else {
LogLog.warn("Bad map entry for conversion pattern %" + converterName + ".");
return null;
}
}
try {
Method factory = converterClass.getMethod("newInstance",
new Class[] { Class.forName("[Ljava.lang.String;") });
String[] optionsArray = new String[options.size()];
optionsArray = (String[]) options.toArray(optionsArray);
Object newObj = factory.invoke(null, new Object[] { optionsArray });
if (newObj instanceof PatternConverter) {
currentLiteral.delete(0, currentLiteral.length() - (converterId.length() - converterName.length()));
return (PatternConverter) newObj;
} else {
LogLog.warn("Class " + converterClass.getName() + " does not extend PatternConverter.");
}
} catch (Exception ex) {
LogLog.error("Error creating converter for " + converterId, ex);
try {
//
// try default constructor
PatternConverter pc = (PatternConverter) converterClass.newInstance();
currentLiteral.delete(0, currentLiteral.length() - (converterId.length() - converterName.length()));
return pc;
} catch (Exception ex2) {
LogLog.error("Error creating converter for " + converterId, ex2);
}
}
return null;
}
/**
* Processes a format specifier sequence.
*
* @param c initial character of format specifier.
* @param pattern conversion pattern
* @param i current position in conversion pattern.
* @param currentLiteral current literal.
* @param formattingInfo current field specifier.
* @param converterRegistry map of user-provided pattern converters keyed by format specifier, may be null.
* @param rules map of stock pattern converters keyed by format specifier.
* @param patternConverters list to receive parsed pattern converter.
* @param formattingInfos list to receive corresponding field specifier.
* @return position after format specifier sequence.
*/
private static int finalizeConverter(char c, String pattern, int i, final StringBuilder currentLiteral,
final FormattingInfo formattingInfo, final Map converterRegistry, final Map rules,
final List patternConverters, final List formattingInfos) {
StringBuilder convBuf = new StringBuilder();
i = extractConverter(c, pattern, i, convBuf, currentLiteral);
String converterId = convBuf.toString();
List options = new ArrayList();
i = extractOptions(pattern, i, options);
PatternConverter pc = createConverter(converterId, currentLiteral, converterRegistry, rules, options);
if (pc == null) {
StringBuilder msg;
if ((converterId == null) || (converterId.length() == 0)) {
msg = new StringBuilder("Empty conversion specifier starting at position ");
} else {
msg = new StringBuilder("Unrecognized conversion specifier [");
msg.append(converterId);
msg.append("] starting at position ");
}
msg.append(Integer.toString(i));
msg.append(" in conversion pattern.");
LogLog.error(msg.toString());
patternConverters.add(new LiteralPatternConverter(currentLiteral.toString()));
formattingInfos.add(FormattingInfo.getDefault());
} else {
patternConverters.add(pc);
formattingInfos.add(formattingInfo);
if (currentLiteral.length() > 0) {
patternConverters.add(new LiteralPatternConverter(currentLiteral.toString()));
formattingInfos.add(FormattingInfo.getDefault());
}
}
currentLiteral.setLength(0);
return i;
}
/**
* The class wraps another Map but throws exceptions on any attempt to modify the map.
*/
private static class ReadOnlyMap implements Map {
/**
* Wrapped map.
*/
private final Map map;
/**
* Constructor
*
* @param src source map.
*/
public ReadOnlyMap(Map src) {
map = src;
}
/**
* {@inheritDoc}
*/
public void clear() {
throw new UnsupportedOperationException();
}
/**
* {@inheritDoc}
*/
public boolean containsKey(Object key) {
return map.containsKey(key);
}
/**
* {@inheritDoc}
*/
public boolean containsValue(Object value) {
return map.containsValue(value);
}
/**
* {@inheritDoc}
*/
public Set entrySet() {
return map.entrySet();
}
/**
* {@inheritDoc}
*/
public Object get(Object key) {
return map.get(key);
}
/**
* {@inheritDoc}
*/
public boolean isEmpty() {
return map.isEmpty();
}
/**
* {@inheritDoc}
*/
public Set keySet() {
return map.keySet();
}
/**
* {@inheritDoc}
*/
public Object put(Object key, Object value) {
throw new UnsupportedOperationException();
}
/**
* {@inheritDoc}
*/
public void putAll(Map t) {
throw new UnsupportedOperationException();
}
/**
* {@inheritDoc}
*/
public Object remove(Object key) {
throw new UnsupportedOperationException();
}
/**
* {@inheritDoc}
*/
public int size() {
return map.size();
}
/**
* {@inheritDoc}
*/
public Collection values() {
return map.values();
}
}
}