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 org.apache.logging.log4j.core.LogEvent; 020import org.apache.logging.log4j.core.impl.LocationAware; 021 022/** 023 * 024 */ 025public class PatternFormatter { 026 private final LogEventPatternConverter converter; 027 private final FormattingInfo field; 028 private final boolean skipFormattingInfo; 029 030 public PatternFormatter(final LogEventPatternConverter converter, final FormattingInfo field) { 031 this.converter = converter; 032 this.field = field; 033 this.skipFormattingInfo = field == FormattingInfo.getDefault(); 034 } 035 036 public void format(final LogEvent event, final StringBuilder buf) { 037 if (skipFormattingInfo) { 038 converter.format(event, buf); 039 } else { 040 formatWithInfo(event, buf); 041 } 042 } 043 private void formatWithInfo(final LogEvent event, final StringBuilder buf) { 044 final int startField = buf.length(); 045 converter.format(event, buf); 046 field.format(startField, buf); 047 } 048 049 public LogEventPatternConverter getConverter() { 050 return converter; 051 } 052 053 public FormattingInfo getFormattingInfo() { 054 return field; 055 } 056 057 /** 058 * Normally pattern formatters are not meant to handle Exceptions although few pattern formatters might. 059 * <p> 060 * By examining the return values for this method, the containing layout will determine whether it handles 061 * throwables or not. 062 * </p> 063 * 064 * @return true if this PatternConverter handles throwables 065 */ 066 public boolean handlesThrowable() { 067 return converter.handlesThrowable(); 068 } 069 070 /** 071 * Most pattern formatters do not use location information. When they do they should return true here 072 * so that the logging system can efficiently capture it. 073 * @return true if location information is required. 074 */ 075 public boolean requiresLocation() { 076 return converter instanceof LocationAware && ((LocationAware) converter).requiresLocation(); 077 } 078 079 /** 080 * Returns a String suitable for debugging. 081 * 082 * @return a String suitable for debugging. 083 */ 084 @Override 085 public String toString() { 086 final StringBuilder sb = new StringBuilder(); 087 sb.append(super.toString()); 088 sb.append("[converter="); 089 sb.append(converter); 090 sb.append(", field="); 091 sb.append(field); 092 sb.append(']'); 093 return sb.toString(); 094 } 095}