/*
* 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.logging.log4j.core.pattern;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import org.apache.logging.log4j.Logger;
import org.apache.logging.log4j.core.config.Configuration;
import org.apache.logging.log4j.core.config.plugins.PluginManager;
import org.apache.logging.log4j.core.config.plugins.PluginType;
import org.apache.logging.log4j.core.helpers.Strings;
import org.apache.logging.log4j.status.StatusLogger;
/**
* Most of the work of the {@link org.apache.logging.log4j.core.layout.PatternLayout} 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}.
*/
public final class PatternParser {
/**
* Escape character for format specifier.
*/
private static final char ESCAPE_CHAR = '%';
/**
* The states the parser can be in while parsing the pattern.
*/
private enum ParserState {
/**
* Literal state.
*/
LITERAL_STATE,
/**
* In converter name state.
*/
CONVERTER_STATE,
/**
* Dot state.
*/
DOT_STATE,
/**
* Min state.
*/
MIN_STATE,
/**
* Max state.
*/
MAX_STATE;
}
private static final Logger LOGGER = StatusLogger.getLogger();
private static final int BUF_SIZE = 32;
private static final int DECIMAL = 10;
private final Configuration config;
private final Map<String, Class<PatternConverter>> converterRules;
/**
* Constructor.
* @param converterKey The type of converters that will be used.
*/
public PatternParser(final String converterKey) {
this(null, converterKey, null, null);
}
/**
* Constructor.
* @param config The current Configuration.
* @param converterKey The key to lookup the converters.
* @param expected The expected base Class of each Converter.
*/
public PatternParser(final Configuration config, final String converterKey, final Class<?> expected) {
this(config, converterKey, expected, null);
}
/**
* Constructor.
* @param config The current Configuration.
* @param converterKey The key to lookup the converters.
* @param expectedClass The expected base Class of each Converter.
* @param filterClass Filter the returned plugins after calling the plugin manager.
*/
public PatternParser(final Configuration config, final String converterKey, final Class<?> expectedClass,
final Class<?> filterClass) {
this.config = config;
final PluginManager manager = new PluginManager(converterKey, expectedClass);
manager.collectPlugins();
final Map<String, PluginType<?>> plugins = manager.getPlugins();
final Map<String, Class<PatternConverter>> converters = new HashMap<String, Class<PatternConverter>>();
for (final PluginType<?> type : plugins.values()) {
try {
@SuppressWarnings("unchecked")
final Class<PatternConverter> clazz = (Class<PatternConverter>)type.getPluginClass();
if (filterClass != null && !filterClass.isAssignableFrom(clazz)) {
continue;
}
final ConverterKeys keys = clazz.getAnnotation(ConverterKeys.class);
if (keys != null) {
for (final String key : keys.value()) {
converters.put(key, clazz);
}
}
} catch (final Exception ex) {
LOGGER.error("Error processing plugin " + type.getElementName(), ex);
}
}
converterRules = converters;
}
public List<PatternFormatter> parse(final String pattern) {
return parse(pattern, false);
}
public List<PatternFormatter> parse(final String pattern, final boolean alwaysWriteExceptions) {
final List<PatternFormatter> list = new ArrayList<PatternFormatter>();
final List<PatternConverter> converters = new ArrayList<PatternConverter>();
final List<FormattingInfo> fields = new ArrayList<FormattingInfo>();
parse(pattern, converters, fields);
final Iterator<FormattingInfo> fieldIter = fields.iterator();
boolean handlesThrowable = false;
for (final PatternConverter converter : converters) {
LogEventPatternConverter pc;
if (converter instanceof LogEventPatternConverter) {
pc = (LogEventPatternConverter) converter;
handlesThrowable |= pc.handlesThrowable();
} else {
pc = new LiteralPatternConverter(config, "");
}
FormattingInfo field;
if (fieldIter.hasNext()) {
field = fieldIter.next();
} else {
field = FormattingInfo.getDefault();
}
list.add(new PatternFormatter(pc, field));
}
if (alwaysWriteExceptions && !handlesThrowable) {
final LogEventPatternConverter pc = ExtendedThrowablePatternConverter.newInstance(null);
list.add(new PatternFormatter(pc, FormattingInfo.getDefault()));
}
return list;
}
/**
* 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(
final 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));
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(final String pattern, int i, final List<String> options) {
while (i < pattern.length() && pattern.charAt(i) == '{') {
final int begin = i++;
int end;
int depth = 0;
do {
end = pattern.indexOf('}', i);
if (end != -1) {
final int next = pattern.indexOf("{", i);
if (next != -1 && next < end) {
i = end + 1;
++depth;
} else if (depth > 0) {
--depth;
}
}
} while (depth > 0);
if (end == -1) {
break;
}
final String r = pattern.substring(begin + 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.
*/
public void parse(final String pattern, final List<PatternConverter> patternConverters,
final List<FormattingInfo> formattingInfos) {
if (pattern == null) {
throw new NullPointerException("pattern");
}
final StringBuilder currentLiteral = new StringBuilder(BUF_SIZE);
final int patternLength = pattern.length();
ParserState state = ParserState.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(config,
currentLiteral.toString()));
formattingInfos.add(FormattingInfo.getDefault());
}
currentLiteral.setLength(0);
currentLiteral.append(c); // append %
state = ParserState.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 = ParserState.DOT_STATE;
break;
default:
if (c >= '0' && c <= '9') {
formattingInfo = new FormattingInfo(formattingInfo.isLeftAligned(), c - '0',
formattingInfo.getMaxLength());
state = ParserState.MIN_STATE;
} else {
i = finalizeConverter(c, pattern, i, currentLiteral, formattingInfo,
converterRules, patternConverters, formattingInfos);
// Next pattern is assumed to be a literal.
state = ParserState.LITERAL_STATE;
formattingInfo = FormattingInfo.getDefault();
currentLiteral.setLength(0);
}
} // switch
break;
case MIN_STATE:
currentLiteral.append(c);
if (c >= '0' && c <= '9') {
// Multiply the existing value and add the value of the number just encountered.
formattingInfo = new FormattingInfo(formattingInfo.isLeftAligned(),
formattingInfo.getMinLength() * DECIMAL + c - '0',
formattingInfo.getMaxLength());
} else if (c == '.') {
state = ParserState.DOT_STATE;
} else {
i = finalizeConverter(c, pattern, i, currentLiteral, formattingInfo,
converterRules, patternConverters, formattingInfos);
state = ParserState.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 = ParserState.MAX_STATE;
} else {
LOGGER.error("Error occurred in position " + i
+ ".\n Was expecting digit, instead got char \"" + c + "\".");
state = ParserState.LITERAL_STATE;
}
break;
case MAX_STATE:
currentLiteral.append(c);
if (c >= '0' && c <= '9') {
// Multiply the existing value and add the value of the number just encountered.
formattingInfo = new FormattingInfo(
formattingInfo.isLeftAligned(), formattingInfo.getMinLength(),
formattingInfo.getMaxLength() * DECIMAL + c - '0');
} else {
i = finalizeConverter(c, pattern, i, currentLiteral, formattingInfo,
converterRules, patternConverters, formattingInfos);
state = ParserState.LITERAL_STATE;
formattingInfo = FormattingInfo.getDefault();
currentLiteral.setLength(0);
}
break;
} // switch
}
// while
if (currentLiteral.length() != 0) {
patternConverters.add(new LiteralPatternConverter(config, 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 rules map of stock pattern converters keyed by format specifier.
* @param options converter options.
* @return converter or null.
*/
private PatternConverter createConverter(final String converterId, final StringBuilder currentLiteral,
final Map<String, Class<PatternConverter>> rules,
final List<String> options) {
String converterName = converterId;
Class<PatternConverter> converterClass = null;
for (int i = converterId.length(); i > 0 && converterClass == null; i--) {
converterName = converterName.substring(0, i);
if (converterClass == null && rules != null) {
converterClass = rules.get(converterName);
}
}
if (converterClass == null) {
LOGGER.error("Unrecognized format specifier [" + converterId + "]");
return null;
}
// Work around the regression bug in Class.getDeclaredMethods() in Oracle Java in version > 1.6.0_17:
// http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6815786
final Method[] methods = converterClass.getDeclaredMethods();
Method newInstanceMethod = null;
for (final Method method : methods) {
if (Modifier.isStatic(method.getModifiers()) && method.getDeclaringClass().equals(converterClass) &&
method.getName().equals("newInstance")) {
if (newInstanceMethod == null) {
newInstanceMethod = method;
} else if (method.getReturnType().equals(newInstanceMethod.getReturnType())) {
LOGGER.error("Class " + converterClass + " cannot contain multiple static newInstance methods");
return null;
}
}
}
if (newInstanceMethod == null) {
LOGGER.error("Class " + converterClass + " does not contain a static newInstance method");
return null;
}
final Class<?>[] parmTypes = newInstanceMethod.getParameterTypes();
final Object [] parms = parmTypes.length > 0 ? new Object[parmTypes.length] : null;
if (parms != null) {
int i = 0;
boolean errors = false;
for (final Class<?> clazz : parmTypes) {
if (clazz.isArray() && clazz.getName().equals("[Ljava.lang.String;")) {
final String[] optionsArray = options.toArray(new String[options.size()]);
parms[i] = optionsArray;
} else if (clazz.isAssignableFrom(Configuration.class)) {
parms[i] = config;
} else {
LOGGER.error("Unknown parameter type " + clazz.getName() + " for static newInstance method of " +
converterClass.getName());
errors = true;
}
++i;
}
if (errors) {
return null;
}
}
try {
final Object newObj = newInstanceMethod.invoke(null, parms);
if (newObj instanceof PatternConverter) {
currentLiteral.delete(0, currentLiteral.length()
- (converterId.length() - converterName.length()));
return (PatternConverter) newObj;
} else {
LOGGER.warn("Class " + converterClass.getName() + " does not extend PatternConverter.");
}
} catch (final Exception ex) {
LOGGER.error("Error creating converter for " + converterId, ex);
}
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 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 int finalizeConverter(final char c, final String pattern, int i,
final StringBuilder currentLiteral, final FormattingInfo formattingInfo,
final Map<String, Class<PatternConverter>> rules,
final List<PatternConverter> patternConverters, final List<FormattingInfo> formattingInfos) {
final StringBuilder convBuf = new StringBuilder();
i = extractConverter(c, pattern, i, convBuf, currentLiteral);
final String converterId = convBuf.toString();
final List<String> options = new ArrayList<String>();
i = extractOptions(pattern, i, options);
final PatternConverter pc = createConverter(converterId, currentLiteral, rules, options);
if (pc == null) {
StringBuilder msg;
if (Strings.isEmpty(converterId)) {
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.");
LOGGER.error(msg.toString());
patternConverters.add(new LiteralPatternConverter(config, currentLiteral.toString()));
formattingInfos.add(FormattingInfo.getDefault());
} else {
patternConverters.add(pc);
formattingInfos.add(formattingInfo);
if (currentLiteral.length() > 0) {
patternConverters.add(new LiteralPatternConverter(config, currentLiteral.toString()));
formattingInfos.add(FormattingInfo.getDefault());
}
}
currentLiteral.setLength(0);
return i;
}
}