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.layout; 018 019import java.net.InetAddress; 020import java.net.UnknownHostException; 021import java.nio.charset.Charset; 022import java.text.SimpleDateFormat; 023import java.util.Date; 024import java.util.HashMap; 025import java.util.Locale; 026import java.util.Map; 027import java.util.regex.Matcher; 028import java.util.regex.Pattern; 029 030import org.apache.logging.log4j.core.LogEvent; 031import org.apache.logging.log4j.core.config.plugins.Plugin; 032import org.apache.logging.log4j.core.config.plugins.PluginAttribute; 033import org.apache.logging.log4j.core.config.plugins.PluginFactory; 034import org.apache.logging.log4j.core.helpers.Charsets; 035import org.apache.logging.log4j.core.net.Facility; 036import org.apache.logging.log4j.core.net.Priority; 037 038 039/** 040 * Formats a log event as a BSD Log record. 041 */ 042@Plugin(name = "SyslogLayout", category = "Core", elementType = "layout", printObject = true) 043public class SyslogLayout extends AbstractStringLayout { 044 /** 045 * Match newlines in a platform-independent manner. 046 */ 047 public static final Pattern NEWLINE_PATTERN = Pattern.compile("\\r?\\n"); 048 049 private final Facility facility; 050 private final boolean includeNewLine; 051 private final String escapeNewLine; 052 053 /** 054 * Date format used if header = true. 055 */ 056 private final SimpleDateFormat dateFormat = new SimpleDateFormat("MMM dd HH:mm:ss ", Locale.ENGLISH); 057 /** 058 * Host name used to identify messages from this appender. 059 */ 060 private final String localHostname = getLocalHostname(); 061 062 063 064 protected SyslogLayout(final Facility facility, final boolean includeNL, final String escapeNL, final Charset charset) { 065 super(charset); 066 this.facility = facility; 067 this.includeNewLine = includeNL; 068 this.escapeNewLine = escapeNL == null ? null : Matcher.quoteReplacement(escapeNL); 069 } 070 071 /** 072 * Formats a {@link org.apache.logging.log4j.core.LogEvent} in conformance with the BSD Log record format. 073 * 074 * @param event The LogEvent 075 * @return the event formatted as a String. 076 */ 077 @Override 078 public String toSerializable(final LogEvent event) { 079 final StringBuilder buf = new StringBuilder(); 080 081 buf.append("<"); 082 buf.append(Priority.getPriority(facility, event.getLevel())); 083 buf.append(">"); 084 addDate(event.getMillis(), buf); 085 buf.append(" "); 086 buf.append(localHostname); 087 buf.append(" "); 088 089 String message = event.getMessage().getFormattedMessage(); 090 if (null != escapeNewLine) { 091 message = NEWLINE_PATTERN.matcher(message).replaceAll(escapeNewLine); 092 } 093 buf.append(message); 094 095 if (includeNewLine) { 096 buf.append("\n"); 097 } 098 return buf.toString(); 099 } 100 101 /** 102 * This method gets the network name of the machine we are running on. 103 * Returns "UNKNOWN_LOCALHOST" in the unlikely case where the host name 104 * cannot be found. 105 * 106 * @return String the name of the local host 107 */ 108 private String getLocalHostname() { 109 try { 110 final InetAddress addr = InetAddress.getLocalHost(); 111 return addr.getHostName(); 112 } catch (final UnknownHostException uhe) { 113 LOGGER.error("Could not determine local host name", uhe); 114 return "UNKNOWN_LOCALHOST"; 115 } 116 } 117 118 private synchronized void addDate(final long timestamp, final StringBuilder buf) { 119 final int index = buf.length() + 4; 120 buf.append(dateFormat.format(new Date(timestamp))); 121 // RFC 3164 says leading space, not leading zero on days 1-9 122 if (buf.charAt(index) == '0') { 123 buf.setCharAt(index, ' '); 124 } 125 } 126 127 /** 128 * SyslogLayout's content format is specified by:<p/> 129 * Key: "structured" Value: "false"<p/> 130 * Key: "dateFormat" Value: "MMM dd HH:mm:ss "<p/> 131 * Key: "format" Value: "<LEVEL>TIMESTAMP PROP(HOSTNAME) MESSAGE"<p/> 132 * Key: "formatType" Value: "logfilepatternreceiver" (format uses the keywords supported by LogFilePatternReceiver) 133 * @return Map of content format keys supporting SyslogLayout 134 */ 135 @Override 136 public Map<String, String> getContentFormat() 137 { 138 final Map<String, String> result = new HashMap<String, String>(); 139 result.put("structured", "false"); 140 result.put("formatType", "logfilepatternreceiver"); 141 result.put("dateFormat", dateFormat.toPattern()); 142 result.put("format", "<LEVEL>TIMESTAMP PROP(HOSTNAME) MESSAGE"); 143 return result; 144 } 145 146 /** 147 * Create a SyslogLayout. 148 * @param facility The Facility is used to try to classify the message. 149 * @param includeNL If true a newline will be appended to the result. 150 * @param escapeNL Pattern to use for replacing newlines. 151 * @param charsetName The character set. 152 * @return A SyslogLayout. 153 */ 154 @PluginFactory 155 public static SyslogLayout createLayout( 156 @PluginAttribute("facility") final String facility, 157 @PluginAttribute("newLine") final String includeNL, 158 @PluginAttribute("newLineEscape") final String escapeNL, 159 @PluginAttribute("charset") final String charsetName) { 160 final Charset charset = Charsets.getSupportedCharset(charsetName); 161 final boolean includeNewLine = Boolean.parseBoolean(includeNL); 162 final Facility f = Facility.toFacility(facility, Facility.LOCAL0); 163 return new SyslogLayout(f, includeNewLine, escapeNL, charset); 164 } 165}