org.apache.logging.log4j.core.layout.PatternLayout Maven / Gradle / Ivy
/*
* 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.layout;
import java.nio.charset.Charset;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.apache.logging.log4j.core.Layout;
import org.apache.logging.log4j.core.LogEvent;
import org.apache.logging.log4j.core.config.Configuration;
import org.apache.logging.log4j.core.config.DefaultConfiguration;
import org.apache.logging.log4j.core.config.Node;
import org.apache.logging.log4j.core.config.plugins.Plugin;
import org.apache.logging.log4j.core.config.plugins.PluginAttribute;
import org.apache.logging.log4j.core.config.plugins.PluginBuilderAttribute;
import org.apache.logging.log4j.core.config.plugins.PluginBuilderFactory;
import org.apache.logging.log4j.core.config.plugins.PluginConfiguration;
import org.apache.logging.log4j.core.config.plugins.PluginElement;
import org.apache.logging.log4j.core.config.plugins.PluginFactory;
import org.apache.logging.log4j.core.pattern.LogEventPatternConverter;
import org.apache.logging.log4j.core.pattern.PatternFormatter;
import org.apache.logging.log4j.core.pattern.PatternParser;
import org.apache.logging.log4j.core.pattern.RegexReplacement;
/**
* A flexible layout configurable with pattern string.
*
* The goal of this class is to {@link org.apache.logging.log4j.core.Layout#toByteArray format} a {@link LogEvent} and
* return the results. The format of the result depends on the conversion pattern.
*
*
* 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 conversion specifiers.
*
*
* See the Log4j Manual for details on the supported pattern converters.
*
*/
@Plugin(name = "PatternLayout", category = Node.CATEGORY, elementType = Layout.ELEMENT_TYPE, printObject = true)
public final class PatternLayout extends AbstractStringLayout {
private static final long serialVersionUID = 1L;
/**
* Default pattern string for log output. Currently set to the
* string "%m%n" 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 %r [%t] %p %c %x - %m%n.
*/
public static final String TTCC_CONVERSION_PATTERN =
"%r [%t] %p %c %x - %m%n";
/**
* A simple pattern.
* Current value is %d [%t] %p %c - %m%n.
*/
public static final String SIMPLE_CONVERSION_PATTERN =
"%d [%t] %p %c - %m%n";
/** Key to identify pattern converters. */
public static final String KEY = "Converter";
/**
* Initial converter for pattern.
*/
private final List formatters;
/**
* Conversion pattern.
*/
private final String conversionPattern;
/**
* The current Configuration.
*/
private final Configuration config;
private final RegexReplacement replace;
private final boolean alwaysWriteExceptions;
private final boolean noConsoleNoAnsi;
/**
* Constructs a EnhancedPatternLayout using the supplied conversion pattern.
*
* @param config The Configuration.
* @param replace The regular expression to match.
* @param pattern conversion pattern.
* @param charset The character set.
* @param alwaysWriteExceptions Whether or not exceptions should always be handled in this pattern (if {@code true},
* exceptions will be written even if the pattern does not specify so).
* @param noConsoleNoAnsi
* If {@code "true"} (default) and {@link System#console()} is null, do not output ANSI escape codes
* @param header
*/
private PatternLayout(final Configuration config, final RegexReplacement replace, final String pattern,
final Charset charset, final boolean alwaysWriteExceptions, final boolean noConsoleNoAnsi,
final String header, final String footer) {
super(charset, toBytes(header, charset), toBytes(footer, charset));
this.replace = replace;
this.conversionPattern = pattern;
this.config = config;
this.alwaysWriteExceptions = alwaysWriteExceptions;
this.noConsoleNoAnsi = noConsoleNoAnsi;
final PatternParser parser = createPatternParser(config);
this.formatters = parser.parse(pattern == null ? DEFAULT_CONVERSION_PATTERN : pattern, this.alwaysWriteExceptions, this.noConsoleNoAnsi);
}
private static byte[] toBytes(final String str, final Charset charset) {
if (str != null) {
return str.getBytes(charset != null ? charset : Charset.defaultCharset());
}
return null;
}
private byte[] strSubstitutorReplace(final byte... b) {
if (b != null && config != null) {
return getBytes(config.getStrSubstitutor().replace(new String(b, getCharset())));
}
return b;
}
@Override
public byte[] getHeader() {
return strSubstitutorReplace(super.getHeader());
}
@Override
public byte[] getFooter() {
return strSubstitutorReplace(super.getFooter());
}
/**
* Gets the conversion pattern.
*
* @return the conversion pattern.
*/
public String getConversionPattern() {
return conversionPattern;
}
/**
* Gets this PatternLayout's content format. Specified by:
*
* - Key: "structured" Value: "false"
* - Key: "formatType" Value: "conversion" (format uses the keywords supported by OptionConverter)
* - Key: "format" Value: provided "conversionPattern" param
*
*
* @return Map of content format keys supporting PatternLayout
*/
@Override
public Map getContentFormat()
{
final Map result = new HashMap();
result.put("structured", "false");
result.put("formatType", "conversion");
result.put("format", conversionPattern);
return result;
}
/**
* Formats a logging event to a writer.
*
*
* @param event logging event to be formatted.
* @return The event formatted as a String.
*/
@Override
public String toSerializable(final LogEvent event) {
final StringBuilder buf = new StringBuilder();
for (final PatternFormatter formatter : formatters) {
formatter.format(event, buf);
}
String str = buf.toString();
if (replace != null) {
str = replace.format(str);
}
return str;
}
/**
* Create a PatternParser.
* @param config The Configuration.
* @return The PatternParser.
*/
public static PatternParser createPatternParser(final Configuration config) {
if (config == null) {
return new PatternParser(config, KEY, LogEventPatternConverter.class);
}
PatternParser parser = config.getComponent(KEY);
if (parser == null) {
parser = new PatternParser(config, KEY, LogEventPatternConverter.class);
config.addComponent(KEY, parser);
parser = (PatternParser) config.getComponent(KEY);
}
return parser;
}
@Override
public String toString() {
return conversionPattern;
}
/**
* Create a pattern layout.
*
* @param pattern
* The pattern. If not specified, defaults to DEFAULT_CONVERSION_PATTERN.
* @param config
* The Configuration. Some Converters require access to the Interpolator.
* @param replace
* A Regex replacement String.
* @param charset
* The character set.
* @param alwaysWriteExceptions
* If {@code "true"} (default) exceptions are always written even if the pattern contains no exception tokens.
* @param noConsoleNoAnsi
* If {@code "true"} (default is false) and {@link System#console()} is null, do not output ANSI escape codes
* @param header
* The footer to place at the top of the document, once.
* @param footer
* The footer to place at the bottom of the document, once.
* @return The PatternLayout.
*/
@PluginFactory
public static PatternLayout createLayout(
@PluginAttribute(value = "pattern", defaultString = DEFAULT_CONVERSION_PATTERN) final String pattern,
@PluginConfiguration final Configuration config,
@PluginElement("Replace") final RegexReplacement replace,
@PluginAttribute(value = "charset", defaultString = "UTF-8") final Charset charset,
@PluginAttribute(value = "alwaysWriteExceptions", defaultBoolean = true) final boolean alwaysWriteExceptions,
@PluginAttribute(value = "noConsoleNoAnsi", defaultBoolean = false) final boolean noConsoleNoAnsi,
@PluginAttribute("header") final String header,
@PluginAttribute("footer") final String footer) {
return newBuilder()
.withPattern(pattern)
.withConfiguration(config)
.withRegexReplacement(replace)
.withCharset(charset)
.withAlwaysWriteExceptions(alwaysWriteExceptions)
.withNoConsoleNoAnsi(noConsoleNoAnsi)
.withHeader(header)
.withFooter(footer)
.build();
}
/**
* Creates a PatternLayout using the default options. These options include using UTF-8, the default conversion
* pattern, exceptions being written, and with ANSI escape codes.
*
* @return the PatternLayout.
* @see #DEFAULT_CONVERSION_PATTERN Default conversion pattern
*/
public static PatternLayout createDefaultLayout() {
return newBuilder().build();
}
/**
* Creates a builder for a custom PatternLayout.
* @return a PatternLayout builder.
*/
@PluginBuilderFactory
public static Builder newBuilder() {
return new Builder();
}
/**
* Custom PatternLayout builder. Use the {@link PatternLayout#newBuilder() builder factory method} to create this.
*/
public static class Builder implements org.apache.logging.log4j.core.util.Builder {
// FIXME: it seems rather redundant to repeat default values (same goes for field names)
// perhaps introduce a @PluginBuilderAttribute that has no values of its own and uses reflection?
@PluginBuilderAttribute
private String pattern = PatternLayout.DEFAULT_CONVERSION_PATTERN;
@PluginConfiguration
private Configuration configuration = null;
@PluginElement("Replace")
private RegexReplacement regexReplacement = null;
// LOG4J2-783 use platform default by default
@PluginBuilderAttribute
private Charset charset = Charset.defaultCharset();
@PluginBuilderAttribute
private boolean alwaysWriteExceptions = true;
@PluginBuilderAttribute
private boolean noConsoleNoAnsi = false;
@PluginBuilderAttribute
private String header = null;
@PluginBuilderAttribute
private String footer = null;
private Builder() {
}
// TODO: move javadocs from PluginFactory to here
public Builder withPattern(final String pattern) {
this.pattern = pattern;
return this;
}
public Builder withConfiguration(final Configuration configuration) {
this.configuration = configuration;
return this;
}
public Builder withRegexReplacement(final RegexReplacement regexReplacement) {
this.regexReplacement = regexReplacement;
return this;
}
public Builder withCharset(final Charset charset) {
this.charset = charset;
return this;
}
public Builder withAlwaysWriteExceptions(final boolean alwaysWriteExceptions) {
this.alwaysWriteExceptions = alwaysWriteExceptions;
return this;
}
public Builder withNoConsoleNoAnsi(final boolean noConsoleNoAnsi) {
this.noConsoleNoAnsi = noConsoleNoAnsi;
return this;
}
public Builder withHeader(final String header) {
this.header = header;
return this;
}
public Builder withFooter(final String footer) {
this.footer = footer;
return this;
}
@Override
public PatternLayout build() {
// fall back to DefaultConfiguration
if (configuration == null) {
configuration = new DefaultConfiguration();
}
return new PatternLayout(configuration, regexReplacement, pattern, charset, alwaysWriteExceptions,
noConsoleNoAnsi, header, footer);
}
}
}