    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.Layout;
    029    import org.apache.logging.log4j.core.LogEvent;
    030    import org.apache.logging.log4j.core.config.Node;
    031    import org.apache.logging.log4j.core.config.plugins.Plugin;
    032    import org.apache.logging.log4j.core.config.plugins.PluginAttribute;
    033    import org.apache.logging.log4j.core.config.plugins.PluginFactory;
    034    import org.apache.logging.log4j.core.net.Facility;
    035    import org.apache.logging.log4j.core.net.Priority;
    036    import org.apache.logging.log4j.core.util.NetUtils;
    037    import org.apache.logging.log4j.util.Chars;
    038
    039
    040    /**
    041     * Formats a log event as a BSD Log record.
    042     */
    043    @Plugin(name = "SyslogLayout", category = Node.CATEGORY, elementType = Layout.ELEMENT_TYPE, printObject = true)
    044    public final class SyslogLayout extends AbstractStringLayout {
    045
    046        private static final long serialVersionUID = 1L;
    047
    048        /**
    049         * Match newlines in a platform-independent manner.
    050         */
    051        public static final Pattern NEWLINE_PATTERN = Pattern.compile("\\r?\\n");
    052
    053        private final Facility facility;
    054        private final boolean includeNewLine;
    055        private final String escapeNewLine;
    056
    057        /**
    058         * Date format used if header = true.
    059         */
    060        private final SimpleDateFormat dateFormat = new SimpleDateFormat("MMM dd HH:mm:ss", Locale.ENGLISH);
    061        /**
    062         * Host name used to identify messages from this appender.
    063         */
    064        private final String localHostname = NetUtils.getLocalHostname();
    065
    066        protected SyslogLayout(final Facility facility, final boolean includeNL, final String escapeNL, final Charset charset) {
    067            super(charset);
    068            this.facility = facility;
    069            this.includeNewLine = includeNL;
    070            this.escapeNewLine = escapeNL == null ? null : Matcher.quoteReplacement(escapeNL);
    071        }
    072
    073        /**
    074         * Formats a {@link org.apache.logging.log4j.core.LogEvent} in conformance with the BSD Log record format.
    075         *
    076         * @param event The LogEvent
    077         * @return the event formatted as a String.
    078         */
    079        @Override
    080        public String toSerializable(final LogEvent event) {
    081            final StringBuilder buf = new StringBuilder();
    082
    083            buf.append('<');
    084            buf.append(Priority.getPriority(facility, event.getLevel()));
    085            buf.append('>');
    086            addDate(event.getTimeMillis(), buf);
    087            buf.append(Chars.SPACE);
    088            buf.append(localHostname);
    089            buf.append(Chars.SPACE);
    090
    091            String message = event.getMessage().getFormattedMessage();
    092            if (null != escapeNewLine) {
    093                message = NEWLINE_PATTERN.matcher(message).replaceAll(escapeNewLine);
    094            }
    095            buf.append(message);
    096
    097            if (includeNewLine) {
    098                buf.append('\n');
    099            }
    100            return buf.toString();
    101        }
    102
    103        private synchronized void addDate(final long timestamp, final StringBuilder buf) {
    104            final int index = buf.length() + 4;
    105            buf.append(dateFormat.format(new Date(timestamp)));
    106            //  RFC 3164 says leading space, not leading zero on days 1-9
    107            if (buf.charAt(index) == '0') {
    108                buf.setCharAt(index, Chars.SPACE);
    109            }
    110        }
    111
    112        /**
    113         * Gets this SyslogLayout's content format. Specified by:
    114         * <ul>
    115         * <li>Key: "structured" Value: "false"</li>
    116         * <li>Key: "dateFormat" Value: "MMM dd HH:mm:ss"</li>
    117         * <li>Key: "format" Value: "&lt;LEVEL&gt;TIMESTAMP PROP(HOSTNAME) MESSAGE"</li>
    118         * <li>Key: "formatType" Value: "logfilepatternreceiver" (format uses the keywords supported by
    119         * LogFilePatternReceiver)</li>
    120         * </ul>
    121         *
    122         * @return Map of content format keys supporting SyslogLayout
    123         */
    124        @Override
    125        public Map<String, String> getContentFormat() {
    126            final Map<String, String> result = new HashMap<String, String>();
    127            result.put("structured", "false");
    128            result.put("formatType", "logfilepatternreceiver");
    129            result.put("dateFormat", dateFormat.toPattern());
    130            result.put("format", "<LEVEL>TIMESTAMP PROP(HOSTNAME) MESSAGE");
    131            return result;
    132        }
    133
    134        /**
    135         * Create a SyslogLayout.
    136         * @param facility The Facility is used to try to classify the message.
    137         * @param includeNewLine If true a newline will be appended to the result.
    138         * @param escapeNL Pattern to use for replacing newlines.
    139         * @param charset The character set.
    140         * @return A SyslogLayout.
    141         */
    142        @PluginFactory
    143        public static SyslogLayout createLayout(
    144                @PluginAttribute(value = "facility", defaultString = "LOCAL0") final Facility facility,
    145                @PluginAttribute(value = "newLine", defaultBoolean = false) final boolean includeNewLine,
    146                @PluginAttribute("newLineEscape") final String escapeNL,
    147                @PluginAttribute(value = "charset", defaultString = "UTF-8") final Charset charset) {
    148            return new SyslogLayout(facility, includeNewLine, escapeNL, charset);
    149        }
    150    }