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    /**
020     * Interface that all PatternConverters must implement.
021     */
022    public interface PatternConverter {
023    
024        /**
025         * Main plugin category for PatternConverter plugins.
026         *
027         * @since 2.1
028         */
029        String CATEGORY = "Converter";
030    
031        /**
032         * Formats an object into a string buffer.
033         *
034         * @param obj        event to format, may not be null.
035         * @param toAppendTo string buffer to which the formatted event will be appended.  May not be null.
036         */
037        void format(Object obj, StringBuilder toAppendTo);
038    
039        /**
040         * Returns the name of the converter.
041         * @return The name of the converter.
042         */
043        String getName();
044    
045        /**
046         * This method returns the CSS style class that should be applied to
047         * the LoggingEvent passed as parameter, which can be null.
048         *
049         * @param e null values are accepted
050         * @return the name of the conversion pattern
051         */
052        String getStyleClass(Object e);
053    }