「タスクのカテゴリ」は死にステータスみたいなもんなので②の問題は許容できるだろうが、「イベントID固定」の①はいただけない。

今回は「log4j 1.2を拡張する方法」についてご説明しよう。

package org.apache.log4j.nt;

import org.apache.log4j.AppenderSkeleton;
import org.apache.log4j.Layout;
import org.apache.log4j.TTCCLayout;
import org.apache.log4j.helpers.LogLog;
import org.apache.log4j.spi.LoggingEvent;

/**
 * イベントID、タスクのカテゴリが指定できるようにNTEventLogAppenderを拡張したクラスです。
 * @author J.in.ny
 */
public class NTEventLogAppenderEx extends AppenderSkeleton {

 - 残りを表示 - 


 /** イベントログのハンドル */
  private int _handle = 0;

  /** ソース */
  private String source = null;

  /** リモートサーバー名。nullの場合はローカルコンピュータ名 */
  private String server = null;

  /** イベントID */
  private int eventId = 0;

  /** タスクのカテゴリ */
  private short category = 0;

  /**
   * コンストラクタ
   */
  public NTEventLogAppenderEx() {
    this(null, null, null);
  }

  /**
   * コンストラクタ
   * @param source ソース
   */
  public NTEventLogAppenderEx(String source) {
    this(null, source, null);
  }

  /**
   * コンストラクタ
   * @param server リモートサーバー名
   * @param source ソース
   */
  public NTEventLogAppenderEx(String server, String source) {
    this(server, source, null);
  }

  /**
   * コンストラクタ
   * @param layout レイアウト
   */
  public NTEventLogAppenderEx(Layout layout) {
    this(null, null, layout);
  }

  /**
   * コンストラクタ
   * @param source ソース
   * @param layout レイアウト
   */
  public NTEventLogAppenderEx(String source, Layout layout) {
    this(null, source, layout);
  }

  /**
   * コンストラクタ
   * @param server リモートサーバー名
   * @param source ソース
   * @param layout レイアウト
   */
  public NTEventLogAppenderEx(String server, String source, Layout layout) {
    if (source == null) {
      source = "Log4j";
    }
    if (layout == null) {
      this.layout = new TTCCLayout();
    } else {
      this.layout = layout;
    }

    try {
      _handle = registerEventSource(server, source);
    } catch (Exception e) {
      e.printStackTrace();
      _handle = 0;
    }
  }

  @Override
  public void close() {
    // unregister ...
  }

  @Override
  public void activateOptions() {
    if (source != null) {
      try {
        _handle = registerEventSource(server, source);
      } catch (Exception e) {
        LogLog.error("Could not register event source.", e);
        _handle = 0;
      }
    }
  }

  @Override
  public void append(LoggingEvent event) {

    StringBuffer sbuf = new StringBuffer();

    sbuf.append(layout.format(event));
    if (layout.ignoresThrowable()) {
      String[] s = event.getThrowableStrRep();
      if (s != null) {
        int len = s.length;
        for (int i = 0; i < len; i++) {
          sbuf.append(s[i]);
        }
      }
    }
    // Normalize the log message level into the supported categories
    int nt_category = event.getLevel().toInt();

    // イベントログを出力する
    reportEvent(_handle, sbuf.toString(), nt_category, this.eventId, this.category);
  }

  @Override
  public void finalize() {
    deregisterEventSource(_handle);
    _handle = 0;
  }

  /**
   * The Source option which names the source of the event. The
   * current value of this constant is Source.
   * @param source
   */
  public void setSource(String source) {
    this.source = source.trim();
  }

  /**
   * ソースを取得します。
   * @return ソース
   */
  public String getSource() {
    return source;
  }

  /**
   * イベントIDをセットします。
   * @param eventId セットするイベントID
   */
  public void setEventId(int eventId) {
    this.eventId = eventId;
  }

  /**
   * タスクのカテゴリをセットします。
   * @param category セットするタスクのカテゴリ
   */
  public void setCategory(short category) {
    this.category = category;
  }

  /**
   * The NTEventLogAppender requires a layout. Hence,
   * this method always returns true.
   */
  @Override
  public boolean requiresLayout() {
    return true;
  }

  static {
    String[] archs;
    try {
      archs = new String[] { System.getProperty("os.arch") };
    } catch (SecurityException e) {
      archs = new String[] { "amd64", "ia64", "x86" };
    }
    try {
      boolean loaded = false;
      for (int i = 0; i < archs.length; i++) {
        try {
          System.loadLibrary("NTEventLogAppenderEx." + archs[i]);
          loaded = true;
          break;
        } catch (java.lang.UnsatisfiedLinkError e) {
          loaded = false;
        }
      }
      if (!loaded) {
        System.loadLibrary("NTEventLogAppenderEx");
      }
    } catch (Error err) {
      err.printStackTrace();
    }
  }

  /**
   * ソースを登録し、イベントログのハンドルを取得します。
   * @param server サーバ
   * @param source ソース
   * @return イベントログのハンドル
   */
  native private int registerEventSource(String server, String source);

  /**
   * イベントログを出力します。
   * @param handle イベントログのハンドル
   * @param message メッセージ
   * @param level メッセージレベル
   * @param eventId イベントID
   * @param category タスクのカテゴリ
   */
  native private void reportEvent(int handle, String message, int level, int eventId, short category);

  /**
   * ソースを解除します。
   * @param handle イベントログのハンドル
   */
  native private void deregisterEventSource(int handle);

}

 - 折りたたむ - 

SET JAVA_BIN="C:\Program Files\Java\jdk1.8.0_31\bin"
%JAVA_BIN%\javah -classpath ../lib/log4j-1.2.17.jar;../bin -d ../header org.apache.log4j.nt.NTEventLogAppenderEx
pause

package org.apache.log4j.nt;
#ifndef NtEventLogAppender_h
#define NtEventLogAppender_h

#ifdef __GNUC__
typedef long long __int64;
#endif

#include "org_apache_log4j_Priority.h"
#include "org_apache_log4j_nt_NTEventLogAppenderEx.h"
#include 
#include 

HINSTANCE gModule = 0;

 - 残りを表示 - 

class EventSourceMap {
#if _WIN64
  enum { MAX_SOURCES = 256 };
  HANDLE* sources;
  public:
  EventSourceMap() {
    sources = (HANDLE*) calloc(MAX_SOURCES, sizeof(*sources));
  }

  ~EventSourceMap() {
    free(sources);
  }

  jint createKey(HANDLE handle) {
    if (handle != 0) {
      //
      //   find first available null entry (excluding sources[0])
      //
      for(int i = 1; i < MAX_SOURCES; i++) {
        if (InterlockedCompareExchangePointer(sources + i, handle, 0) == 0) {
          return i;
        }
      }
    }
    return 0;
  }

  HANDLE getHandle(jint key) {
    if (key >= 1 && key < MAX_SOURCES) {
      return sources[key];
    }
    return 0;
  }

  HANDLE releaseHandle(jint key) {
    if (key >= 1 && key < MAX_SOURCES) {
      return InterlockedExchangePointer(sources + key, 0);
    }
    return 0;
  }
#else
  public:
  EventSourceMap() {}

  jint createKey(HANDLE handle) {
    return (jint)handle;
  }

  HANDLE getHandle(jint key) {
    return (HANDLE)key;
  }

  HANDLE releaseHandle(jint key) {
    return (HANDLE)key;
  }
#endif
} gEventSources;

/*
 * Convert log4j Priority to an EventLog category. Each category is
 * backed by a message resource so that proper category names will
 * be displayed in the NT Event Viewer.
 */
WORD getCategory(jint priority) {
  WORD category = 1;
  if (priority >= org_apache_log4j_Priority_DEBUG_INT) {
    category = 2;
    if (priority >= org_apache_log4j_Priority_INFO_INT) {
      category = 3;
      if (priority >= org_apache_log4j_Priority_WARN_INT) {
        category = 4;
        if (priority >= org_apache_log4j_Priority_ERROR_INT) {
          category = 5;
          if (priority >= org_apache_log4j_Priority_FATAL_INT) {
            category = 6;
          }
        }
      }
    }
  }
  return category;
}

/*
 * Convert log4j Priority to an EventLog type. The log4j package
 * supports 8 defined priorites, but the NT EventLog only knows
 * 3 event types of interest to us: ERROR, WARNING, and INFO.
 */
WORD getType(jint priority) {
  WORD type = EVENTLOG_SUCCESS;
  if (priority >= org_apache_log4j_Priority_INFO_INT) {
    type = EVENTLOG_INFORMATION_TYPE;
    if (priority >= org_apache_log4j_Priority_WARN_INT) {
      type = EVENTLOG_WARNING_TYPE;
      if (priority >= org_apache_log4j_Priority_ERROR_INT) {
        type = EVENTLOG_ERROR_TYPE;
      }
    }
  }
  return type;
}

HKEY regGetKey(wchar_t *subkey, DWORD *disposition) {
  HKEY hkey = 0;
  RegCreateKeyExW(HKEY_LOCAL_MACHINE, subkey, 0, NULL,
     REG_OPTION_NON_VOLATILE, KEY_SET_VALUE, NULL,
     &hkey, disposition);
  return hkey;
}

void regSetString(HKEY hkey, wchar_t *name, wchar_t *value) {
  RegSetValueExW(hkey, name, 0, REG_EXPAND_SZ,
      (LPBYTE)value, (wcslen(value) + 1) * sizeof(wchar_t));
}

void regSetDword(HKEY hkey, wchar_t *name, DWORD value) {
  RegSetValueExW(hkey, name, 0, REG_DWORD, (LPBYTE)&value, sizeof(DWORD));
}

/*
 * Add this source with appropriate configuration keys to the registry.
 */
void addRegistryInfo(wchar_t *source) {
  const wchar_t *prefix = L"SYSTEM\\CurrentControlSet\\Services\\EventLog\\Application\\";
  DWORD disposition;
  HKEY hkey = 0;
  wchar_t subkey[256];

  wcscpy(subkey, prefix);
  wcscat(subkey, source);
  hkey = regGetKey(subkey, &disposition);
  if (disposition == REG_CREATED_NEW_KEY) {
    HMODULE hmodule = gModule;
    if (hmodule == NULL) {
      hmodule = GetModuleHandleW(L"NTEventLogAppender.dll");
    }
    if (hmodule != NULL) {
      wchar_t modpath[_MAX_PATH];
      DWORD modlen = GetModuleFileNameW(hmodule, modpath, _MAX_PATH - 1);
      if (modlen > 0) {
        modpath[modlen] = 0;
        regSetString(hkey, L"EventMessageFile", modpath);
        regSetString(hkey, L"CategoryMessageFile", modpath);
      }
    }
    regSetDword(hkey, L"TypesSupported", (DWORD)7);
    regSetDword(hkey, L"CategoryCount", (DWORD)6);
  }
  RegCloseKey(hkey);
  return;
}

/*
 * Class:     org.apache.log4j.nt.NTEventLogAppender
 * Method:    registerEventSource
 * Signature: (Ljava/lang/String;Ljava/lang/String;)I
 */
JNIEXPORT jint JNICALL Java_org_apache_log4j_nt_NTEventLogAppenderEx_registerEventSource(
   JNIEnv *env, jobject java_this, jstring server, jstring source) {

  jchar *nserver = 0;
  jchar *nsource = 0;

  if (server != 0) {
    jsize serverLen = env->GetStringLength(server);
    nserver = (jchar*)malloc((serverLen + 1) * sizeof(jchar));
    env->GetStringRegion(server, 0, serverLen, nserver);
    nserver[serverLen] = 0;
  }
  if (source != 0) {
    jsize sourceLen = env->GetStringLength(source);
    nsource = (jchar*)malloc((sourceLen + 1) * sizeof(jchar));
    env->GetStringRegion(source, 0, sourceLen, nsource);
    nsource[sourceLen] = 0;
  }
  // レジストリは事前に登録すべきなので、動的に登録しない
  // addRegistryInfo((wchar_t*)nsource);
  jint handle = gEventSources.createKey(RegisterEventSourceW((const wchar_t*)nserver, (const wchar_t*)nsource));
  free(nserver);
  free(nsource);
  return handle;
}

/*
 * Class:     org_apache_log4j_nt_NTEventLogAppender
 * Method:    reportEvent
 * Signature: (ILjava/lang/String;I)V
 */
JNIEXPORT void JNICALL Java_org_apache_log4j_nt_NTEventLogAppenderEx_reportEvent(
  JNIEnv *env, jobject java_this, jint jhandle, jstring jstr, jint priority, jint eventId, jshort category) {

  jboolean localHandle = JNI_FALSE;
  HANDLE handle = gEventSources.getHandle(jhandle);
  if (handle == 0) {
    // Client didn't give us a handle so make a local one.
    handle = RegisterEventSourceW(NULL, L"Log4j");
    localHandle = JNI_TRUE;
  }

  // convert Java String to character array
  jsize msgLen = env->GetStringLength(jstr);
  jchar* msg = (jchar*)malloc((msgLen + 1) * sizeof(jchar));
  env->GetStringRegion(jstr, 0, msgLen, msg);
  msg[msgLen] = 0;

  // This is the only message supported by the package. It is backed by
  // a message resource which consists of just '%1' which is replaced
  // by the string we just created.
  const DWORD messageID = (DWORD)eventId;
  ReportEventW(handle, 
               getType(priority),
               (WORD)category,
               messageID,
               NULL, 1, 0, (const wchar_t**)&msg, NULL);

  free((void *)msg);
  if (localHandle == JNI_TRUE) {
    // Created the handle here so free it here too.
    DeregisterEventSource(handle);
  }
  return;
}

/*
 * Class:     org_apache_log4j_nt_NTEventLogAppender
 * Method:    deregisterEventSource
 * Signature: (I)V
 */
JNIEXPORT void JNICALL Java_org_apache_log4j_nt_NTEventLogAppenderEx_deregisterEventSource(
JNIEnv *env,
jobject java_this,
jint handle) {
  DeregisterEventSource(gEventSources.releaseHandle(handle));
}

//
//  Entry point which registers default event source (Log4j)
//     when invoked using regsvr32 tool.
//
//
extern "C" {
  __declspec(dllexport) HRESULT __stdcall DllRegisterServer(void) {
    HRESULT hr = E_FAIL;
    HMODULE hmodule = gModule;
    if (hmodule == NULL) {
      hmodule = GetModuleHandleW(L"NTEventLogAppender.dll");
    }
    if (hmodule != NULL) {
      wchar_t modpath[_MAX_PATH];
      DWORD modlen = GetModuleFileNameW(hmodule, modpath, _MAX_PATH - 1);
      if (modlen > 0) {
        modpath[modlen] = 0;
        const wchar_t key[] = L"SYSTEM\\CurrentControlSet\\Services\\EventLog\\Application\\Log4j";
        DWORD disposition;
        HKEY hkey = 0;

        LONG stat = RegCreateKeyExW(HKEY_LOCAL_MACHINE, key, 0, NULL,
          REG_OPTION_NON_VOLATILE, KEY_SET_VALUE, NULL,
          &hkey, &disposition);
        if (stat == ERROR_SUCCESS) {
          stat = RegSetValueExW(hkey, L"EventMessageFile", 0, REG_EXPAND_SZ,
            (LPBYTE)modpath, (wcslen(modpath) + 1) * sizeof(wchar_t));
          if (stat == ERROR_SUCCESS) {
            stat = RegSetValueExW(hkey, L"CategoryMessageFile", 0, REG_EXPAND_SZ,
              (LPBYTE)modpath, (wcslen(modpath) + 1) * sizeof(wchar_t));
          }
          if (stat == ERROR_SUCCESS) {
            DWORD value = 7;
            stat = RegSetValueExW(hkey, L"TypesSupported", 0, REG_DWORD, (LPBYTE)&value, sizeof(DWORD));
          }
          if (stat == ERROR_SUCCESS) {
            DWORD value = 6;
            stat = RegSetValueExW(hkey, L"CategoryCount", 0, REG_DWORD, (LPBYTE)&value, sizeof(DWORD));
          }
          LONG closeStat = RegCloseKey(hkey);
          if (stat == ERROR_SUCCESS && closeStat == ERROR_SUCCESS) {
            hr = S_OK;
          }
        }
      }
    }
    return hr;
  }


  //
  //  Entry point which unregisters default event source (Log4j)
  //     when invoked using regsvr32 tool with /u option.
  //
  //
  __declspec(dllexport) HRESULT __stdcall DllUnregisterServer(void) {
    LONG stat = RegDeleteKeyW(HKEY_LOCAL_MACHINE,
      L"SYSTEM\\CurrentControlSet\\Services\\EventLog\\Application\\Log4j");
    return (stat == ERROR_SUCCESS || stat == ERROR_FILE_NOT_FOUND) ? S_OK : E_FAIL;
  }

  BOOL APIENTRY DllMain(HMODULE hModule,
                         DWORD  ul_reason_for_call,
                         LPVOID lpReserved
             ) {
    switch (ul_reason_for_call) {
      case DLL_PROCESS_ATTACH:
        gModule = hModule;
        break;
      case DLL_PROCESS_DETACH:
        gModule = 0;
        break;

      case DLL_THREAD_ATTACH:
      case DLL_THREAD_DETACH:
        break;
    }
    return TRUE;
  }
}
#endif

 - 折りたたむ - 

// org.apache.log4j.Priority.classの定義
#define org_apache_log4j_Priority_DEBUG_INT 10000
#define org_apache_log4j_Priority_INFO_INT 20000
#define org_apache_log4j_Priority_WARN_INT 30000
#define org_apache_log4j_Priority_ERROR_INT 40000
#define org_apache_log4j_Priority_FATAL_INT 50000

LanguageNames=(Japanese=0x0411:MSG00411)

;タスクのカテゴリ
MessageIdTypedef=WORD

MessageId = 1
Facility = Application
Language = Japanese
りんご
.

 - 残りを表示 - 

MessageId = 2
Facility = Application
Language = Japanese
みかん
.
MessageId = 3
Facility = Application
Language = Japanese
パイナポー
.
MessageId = 4
Facility = Application
Language = Japanese
いちご
.
MessageId = 5
Facility = Application
Language = Japanese
メロン
.

;メッセージ
MessageIdTypedef=DWORD

MessageId = 1001
Facility = Application
Language = Japanese
%1
.
MessageId = 1002
Facility = Application
Language = Japanese
%1
.
MessageId = 1003
Facility = Application
Language = Japanese
%1
.
MessageId = 1004
Facility = Application
Language = Japanese
%1
.
MessageId = 1005
Facility = Application
Language = Japanese
%1
.
MessageId = 50000
Facility = Application
Language = Japanese
%1
.

 - 折りたたむ - 

    <!-- イベントログ出力のアペンダ sample-commons-logging -->
    <appender name="event" class="org.apache.log4j.nt.NTEventLogAppenderEx">
        <param name="threshold" value="info" />
        <param name="source" value="SampleCommonsLogging" />
        <layout class="org.apache.log4j.PatternLayout">
        <param name="ConversionPattern" value="[%t]%m" />
        </layout>
    </appender>

package jp.j.sample.commons.logging.logger;

import org.apache.log4j.Level;
import org.apache.log4j.Logger;
import org.apache.log4j.nt.NTEventLogAppenderEx;

/**
 * Windows イベントログのアプリケーションにログを出力するためのロガークラスです。
 * @author J.in.ny
 */
public class EventLogger {

 - 残りを表示 - 

  /** ロガー */
  private Logger logger = Logger.getLogger("event");

  /**
   * コンストラクタ
   */
  public EventLogger() {}

  /**
   * アペンダを終了させます。
   * @see java.lang.Object#finalize()
   */
  public void deregister() {
    synchronized (logger) {
      NTEventLogAppenderEx ap = (NTEventLogAppenderEx) logger.getAppender("event");
      ap.finalize();
    }
  }

  /**
   * メッセージをイベントログに出力します。
   * @param l ログレベル
   * @param eventId イベントID
   * @param category タスクのカテゴリ
   * @param message イベントログに出力するメッセージ
   */
  public void write(Level l, int eventId, short category, String message) {

    synchronized (logger) {

      // イベントIDとタスクのカテゴリの設定
      NTEventLogAppenderEx ap = (NTEventLogAppenderEx) logger.getAppender("event");
      ap.setEventId(eventId);
      ap.setCategory(category);

      switch (l.toInt()) {
        case Level.FATAL_INT:
          logger.fatal(message);
          break;
        case Level.ERROR_INT:
          logger.error(message);
          break;
        case Level.WARN_INT:
          logger.warn(message);
          break;
        case Level.INFO_INT:
          logger.info(message);
          break;
        default:
          throw new IllegalArgumentException("ログレベルが不正です。level=" + l.toString());
      }
    }
  }
}

 - 折りたたむ - 

package jp.j.sample.commons.logging;

import org.apache.log4j.Level;
import org.apache.log4j.LogManager;

/**
 * テスト用のクラスです。
 * @author J.in.ny
 */
public class LogTest {

  /**
   * コンストラクタ
   */
  public LogTest() { }

  /**
   * イベントログの出力を試験します。
   * @param args 未使用
   */
  public static void main(String[] args) {
    try {
      Log.event.write(Level.INFO, 1001, (short)1, "情報のイベントログを出力します。");
      Log.event.write(Level.WARN, 1002, (short)2, "警告のイベントログを出力します。");
      Log.event.write(Level.ERROR, 1003, (short)3, "エラーのイベントログを出力します。");
      Log.event.write(Level.FATAL, 1004, (short)4, "致命的エラーのイベントログを出力します。");
      Log.event.write(Level.INFO, 1005, (short)5, "情報のイベントログを出力します。");
      Log.event.write(Level.INFO, 50000, (short)0, "情報のイベントログを出力します。");
    } finally {
      Log.event.deregister();
      LogManager.shutdown();
    }
  }
}

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