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 java.util.List; 020 021import org.apache.logging.log4j.core.LogEvent; 022import org.apache.logging.log4j.core.config.Configuration; 023import org.apache.logging.log4j.core.config.plugins.Plugin; 024import org.apache.logging.log4j.core.layout.PatternLayout; 025import org.apache.logging.log4j.util.PerformanceSensitive; 026 027/** 028 * VariablesNotEmpty pattern converter. 029 */ 030@Plugin(name = "notEmpty", category = PatternConverter.CATEGORY) 031@ConverterKeys({ "notEmpty", "varsNotEmpty", "variablesNotEmpty", }) 032@PerformanceSensitive("allocation") 033public final class VariablesNotEmptyReplacementConverter extends LogEventPatternConverter { 034 035 private final List<PatternFormatter> formatters; 036 037 /** 038 * Constructs the converter. 039 * 040 * @param formatters 041 * The PatternFormatters to generate the text to manipulate. 042 */ 043 private VariablesNotEmptyReplacementConverter(final List<PatternFormatter> formatters) { 044 super("notEmpty", "notEmpty"); 045 this.formatters = formatters; 046 } 047 048 /** 049 * Gets an instance of the class. 050 * 051 * @param config 052 * The current Configuration. 053 * @param options 054 * pattern options, may be null. 055 * @return instance of class. 056 */ 057 public static VariablesNotEmptyReplacementConverter newInstance(final Configuration config, 058 final String[] options) { 059 if (options.length != 1) { 060 LOGGER.error("Incorrect number of options on varsNotEmpty. Expected 1 received " + options.length); 061 return null; 062 } 063 if (options[0] == null) { 064 LOGGER.error("No pattern supplied on varsNotEmpty"); 065 return null; 066 } 067 final PatternParser parser = PatternLayout.createPatternParser(config); 068 final List<PatternFormatter> formatters = parser.parse(options[0]); 069 return new VariablesNotEmptyReplacementConverter(formatters); 070 } 071 072 /** 073 * {@inheritDoc} 074 */ 075 @Override 076 public void format(final LogEvent event, final StringBuilder toAppendTo) { 077 final int start = toAppendTo.length(); 078 boolean allVarsEmpty = true; 079 boolean hasVars = false; 080 for (int i = 0; i < formatters.size(); i++) { 081 final PatternFormatter formatter = formatters.get(i); 082 final int formatterStart = toAppendTo.length(); 083 formatter.format(event, toAppendTo); 084 if (formatter.getConverter().isVariable()) { 085 hasVars = true; 086 allVarsEmpty = allVarsEmpty && (toAppendTo.length() == formatterStart); 087 } 088 } 089 if (!hasVars || allVarsEmpty) { 090 toAppendTo.setLength(start); // remove formatter results 091 } 092 } 093}