    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 org.apache.logging.log4j.core.LogEvent;
    020    import org.apache.logging.log4j.core.config.Configuration;
    021    import org.apache.logging.log4j.core.util.OptionConverter;
    022
    023
    024    /**
    025     * Formats a string literal.
    026     */
    027    public final class LiteralPatternConverter extends LogEventPatternConverter implements ArrayPatternConverter {
    028        /**
    029         * String literal.
    030         */
    031        private final String literal;
    032
    033        private final Configuration config;
    034
    035        private final boolean substitute;
    036
    037        /**
    038         * Create a new instance.
    039         *
    040         * @param config The Configuration.
    041         * @param literal string literal.
    042         * @param convertBackslashes if {@code true}, backslash characters are treated as escape characters and character
    043         *            sequences like "\" followed by "t" (backslash+t) are converted to special characters like '\t' (tab).
    044         */
    045        public LiteralPatternConverter(final Configuration config, final String literal, final boolean convertBackslashes) {
    046            super("Literal", "literal");
    047            this.literal = convertBackslashes ? OptionConverter.convertSpecialChars(literal) : literal; // LOG4J2-829
    048            this.config = config;
    049            substitute = config != null && literal.contains("${");
    050        }
    051
    052        /**
    053         * {@inheritDoc}
    054         */
    055        @Override
    056        public void format(final LogEvent event, final StringBuilder toAppendTo) {
    057            toAppendTo.append(substitute ? config.getStrSubstitutor().replace(event, literal) : literal);
    058        }
    059
    060        /**
    061         * {@inheritDoc}
    062         */
    063        @Override
    064        public void format(final Object obj, final StringBuilder output) {
    065            output.append(substitute ? config.getStrSubstitutor().replace(literal) : literal);
    066        }
    067
    068        /**
    069         * {@inheritDoc}
    070         */
    071        @Override
    072        public void format(final StringBuilder output, final Object... objects) {
    073            output.append(substitute ? config.getStrSubstitutor().replace(literal) : literal);
    074        }
    075
    076        public String getLiteral() {
    077            return literal;
    078        }
    079    }