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.layout;
018    
019    import java.nio.charset.Charset;
020    import java.text.SimpleDateFormat;
021    import java.util.Date;
022    import java.util.HashMap;
023    import java.util.Locale;
024    import java.util.Map;
025    import java.util.regex.Matcher;
026    import java.util.regex.Pattern;
027    
028    import org.apache.logging.log4j.core.LogEvent;
029    import org.apache.logging.log4j.core.config.plugins.Plugin;
030    import org.apache.logging.log4j.core.config.plugins.PluginAttribute;
031    import org.apache.logging.log4j.core.config.plugins.PluginFactory;
032    import org.apache.logging.log4j.core.net.Facility;
033    import org.apache.logging.log4j.core.net.Priority;
034    import org.apache.logging.log4j.core.util.NetUtils;
035    
036    
037    /**
038     * Formats a log event as a BSD Log record.
039     */
040    @Plugin(name = "SyslogLayout", category = "Core", elementType = "layout", printObject = true)
041    public final class SyslogLayout extends AbstractStringLayout {
042        /**
043         * Match newlines in a platform-independent manner.
044         */
045        public static final Pattern NEWLINE_PATTERN = Pattern.compile("\\r?\\n");
046    
047        private final Facility facility;
048        private final boolean includeNewLine;
049        private final String escapeNewLine;
050    
051        /**
052         * Date format used if header = true.
053         */
054        private final SimpleDateFormat dateFormat = new SimpleDateFormat("MMM dd HH:mm:ss ", Locale.ENGLISH);
055        /**
056         * Host name used to identify messages from this appender.
057         */
058        private final String localHostname = NetUtils.getLocalHostname();
059    
060    
061    
062        protected SyslogLayout(final Facility facility, final boolean includeNL, final String escapeNL, final Charset charset) {
063            super(charset);
064            this.facility = facility;
065            this.includeNewLine = includeNL;
066            this.escapeNewLine = escapeNL == null ? null : Matcher.quoteReplacement(escapeNL);
067        }
068    
069        /**
070         * Formats a {@link org.apache.logging.log4j.core.LogEvent} in conformance with the BSD Log record format.
071         *
072         * @param event The LogEvent
073         * @return the event formatted as a String.
074         */
075        @Override
076        public String toSerializable(final LogEvent event) {
077            final StringBuilder buf = new StringBuilder();
078    
079            buf.append('<');
080            buf.append(Priority.getPriority(facility, event.getLevel()));
081            buf.append('>');
082            addDate(event.getTimeMillis(), buf);
083            buf.append(' ');
084            buf.append(localHostname);
085            buf.append(' ');
086    
087            String message = event.getMessage().getFormattedMessage();
088            if (null != escapeNewLine) {
089                message = NEWLINE_PATTERN.matcher(message).replaceAll(escapeNewLine);
090            }
091            buf.append(message);
092    
093            if (includeNewLine) {
094                buf.append('\n');
095            }
096            return buf.toString();
097        }
098    
099        private synchronized void addDate(final long timestamp, final StringBuilder buf) {
100            final int index = buf.length() + 4;
101            buf.append(dateFormat.format(new Date(timestamp)));
102            //  RFC 3164 says leading space, not leading zero on days 1-9
103            if (buf.charAt(index) == '0') {
104                buf.setCharAt(index, ' ');
105            }
106        }
107    
108        /**
109         * SyslogLayout's content format is specified by:<p/>
110         * Key: "structured" Value: "false"<p/>
111         * Key: "dateFormat" Value: "MMM dd HH:mm:ss "<p/>
112         * Key: "format" Value: "<LEVEL>TIMESTAMP PROP(HOSTNAME) MESSAGE"<p/>
113         * Key: "formatType" Value: "logfilepatternreceiver" (format uses the keywords supported by LogFilePatternReceiver)
114         * @return Map of content format keys supporting SyslogLayout
115         */
116        @Override
117        public Map<String, String> getContentFormat()
118        {
119            final Map<String, String> result = new HashMap<String, String>();
120            result.put("structured", "false");
121            result.put("formatType", "logfilepatternreceiver");
122            result.put("dateFormat", dateFormat.toPattern());
123            result.put("format", "<LEVEL>TIMESTAMP PROP(HOSTNAME) MESSAGE");
124            return result;
125        }
126    
127        /**
128         * Create a SyslogLayout.
129         * @param facility The Facility is used to try to classify the message.
130         * @param includeNewLine If true a newline will be appended to the result.
131         * @param escapeNL Pattern to use for replacing newlines.
132         * @param charset The character set.
133         * @return A SyslogLayout.
134         */
135        @PluginFactory
136        public static SyslogLayout createLayout(
137                @PluginAttribute(value = "facility", defaultString = "LOCAL0") final Facility facility,
138                @PluginAttribute(value = "newLine", defaultBoolean = false) final boolean includeNewLine,
139                @PluginAttribute("newLineEscape") final String escapeNL,
140                @PluginAttribute(value = "charset", defaultString = "UTF-8") final Charset charset) {
141            return new SyslogLayout(facility, includeNewLine, escapeNL, charset);
142        }
143    }