syslogappender.java

apache的log4j源码

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.log4j.net;

import org.apache.log4j.AppenderSkeleton;
import org.apache.log4j.Layout;
import org.apache.log4j.helpers.SyslogQuietWriter;
import org.apache.log4j.helpers.SyslogWriter;
import org.apache.log4j.spi.LoggingEvent;

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;
import java.net.InetAddress;
import java.net.UnknownHostException;

// Contributors: Yves Bossel <[e-mail]>
//               Christopher Taylor <[e-mail]>

/**
    Use SyslogAppender to send log messages to a remote syslog daemon.

    @author Ceki G&uuml;lc&uuml;
    @author Anders Kristensen
 */
public class SyslogAppender extends AppenderSkeleton {
  // The following constants are extracted from a syslog.h file
  // copyrighted by the Regents of the University of California
  // I hope nobody at Berkley gets offended.

  /** Kernel messages */
  final static public int LOG_KERN     = 0;
  /** Random user-level messages */
  final static public int LOG_USER     = 1<<3;
  /** Mail system */
  final static public int LOG_MAIL     = 2<<3;
  /** System daemons */
  final static public int LOG_DAEMON   = 3<<3;
  /** security/authorization messages */
  final static public int LOG_AUTH     = 4<<3;
  /** messages generated internally by syslogd */
  final static public int LOG_SYSLOG   = 5<<3;

  /** line printer subsystem */
  final static public int LOG_LPR      = 6<<3;
  /** network news subsystem */
  final static public int LOG_NEWS     = 7<<3;
  /** UUCP subsystem */
  final static public int LOG_UUCP     = 8<<3;
  /** clock daemon */
  final static public int LOG_CRON     = 9<<3;
  /** security/authorization  messages (private) */
  final static public int LOG_AUTHPRIV = 10<<3;
  /** ftp daemon */
  final static public int LOG_FTP      = 11<<3;

  // other codes through 15 reserved for system use
  /** reserved for local use */
  final static public int LOG_LOCAL0 = 16<<3;
  /** reserved for local use */
  final static public int LOG_LOCAL1 = 17<<3;
  /** reserved for local use */
  final static public int LOG_LOCAL2 = 18<<3;
  /** reserved for local use */
  final static public int LOG_LOCAL3 = 19<<3;
  /** reserved for local use */
  final static public int LOG_LOCAL4 = 20<<3;
  /** reserved for local use */
  final static public int LOG_LOCAL5 = 21<<3;
  /** reserved for local use */
  final static public int LOG_LOCAL6 = 22<<3;
  /** reserved for local use*/
  final static public int LOG_LOCAL7 = 23<<3;

  protected static final int SYSLOG_HOST_OI = 0;
  protected static final int FACILITY_OI = 1;

  static final String TAB = "    ";

  // Have LOG_USER as default
  int syslogFacility = LOG_USER;
  String facilityStr;
  boolean facilityPrinting = false;

  //SyslogTracerPrintWriter stp;
  SyslogQuietWriter sqw;
  String syslogHost;

    /**
     * If true, the appender will generate the HEADER (timestamp and host name)
     * part of the syslog packet.
     * @since 1.2.15
     */
  private boolean header = false;
    /**
     * Date format used if header = true.
     * @since 1.2.15
     */
  private final SimpleDateFormat dateFormat = new SimpleDateFormat("MMM dd HH:mm:ss ", Locale.ENGLISH);
    /**
     * Host name used to identify messages from this appender.
     * @since 1.2.15
     */
  private String localHostname;

    /**
     * Set to true after the header of the layout has been sent or if it has none.
     */
  private boolean layoutHeaderChecked = false;

  public
  SyslogAppender() {
    this.initSyslogFacilityStr();
  }

  public
  SyslogAppender(Layout layout, int syslogFacility) {
    this.layout = layout;
    this.syslogFacility = syslogFacility;
    this.initSyslogFacilityStr();
  }

  public
  SyslogAppender(Layout layout, String syslogHost, int syslogFacility) {
    this(layout, syslogFacility);
    setSyslogHost(syslogHost);
  }

  /**
     Release any resources held by this SyslogAppender.

     @since 0.8.4
   */
  synchronized
  public
  void close() {
    closed = true;
    if (sqw != null) {
        try {
            if (layoutHeaderChecked && layout != null && layout.getFooter() != null) {
                sendLayoutMessage(layout.getFooter());
            }
            sqw.close();
            sqw = null;
        } catch(java.io.IOException ex) {
            sqw = null;
        }
    }
  }

  private
  void initSyslogFacilityStr() {
    facilityStr = getFacilityString(this.syslogFacility);

    if (facilityStr == null) {
      System.err.println("\"" + syslogFacility +
                  "\" is an unknown syslog facility. Defaulting to \"USER\".");
      this.syslogFacility = LOG_USER;
      facilityStr = "user:";
    } else {
      facilityStr += ":";
    }
  }

  /**
     Returns the specified syslog facility as a lower-case String,
     e.g. "kern", "user", etc.
  */
  public
  static
  String getFacilityString(int syslogFacility) {
    switch(syslogFacility) {
    case LOG_KERN:      return "kern";
    case LOG_USER:      return "user";
    case LOG_MAIL:      return "mail";
    case LOG_DAEMON:    return "daemon";
    case LOG_AUTH:      return "auth";
    case LOG_SYSLOG:    return "syslog";
    case LOG_LPR:       return "lpr";
    case LOG_NEWS:      return "news";
    case LOG_UUCP:      return "uucp";
    case LOG_CRON:      return "cron";
    case LOG_AUTHPRIV:  return "authpriv";
    case LOG_FTP:       return "ftp";
    case LOG_LOCAL0:    return "local0";
    case LOG_LOCAL1:    return "local1";
    case LOG_LOCAL2:    return "local2";
    case LOG_LOCAL3:    return "local3";
    case LOG_LOCAL4:    return "local4";
    case LOG_LOCAL5:    return "local5";
    case LOG_LOCAL6:    return "local6";
    case LOG_LOCAL7:    return "local7";
    default:            return null;
    }
  }

  /**
     Returns the integer value corresponding to the named syslog
     facility, or -1 if it couldn't be recognized.

     @param facilityName one of the strings KERN, USER, MAIL, DAEMON,
            AUTH, SYSLOG, LPR, NEWS, UUCP, CRON, AUTHPRIV, FTP, LOCAL0,
            LOCAL1, LOCAL2, LOCAL3, LOCAL4, LOCAL5, LOCAL6, LOCAL7.
            The matching is case-insensitive.

     @since 1.1
  */
  public
  static
  int getFacility(String facilityName) {
    if(facilityName != null) {
      facilityName = facilityName.trim();
    }
    if("KERN".equalsIgnoreCase(facilityName)) {
      return LOG_KERN;
    } else if("USER".equalsIgnoreCase(facilityName)) {
      return LOG_USER;
    } else if("MAIL".equalsIgnoreCase(facilityName)) {
      return LOG_MAIL;
    } else if("DAEMON".equalsIgnoreCase(facilityName)) {
      return LOG_DAEMON;
    } else if("AUTH".equalsIgnoreCase(facilityName)) {
      return LOG_AUTH;
    } else if("SYSLOG".equalsIgnoreCase(facilityName)) {
      return LOG_SYSLOG;
    } else if("LPR".equalsIgnoreCase(facilityName)) {
      return LOG_LPR;
    } else if("NEWS".equalsIgnoreCase(facilityName)) {
      return LOG_NEWS;
    } else if("UUCP".equalsIgnoreCase(facilityName)) {
      return LOG_UUCP;
    } else if("CRON".equalsIgnoreCase(facilityName)) {
      return LOG_CRON;
    } else if("AUTHPRIV".equalsIgnoreCase(facilityName)) {
      return LOG_AUTHPRIV;
    } else if("FTP".equalsIgnoreCase(facilityName)) {
      return LOG_FTP;
    } else if("LOCAL0".equalsIgnoreCase(facilityName)) {
      return LOG_LOCAL0;
    } else if("LOCAL1".equalsIgnoreCase(facilityName)) {
      return LOG_LOCAL1;
    } else if("LOCAL2".equalsIgnoreCase(facilityName)) {
      return LOG_LOCAL2;
    } else if("LOCAL3".equalsIgnoreCase(facilityName)) {
      return LOG_LOCAL3;
    } else if("LOCAL4".equalsIgnoreCase(facilityName)) {
      return LOG_LOCAL4;
    } else if("LOCAL5".equalsIgnoreCase(facilityName)) {
      return LOG_LOCAL5;