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         * Formats an object into a string buffer.
025         *
026         * @param obj        event to format, may not be null.
027         * @param toAppendTo string buffer to which the formatted event will be appended.  May not be null.
028         */
029        void format(Object obj, StringBuilder toAppendTo);
030    
031        /**
032         * Returns the name of the converter.
033         * @return The name of the converter.
034         */
035        String getName();
036    
037        /**
038         * This method returns the CSS style class that should be applied to
039         * the LoggingEvent passed as parameter, which can be null.
040         * <p/>
041         *
042         * @param e null values are accepted
043         * @return the name of the conversion pattern
044         */
045        String getStyleClass(Object e);
046    }