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 */
017 package org.apache.logging.log4j.core.pattern;
018
019 import java.util.List;
020
021 import org.apache.logging.log4j.core.LogEvent;
022 import org.apache.logging.log4j.core.config.Configuration;
023 import org.apache.logging.log4j.core.config.plugins.Plugin;
024 import org.apache.logging.log4j.core.layout.PatternLayout;
025 import org.apache.logging.log4j.core.util.Patterns;
026
027 /**
028 * Style pattern converter. Adds ANSI color styling to the result of the enclosed pattern.
029 */
030 @Plugin(name = "style", category = PatternConverter.CATEGORY)
031 @ConverterKeys({ "style" })
032 public final class StyleConverter extends LogEventPatternConverter implements AnsiConverter {
033
034 /**
035 * Gets an instance of the class.
036 *
037 * @param config
038 * The current Configuration.
039 * @param options
040 * pattern options, may be null. If first element is "short", only the first line of the throwable will
041 * be formatted.
042 * @return instance of class.
043 */
044 public static StyleConverter newInstance(final Configuration config, final String[] options) {
045 if (options.length < 1) {
046 LOGGER.error("Incorrect number of options on style. Expected at least 1, received " + options.length);
047 return null;
048 }
049 if (options[0] == null) {
050 LOGGER.error("No pattern supplied on style");
051 return null;
052 }
053 if (options[1] == null) {
054 LOGGER.error("No style attributes provided");
055 return null;
056 }
057 final PatternParser parser = PatternLayout.createPatternParser(config);
058 final List<PatternFormatter> formatters = parser.parse(options[0]);
059 final String style = AnsiEscape.createSequence(options[1].split(Patterns.COMMA_SEPARATOR));
060 final boolean noConsoleNoAnsi = options.length > 2
061 && (PatternParser.NO_CONSOLE_NO_ANSI + "=true").equals(options[2]);
062 final boolean hideAnsi = noConsoleNoAnsi && System.console() == null;
063 return new StyleConverter(formatters, style, hideAnsi);
064 }
065
066 private final List<PatternFormatter> patternFormatters;
067
068 private final boolean noAnsi;
069
070 private final String style;
071
072 private final String defaultStyle;
073
074 /**
075 * Constructs the converter.
076 *
077 * @param patternFormatters
078 * The PatternFormatters to generate the text to manipulate.
079 * @param style
080 * The style that should encapsulate the pattern.
081 * @param noAnsi
082 * If true, do not output ANSI escape codes.
083 */
084 private StyleConverter(final List<PatternFormatter> patternFormatters, final String style, final boolean noAnsi) {
085 super("style", "style");
086 this.patternFormatters = patternFormatters;
087 this.style = style;
088 this.defaultStyle = AnsiEscape.getDefaultStyle();
089 this.noAnsi = noAnsi;
090 }
091
092 /**
093 * {@inheritDoc}
094 */
095 @Override
096 public void format(final LogEvent event, final StringBuilder toAppendTo) {
097 final StringBuilder buf = new StringBuilder();
098 for (final PatternFormatter formatter : patternFormatters) {
099 formatter.format(event, buf);
100 }
101
102 if (buf.length() > 0) {
103 if (noAnsi) {
104 // faster to test and do this than setting style and defaultStyle to empty strings.
105 toAppendTo.append(buf.toString());
106 } else {
107 toAppendTo.append(style).append(buf.toString()).append(defaultStyle);
108 }
109 }
110 }
111
112 @Override
113 public boolean handlesThrowable() {
114 for (final PatternFormatter formatter : patternFormatters) {
115 if (formatter.handlesThrowable()) {
116 return true;
117 }
118 }
119 return false;
120 }
121
122 /**
123 * Returns a String suitable for debugging.
124 *
125 * @return a String suitable for debugging.
126 */
127 @Override
128 public String toString() {
129 final StringBuilder sb = new StringBuilder();
130 sb.append(super.toString());
131 sb.append("[style=");
132 sb.append(style);
133 sb.append(", defaultStyle=");
134 sb.append(defaultStyle);
135 sb.append(", patternFormatters=");
136 sb.append(patternFormatters);
137 sb.append(", noAnsi=");
138 sb.append(noAnsi);
139 sb.append(']');
140 return sb.toString();
141 }
142
143 }