2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
9 * http://www.apache.org/licenses/LICENSE-2.0
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
18 package org.apache.log4j.pattern;
20 import org.apache.log4j.spi.LoggingEvent;
24 * LoggingEventPatternConverter is a base class for pattern converters
25 * that can format information from instances of LoggingEvent.
30 public abstract class LoggingEventPatternConverter extends PatternConverter {
32 * Constructs an instance of LoggingEventPatternConverter.
33 * @param name name of converter.
34 * @param style CSS style for output.
36 protected LoggingEventPatternConverter(
37 final String name, final String style) {
42 * Formats an event into a string buffer.
43 * @param event event to format, may not be null.
44 * @param toAppendTo string buffer to which the formatted event will be appended. May not be null.
46 public abstract void format(
47 final LoggingEvent event, final StringBuffer toAppendTo);
52 public void format(final Object obj, final StringBuffer output) {
53 if (obj instanceof LoggingEvent) {
54 format((LoggingEvent) obj, output);
59 * Normally pattern converters are not meant to handle Exceptions although
60 * few pattern converters might.
62 * By examining the return values for this method, the containing layout will
63 * determine whether it handles throwables or not.
65 * @return true if this PatternConverter handles throwables
67 public boolean handlesThrowable() {