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 */
017package org.apache.logging.log4j.core.pattern;
018
019import java.util.List;
020import java.util.regex.Pattern;
021
022import org.apache.logging.log4j.core.LogEvent;
023import org.apache.logging.log4j.core.config.Configuration;
024import org.apache.logging.log4j.core.config.plugins.Plugin;
025import org.apache.logging.log4j.core.layout.PatternLayout;
026
027/**
028 * Replacement pattern converter.
029 */
030@Plugin(name = "replace", category = PatternConverter.CATEGORY)
031@ConverterKeys({ "replace" })
032public final class RegexReplacementConverter extends LogEventPatternConverter {
033
034    private final Pattern pattern;
035
036    private final String substitution;
037
038    private final List<PatternFormatter> formatters;
039
040    /**
041     * Construct the converter.
042     * @param formatters The PatternFormatters to generate the text to manipulate.
043     * @param pattern The regular expression Pattern.
044     * @param substitution The substitution string.
045     */
046    private RegexReplacementConverter(final List<PatternFormatter> formatters,
047                                      final Pattern pattern, final String substitution) {
048        super("replace", "replace");
049        this.pattern = pattern;
050        this.substitution = substitution;
051        this.formatters = formatters;
052    }
053
054    /**
055     * Gets an instance of the class.
056     *
057     * @param config The current Configuration.
058     * @param options pattern options, may be null.  If first element is "short",
059     *                only the first line of the throwable will be formatted.
060     * @return instance of class.
061     */
062    public static RegexReplacementConverter newInstance(final Configuration config, final String[] options) {
063        if (options.length != 3) {
064            LOGGER.error("Incorrect number of options on replace. Expected 3 received " + options.length);
065            return null;
066        }
067        if (options[0] == null) {
068            LOGGER.error("No pattern supplied on replace");
069            return null;
070        }
071        if (options[1] == null) {
072            LOGGER.error("No regular expression supplied on replace");
073            return null;
074        }
075        if (options[2] == null) {
076            LOGGER.error("No substitution supplied on replace");
077            return null;
078        }
079        final Pattern p = Pattern.compile(options[1]);
080        final PatternParser parser = PatternLayout.createPatternParser(config);
081        final List<PatternFormatter> formatters = parser.parse(options[0]);
082        return new RegexReplacementConverter(formatters, p, options[2]);
083    }
084
085
086    /**
087     * {@inheritDoc}
088     */
089    @Override
090    public void format(final LogEvent event, final StringBuilder toAppendTo) {
091        final StringBuilder buf = new StringBuilder();
092        for (final PatternFormatter formatter : formatters) {
093            formatter.format(event, buf);
094        }
095        toAppendTo.append(pattern.matcher(buf.toString()).replaceAll(substitution));
096    }
097}