NTEventLogAppender xref

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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
    18  package org.apache.log4j.nt;
    19
    20  import org.apache.log4j.AppenderSkeleton;
    21  import org.apache.log4j.Layout;
    22  import org.apache.log4j.TTCCLayout;
    23  import org.apache.log4j.helpers.LogLog;
    24  import org.apache.log4j.spi.LoggingEvent;
    25
    26
    27  /**
    28     Append to the NT event log system.
    29
    30     <p><b>WARNING</b> This appender can only be installed and used on a
    31     Windows system.
    32
    33     <p>Do not forget to place NTEventLogAppender.dll,
    34     NTEventLogAppender.amd64.dll, NTEventLogAppender.ia64.dll
    35     or NTEventLogAppender.x86.dll as appropriate in a
    36     directory that is on the PATH of the Windows system. Otherwise, you
    37     will get a java.lang.UnsatisfiedLinkError.
    38
    39     @author <a href="mailto:cstaylor@pacbell.net">Chris Taylor</a>
    40     @author <a href="mailto:jim_cakalic@na.biomerieux.com">Jim Cakalic</a> */
    41  public class NTEventLogAppender extends AppenderSkeleton {
    42    private int _handle = 0;
    43
    44    private String source = null;
    45    private String server = null;
    46
    47
    48    public NTEventLogAppender() {
    49      this(null, null, null);
    50    }
    51
    52    public NTEventLogAppender(String source) {
    53      this(null, source, null);
    54    }
    55
    56    public NTEventLogAppender(String server, String source) {
    57      this(server, source, null);
    58    }
    59
    60    public NTEventLogAppender(Layout layout) {
    61      this(null, null, layout);
    62    }
    63
    64    public NTEventLogAppender(String source, Layout layout) {
    65      this(null, source, layout);
    66    }
    67
    68    public NTEventLogAppender(String server, String source, Layout layout) {
    69      if (source == null) {
    70        source = "Log4j";
    71      }
    72      if (layout == null) {
    73        this.layout = new TTCCLayout();
    74      } else {
    75        this.layout = layout;
    76      }
    77
    78      try {
    79        _handle = registerEventSource(server, source);
    80      } catch (Exception e) {
    81        e.printStackTrace();
    82        _handle = 0;
    83      }
    84    }
    85
    86    public
    87    void close() {
    88      // unregister ...
    89    }
    90
    91    public
    92    void activateOptions() {
    93      if (source != null) {
    94        try {
    95     _handle = registerEventSource(server, source);
    96        } catch (Exception e) {
    97     LogLog.error("Could not register event source.", e);
    98     _handle = 0;
    99        }
    100     }
    101   }
    102
    103
    104   public void append(LoggingEvent event) {
    105
    106     StringBuffer sbuf = new StringBuffer();
    107
    108     sbuf.append(layout.format(event));
    109     if(layout.ignoresThrowable()) {
    110       String[] s = event.getThrowableStrRep();
    111       if (s != null) {
    112    int len = s.length;
    113    for(int i = 0; i < len; i++) {
    114      sbuf.append(s[i]);
    115    }
    116       }
    117     }
    118     // Normalize the log message level into the supported categories
    119     int nt_category = event.getLevel().toInt();
    120
    121     // Anything above FATAL or below DEBUG is labeled as INFO.
    122     //if (nt_category > FATAL || nt_category < DEBUG) {
    123     //  nt_category = INFO;
    124     //}
    125     reportEvent(_handle, sbuf.toString(), nt_category);
    126   }
    127
    128
    129   public
    130   void finalize() {
    131     deregisterEventSource(_handle);
    132     _handle = 0;
    133   }
    134
    135   /**
    136      The <b>Source</b> option which names the source of the event. The
    137      current value of this constant is <b>Source</b>.
    138    */
    139   public
    140   void setSource(String source) {
    141     this.source = source.trim();
    142   }
    143
    144   public
    145   String getSource() {
    146     return source;
    147   }
    148
    149 /**
    150      The <code>NTEventLogAppender</code> requires a layout. Hence,
    151      this method always returns <code>true</code>. */
    152   public
    153   boolean requiresLayout() {
    154     return true;
    155   }
    156
    157   native private int registerEventSource(String server, String source);
    158   native private void reportEvent(int handle, String message, int level);
    159   native private void deregisterEventSource(int handle);
    160
    161   static {
    162     String[] archs;
    163     try {
    164         archs = new String[] { System.getProperty("os.arch")};
    165     } catch(SecurityException e) {
    166         archs = new String[] { "amd64", "ia64", "x86"};
    167     }
    168     boolean loaded = false;
    169     for(int i = 0; i < archs.length; i++) {
    170         try {
    171             System.loadLibrary("NTEventLogAppender." + archs[i]);
    172             loaded = true;
    173             break;
    174         } catch(java.lang.UnsatisfiedLinkError e) {
    175             loaded = false;
    176         }
    177     }
    178     if (!loaded) {
    179         System.loadLibrary("NTEventLogAppender");
    180     }
    181 }
    182 }