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    1   /*
    2    * Licensed to the Apache Software Foundation (ASF) under one or more
    3    * contributor license agreements. See the NOTICE file distributed with
    4    * this work for additional information regarding copyright ownership.
    5    * The ASF licenses this file to You under the Apache license, Version 2.0
    6    * (the "License"); you may not use this file except in compliance with
    7    * the License. You may obtain a copy of the License at
    8    *
    9    *      http://www.apache.org/licenses/LICENSE-2.0
    10   *
    11   * Unless required by applicable law or agreed to in writing, software
    12   * distributed under the License is distributed on an "AS IS" BASIS,
    13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    14   * See the license for the specific language governing permissions and
    15   * limitations under the license.
    16   */
    17  package org.apache.logging.log4j.core.layout;
    18
    19  import java.nio.charset.Charset;
    20  import java.text.SimpleDateFormat;
    21  import java.util.Date;
    22  import java.util.HashMap;
    23  import java.util.Locale;
    24  import java.util.Map;
    25  import java.util.regex.Matcher;
    26  import java.util.regex.Pattern;
    27
    28  import org.apache.logging.log4j.core.Layout;
    29  import org.apache.logging.log4j.core.LogEvent;
    30  import org.apache.logging.log4j.core.config.Node;
    31  import org.apache.logging.log4j.core.config.plugins.Plugin;
    32  import org.apache.logging.log4j.core.config.plugins.PluginAttribute;
    33  import org.apache.logging.log4j.core.config.plugins.PluginFactory;
    34  import org.apache.logging.log4j.core.net.Facility;
    35  import org.apache.logging.log4j.core.net.Priority;
    36  import org.apache.logging.log4j.core.util.NetUtils;
    37  import org.apache.logging.log4j.util.Chars;
    38
    39
    40  /**
    41   * Formats a log event as a BSD Log record.
    42   */
    43  @Plugin(name = "SyslogLayout", category = Node.CATEGORY, elementType = Layout.ELEMENT_TYPE, printObject = true)
    44  public final class SyslogLayout extends AbstractStringLayout {
    45
    46      private static final long serialVersionUID = 1L;
    47
    48      /**
    49       * Match newlines in a platform-independent manner.
    50       */
    51      public static final Pattern NEWLINE_PATTERN = Pattern.compile("\\r?\\n");
    52
    53      private final Facility facility;
    54      private final boolean includeNewLine;
    55      private final String escapeNewLine;
    56
    57      /**
    58       * Date format used if header = true.
    59       */
    60      private final SimpleDateFormat dateFormat = new SimpleDateFormat("MMM dd HH:mm:ss", Locale.ENGLISH);
    61      /**
    62       * Host name used to identify messages from this appender.
    63       */
    64      private final String localHostname = NetUtils.getLocalHostname();
    65
    66      protected SyslogLayout(final Facility facility, final boolean includeNL, final String escapeNL, final Charset charset) {
    67          super(charset);
    68          this.facility = facility;
    69          this.includeNewLine = includeNL;
    70          this.escapeNewLine = escapeNL == null ? null : Matcher.quoteReplacement(escapeNL);
    71      }
    72
    73      /**
    74       * Formats a {@link org.apache.logging.log4j.core.LogEvent} in conformance with the BSD Log record format.
    75       *
    76       * @param event The LogEvent
    77       * @return the event formatted as a String.
    78       */
    79      @Override
    80      public String toSerializable(final LogEvent event) {
    81          final StringBuilder buf = new StringBuilder();
    82
    83          buf.append('<');
    84          buf.append(Priority.getPriority(facility, event.getLevel()));
    85          buf.append('>');
    86          addDate(event.getTimeMillis(), buf);
    87          buf.append(Chars.SPACE);
    88          buf.append(localHostname);
    89          buf.append(Chars.SPACE);
    90
    91          String message = event.getMessage().getFormattedMessage();
    92          if (null != escapeNewLine) {
    93              message = NEWLINE_PATTERN.matcher(message).replaceAll(escapeNewLine);
    94          }
    95          buf.append(message);
    96
    97          if (includeNewLine) {
    98              buf.append('\n');
    99          }
    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 }