logger.java

gcc的组建

    if (isLoggable(Level.FINER))
      logp(Level.FINER, sourceClass, sourceMethod, "RETURN");
  }

   
  public synchronized void exiting(String sourceClass,
				   String sourceMethod,
				   Object result)
  {
    if (isLoggable(Level.FINER))
      logp(Level.FINER, sourceClass, sourceMethod, "RETURN {0}", result);
  }

 
  public synchronized void throwing(String sourceClass,
				    String sourceMethod,
				    Throwable thrown)
  {
    if (isLoggable(Level.FINER))
      logp(Level.FINER, sourceClass, sourceMethod, "THROW", thrown);
  }


  /**
   * Logs a message with severity level SEVERE, indicating a serious
   * failure that prevents normal program execution.  Messages at this
   * level should be understandable to an inexperienced, non-technical
   * end user.  Ideally, they explain in simple words what actions the
   * user can take in order to resolve the problem.
   *
   * @see Level#SEVERE
   *
   * @param message the message text, also used as look-up key if the
   *                logger is localizing messages with a resource
   *                bundle.  While it is possible to pass
   *                <code>null</code>, this is not recommended, since
   *                a logging message without text is unlikely to be
   *                helpful.
   */
  public synchronized void severe(String message)
  {
    if (isLoggable(Level.SEVERE))
      log(Level.SEVERE, message);
  }


  /**
   * Logs a message with severity level WARNING, indicating a
   * potential problem that does not prevent normal program execution.
   * Messages at this level should be understandable to an
   * inexperienced, non-technical end user.  Ideally, they explain in
   * simple words what actions the user can take in order to resolve
   * the problem.
   *
   * @see Level#WARNING
   *
   * @param message the message text, also used as look-up key if the
   *                logger is localizing messages with a resource
   *                bundle.  While it is possible to pass
   *                <code>null</code>, this is not recommended, since
   *                a logging message without text is unlikely to be
   *                helpful.
   */
  public synchronized void warning(String message)
  {
    if (isLoggable(Level.WARNING))
      log(Level.WARNING, message);
  }


  /**
   * Logs a message with severity level INFO.  {@link Level#INFO} is
   * intended for purely informational messages that do not indicate
   * error or warning situations. In the default logging
   * configuration, INFO messages will be written to the system
   * console.  For this reason, the INFO level should be used only for
   * messages that are important to end users and system
   * administrators.  Messages at this level should be understandable
   * to an inexperienced, non-technical user.
   *
   * @param message the message text, also used as look-up key if the
   *                logger is localizing messages with a resource
   *                bundle.  While it is possible to pass
   *                <code>null</code>, this is not recommended, since
   *                a logging message without text is unlikely to be
   *                helpful.
   */
  public synchronized void info(String message)
  {
    if (isLoggable(Level.INFO))
      log(Level.INFO, message);
  }


  /**
   * Logs a message with severity level CONFIG.  {@link Level#CONFIG} is
   * intended for static configuration messages, for example about the
   * windowing environment, the operating system version, etc.
   *
   * @param message the message text, also used as look-up key if the
   *     logger is localizing messages with a resource bundle.  While
   *     it is possible to pass <code>null</code>, this is not
   *     recommended, since a logging message without text is unlikely
   *     to be helpful.
   */
  public synchronized void config(String message)
  {
    if (isLoggable(Level.CONFIG))
      log(Level.CONFIG, message);
  }


  /**
   * Logs a message with severity level FINE.  {@link Level#FINE} is
   * intended for messages that are relevant for developers using
   * the component generating log messages. Examples include minor,
   * recoverable failures, or possible inefficiencies.
   *
   * @param message the message text, also used as look-up key if the
   *                logger is localizing messages with a resource
   *                bundle.  While it is possible to pass
   *                <code>null</code>, this is not recommended, since
   *                a logging message without text is unlikely to be
   *                helpful.
   */
  public synchronized void fine(String message)
  {
    if (isLoggable(Level.FINE))
      log(Level.FINE, message);
  }


  /**
   * Logs a message with severity level FINER.  {@link Level#FINER} is
   * intended for rather detailed tracing, for example entering a
   * method, returning from a method, or throwing an exception.
   *
   * @param message the message text, also used as look-up key if the
   *                logger is localizing messages with a resource
   *                bundle.  While it is possible to pass
   *                <code>null</code>, this is not recommended, since
   *                a logging message without text is unlikely to be
   *                helpful.
   */
  public synchronized void finer(String message)
  {
    if (isLoggable(Level.FINER))
      log(Level.FINER, message);
  }


  /**
   * Logs a message with severity level FINEST.  {@link Level#FINEST}
   * is intended for highly detailed tracing, for example reaching a
   * certain point inside the body of a method.
   *
   * @param message the message text, also used as look-up key if the
   *                logger is localizing messages with a resource
   *                bundle.  While it is possible to pass
   *                <code>null</code>, this is not recommended, since
   *                a logging message without text is unlikely to be
   *                helpful.
   */
  public synchronized void finest(String message)
  {
    if (isLoggable(Level.FINEST))
      log(Level.FINEST, message);
  }


  /**
   * Adds a handler to the set of handlers that get notified
   * when a log record is to be published.
   *
   * @param handler the handler to be added.
   *
   * @throws NullPointerException if <code>handler</code>
   *     is <code>null</code>.
   *
   * @throws SecurityException if this logger is not anonymous, a
   *     security manager exists, and the caller is not granted
   *     the permission to control the logging infrastructure by
   *     having LoggingPermission("control").  Untrusted code can
   *     obtain an anonymous logger through the static factory method
   *     {@link #getAnonymousLogger(java.lang.String) getAnonymousLogger}.
   */
  public synchronized void addHandler(Handler handler)
    throws SecurityException
  {
    /* Throw a new NullPointerException if handler is null. */
    handler.getClass();

    /* An application is allowed to control an anonymous logger
     * without having the permission to control the logging
     * infrastructure.
     */
    if (!anonymous)
      LogManager.getLogManager().checkAccess();

    if (!handlerList.contains(handler))
    {
      handlerList.add(handler);
      handlers = getHandlers();
    }
  }


  /**
   * Removes a handler from the set of handlers that get notified
   * when a log record is to be published.
   *
   * @param handler the handler to be removed.
   *
   * @throws SecurityException if this logger is not anonymous, a
   *     security manager exists, and the caller is not granted the
   *     permission to control the logging infrastructure by having
   *     LoggingPermission("control").  Untrusted code can obtain an
   *     anonymous logger through the static factory method {@link
   *     #getAnonymousLogger(java.lang.String) getAnonymousLogger}.
   *
   * @throws NullPointerException if <code>handler</code>
   *     is <code>null</code>.
   */
  public synchronized void removeHandler(Handler handler)
    throws SecurityException
  {
    /* An application is allowed to control an anonymous logger
     * without having the permission to control the logging
     * infrastructure.
     */
    if (!anonymous)
      LogManager.getLogManager().checkAccess();

    /* Throw a new NullPointerException if handler is null. */
    handler.getClass();

    handlerList.remove(handler);
    handlers = getHandlers();
  }


  /**
   * Returns the handlers currently registered for this Logger.
   * When a log record has been deemed as being loggable,
   * it will be passed to all registered handlers for
   * publication.  In addition, if the logger uses parent handlers
   * (see {@link #getUseParentHandlers() getUseParentHandlers}
   * and {@link #setUseParentHandlers(boolean) setUseParentHandlers},
   * the log record will be passed to the parent's handlers.
   */
  public synchronized Handler[] getHandlers()
  {
    /* We cannot return our internal handlers array
     * because we do not have any guarantee that the
     * caller would not change the array entries.
     */
    return (Handler[]) handlerList.toArray(new Handler[handlerList.size()]);
  }


  /**
   * Returns whether or not this Logger forwards log records to
   * handlers registered for its parent loggers.
   *
   * @return <code>false</code> if this Logger sends log records
   *         merely to Handlers registered with itself;
   *         <code>true</code> if this Logger sends log records
   *         not only to Handlers registered with itself, but also
   *         to those Handlers registered with parent loggers.
   */
  public synchronized boolean getUseParentHandlers()
  {
    return useParentHandlers;
  }


  /**
   * Sets whether or not this Logger forwards log records to
   * handlers registered for its parent loggers.
   *
   * @param useParentHandlers <code>false</code> to let this
   *         Logger send log records merely to Handlers registered
   *         with itself; <code>true</code> to let this Logger
   *         send log records not only to Handlers registered
   *         with itself, but also to those Handlers registered with
   *         parent loggers.
   *
   * @throws SecurityException if this logger is not anonymous, a
   *     security manager exists, and the caller is not granted
   *     the permission to control the logging infrastructure by
   *     having LoggingPermission("control").  Untrusted code can
   *     obtain an anonymous logger through the static factory method
   *     {@link #getAnonymousLogger(java.lang.String) getAnonymousLogger}.
   *
   */
  public synchronized void setUseParentHandlers(boolean useParentHandlers)
  {
    /* An application is allowed to control an anonymous logger
     * without having the permission to control the logging
     * infrastructure.
     */
    if (!anonymous)
      LogManager.getLogManager().checkAccess();

    this.useParentHandlers = useParentHandlers;
  }


  /**
   * Returns the parent of this logger.  By default, the parent is
   * assigned by the LogManager by inspecting the logger's name.
   *
   * @return the parent of this logger (as detemined by the LogManager
   *     by inspecting logger names), the root logger if no other
   *     logger has a name which is a prefix of this logger's name, or
   *     <code>null</code> for the root logger.
   */
  public synchronized Logger getParent()
  {
    return parent;
  }


  /**
   * Sets the parent of this logger.  Usually, applications do not
   * call this method directly.  Instead, the LogManager will ensure
   * that the tree of loggers reflects the hierarchical logger
   * namespace.  Basically, this method should not be public at all,
   * but the GNU implementation follows the API specification.
   *
   * @throws NullPointerException if <code>parent</code> is
   *     <code>null</code>.
   *
   * @throws SecurityException if this logger is not anonymous, a
   *     security manager exists, and the caller is not granted
   *     the permission to control the logging infrastructure by
   *     having LoggingPermission("control").  Untrusted code can
   *     obtain an anonymous logger through the static factory method
   *     {@link #getAnonymousLogger(java.lang.String) getAnonymousLogger}.
   */
  public synchronized void setParent(Logger parent)
  {
    LogManager lm;

    /* Throw a new NullPointerException if parent is null. */
    parent.getClass();

    lm = LogManager.getLogManager();

    if (this == lm.rootLogger)
        throw new IllegalArgumentException(
          "only the root logger can have a null parent");

    /* An application is allowed to control an anonymous logger
     * without having the permission to control the logging
     * infrastructure.
     */
    if (!anonymous)
      LogManager.getLogManager().checkAccess();

    this.parent = parent;
  }
  
  /**
   * Gets the StackTraceElement of the first class that is not this class.
   * That should be the initial caller of a logging method.
   * @return caller of the initial logging method or null if unknown.
   */
  private StackTraceElement getCallerStackFrame()
  {
    Throwable t = new Throwable();
    StackTraceElement[] stackTrace = t.getStackTrace();
    int index = 0;

    // skip to stackentries until this class
    while(index < stackTrace.length
	  && !stackTrace[index].getClassName().equals(getClass().getName()))
      index++;

    // skip the stackentries of this class
    while(index < stackTrace.length
	  && stackTrace[index].getClassName().equals(getClass().getName()))
      index++;

    return index < stackTrace.length ? stackTrace[index] : null;
  }
  
  /**
   * Reset and close handlers attached to this logger. This function is package
   * private because it must only be avaiable to the LogManager.
   */
  void resetLogger()
  {
    for (int i = 0; i < handlers.length; i++)
      {
        handlers[i].close();
        handlerList.remove(handlers[i]);
      }
    handlers = getHandlers();
  }
}