propertyconfigurator.java

log4j的源码

     See {@link #doConfigure(String, LoggerRepository)} for the expected format.
  */
  static
  public
  void configure(Properties properties) {
    new PropertyConfigurator().doConfigure(properties,
					   LogManager.getLoggerRepository());
  }

  /**
     Like {@link #configureAndWatch(String, long)} except that the
     default delay as defined by {@link FileWatchdog#DEFAULT_DELAY} is
     used.

     @param configFilename A file in key=value format.

  */
  static
  public
  void configureAndWatch(String configFilename) {
    configureAndWatch(configFilename, FileWatchdog.DEFAULT_DELAY);
  }


  /**
     Read the configuration file <code>configFilename</code> if it
     exists. Moreover, a thread will be created that will periodically
     check if <code>configFilename</code> has been created or
     modified. The period is determined by the <code>delay</code>
     argument. If a change or file creation is detected, then
     <code>configFilename</code> is read to configure log4j.

      @param configFilename A file in key=value format.
      @param delay The delay in milliseconds to wait between each check.
  */
  static
  public
  void configureAndWatch(String configFilename, long delay) {
    PropertyWatchdog pdog = new PropertyWatchdog(configFilename);
    pdog.setDelay(delay);
    pdog.start();
  }


  /**
     Read configuration options from <code>properties</code>.

     See {@link #doConfigure(String, LoggerRepository)} for the expected format.
  */
  public
  void doConfigure(Properties properties, LoggerRepository hierarchy) {

    String value = properties.getProperty(LogLog.DEBUG_KEY);
    if(value == null) {
      value = properties.getProperty(LogLog.CONFIG_DEBUG_KEY);
      if(value != null)
	LogLog.warn("[log4j.configDebug] is deprecated. Use [log4j.debug] instead.");
    }

    if(value != null) {
      LogLog.setInternalDebugging(OptionConverter.toBoolean(value, true));
    }

    String thresholdStr = OptionConverter.findAndSubst(THRESHOLD_PREFIX,
						       properties);
    if(thresholdStr != null) {
      hierarchy.setThreshold(OptionConverter.toLevel(thresholdStr,
						     (Level) Level.ALL));
      LogLog.debug("Hierarchy threshold set to ["+hierarchy.getThreshold()+"].");
    }

    configureRootCategory(properties, hierarchy);
    configureLoggerFactory(properties);
    parseCatsAndRenderers(properties, hierarchy);

    LogLog.debug("Finished configuring.");
    // We don't want to hold references to appenders preventing their
    // garbage collection.
    registry.clear();
  }

  /**
     Read configuration options from url <code>configURL</code>.
   */
  public
  void doConfigure(java.net.URL configURL, LoggerRepository hierarchy) {
    Properties props = new Properties();
    LogLog.debug("Reading configuration from URL " + configURL);
    try {
      props.load(configURL.openStream());
    }
    catch (java.io.IOException e) {
      LogLog.error("Could not read configuration file from URL [" + configURL
		   + "].", e);
      LogLog.error("Ignoring configuration file [" + configURL +"].");
      return;
    }
    doConfigure(props, hierarchy);
  }


  // --------------------------------------------------------------------------
  // Internal stuff
  // --------------------------------------------------------------------------

  /**
     Check the provided <code>Properties</code> object for a
     {@link org.apache.log4j.spi.LoggerFactory LoggerFactory}
     entry specified by {@link #LOGGER_FACTORY_KEY}.  If such an entry
     exists, an attempt is made to create an instance using the default
     constructor.  This instance is used for subsequent Category creations
     within this configurator.

     @see #parseCatsAndRenderers
   */
  protected void configureLoggerFactory(Properties props) {
    String factoryClassName = OptionConverter.findAndSubst(LOGGER_FACTORY_KEY,
							   props);
    if(factoryClassName != null) {
      LogLog.debug("Setting category factory to ["+factoryClassName+"].");
      loggerFactory = (LoggerFactory)
	          OptionConverter.instantiateByClassName(factoryClassName,
							 LoggerFactory.class,
							 loggerFactory);
      PropertySetter.setProperties(loggerFactory, props, FACTORY_PREFIX + ".");
    }
  }

  /*
  void configureOptionHandler(OptionHandler oh, String prefix,
			      Properties props) {
    String[] options = oh.getOptionStrings();
    if(options == null)
      return;

    String value;
    for(int i = 0; i < options.length; i++) {
      value =  OptionConverter.findAndSubst(prefix + options[i], props);
      LogLog.debug(
         "Option " + options[i] + "=[" + (value == null? "N/A" : value)+"].");
      // Some option handlers assume that null value are not passed to them.
      // So don't remove this check
      if(value != null) {
	oh.setOption(options[i], value);
      }
    }
    oh.activateOptions();
  }
  */


  void configureRootCategory(Properties props, LoggerRepository hierarchy) {
    String effectiveFrefix = ROOT_LOGGER_PREFIX;
    String value = OptionConverter.findAndSubst(ROOT_LOGGER_PREFIX, props);

    if(value == null) {
      value = OptionConverter.findAndSubst(ROOT_CATEGORY_PREFIX, props);
      effectiveFrefix = ROOT_CATEGORY_PREFIX;
    }

    if(value == null)
      LogLog.debug("Could not find root logger information. Is this OK?");
    else {
      Logger root = hierarchy.getRootLogger();
      synchronized(root) {
	parseCategory(props, root, effectiveFrefix, INTERNAL_ROOT_NAME, value);
      }
    }
  }


  /**
     Parse non-root elements, such non-root categories and renderers.
  */
  protected
  void parseCatsAndRenderers(Properties props, LoggerRepository hierarchy) {
    Enumeration enumeration = props.propertyNames();
    while(enumeration.hasMoreElements()) {
      String key = (String) enumeration.nextElement();
      if(key.startsWith(CATEGORY_PREFIX) || key.startsWith(LOGGER_PREFIX)) {
	String loggerName = null;
	if(key.startsWith(CATEGORY_PREFIX)) {
	  loggerName = key.substring(CATEGORY_PREFIX.length());
	} else if(key.startsWith(LOGGER_PREFIX)) {
	  loggerName = key.substring(LOGGER_PREFIX.length());
	}
	String value =  OptionConverter.findAndSubst(key, props);
	Logger logger = hierarchy.getLogger(loggerName, loggerFactory);
	synchronized(logger) {
	  parseCategory(props, logger, key, loggerName, value);
	  parseAdditivityForLogger(props, logger, loggerName);
	}
      } else if(key.startsWith(RENDERER_PREFIX)) {
	String renderedClass = key.substring(RENDERER_PREFIX.length());
	String renderingClass = OptionConverter.findAndSubst(key, props);
	if(hierarchy instanceof RendererSupport) {
	  RendererMap.addRenderer((RendererSupport) hierarchy, renderedClass,
				  renderingClass);
	}
      }
    }
  }

  /**
     Parse the additivity option for a non-root category.
   */
  void parseAdditivityForLogger(Properties props, Logger cat,
				  String loggerName) {
    String value = OptionConverter.findAndSubst(ADDITIVITY_PREFIX + loggerName,
					     props);
    LogLog.debug("Handling "+ADDITIVITY_PREFIX + loggerName+"=["+value+"]");
    // touch additivity only if necessary
    if((value != null) && (!value.equals(""))) {
      boolean additivity = OptionConverter.toBoolean(value, true);
      LogLog.debug("Setting additivity for \""+loggerName+"\" to "+
		   additivity);
      cat.setAdditivity(additivity);
    }
  }

  /**
     This method must work for the root category as well.
   */
  void parseCategory(Properties props, Logger logger, String optionKey,
		     String loggerName, String value) {

    LogLog.debug("Parsing for [" +loggerName +"] with value=[" + value+"].");
    // We must skip over ',' but not white space
    StringTokenizer st = new StringTokenizer(value, ",");

    // If value is not in the form ", appender.." or "", then we should set
    // the level of the loggeregory.

    if(!(value.startsWith(",") || value.equals(""))) {

      // just to be on the safe side...
      if(!st.hasMoreTokens())
	return;

      String levelStr = st.nextToken();
      LogLog.debug("Level token is [" + levelStr + "].");

      // If the level value is inherited, set category level value to
      // null. We also check that the user has not specified inherited for the
      // root category.
      if(INHERITED.equalsIgnoreCase(levelStr) || 
 	                                  NULL.equalsIgnoreCase(levelStr)) {
	if(loggerName.equals(INTERNAL_ROOT_NAME)) {
	  LogLog.warn("The root logger cannot be set to null.");
	} else {
	  logger.setLevel(null);
	}
      } else {
	logger.setLevel(OptionConverter.toLevel(levelStr, (Level) Level.DEBUG));
      }
      LogLog.debug("Category " + loggerName + " set to " + logger.getLevel());
    }

    // Begin by removing all existing appenders.
    logger.removeAllAppenders();

    Appender appender;
    String appenderName;
    while(st.hasMoreTokens()) {
      appenderName = st.nextToken().trim();
      if(appenderName == null || appenderName.equals(","))
	continue;
      LogLog.debug("Parsing appender named \"" + appenderName +"\".");
      appender = parseAppender(props, appenderName);
      if(appender != null) {
	logger.addAppender(appender);
      }
    }
  }

  Appender parseAppender(Properties props, String appenderName) {
    Appender appender = registryGet(appenderName);
    if((appender != null)) {
      LogLog.debug("Appender \"" + appenderName + "\" was already parsed.");
      return appender;
    }
    // Appender was not previously initialized.
    String prefix = APPENDER_PREFIX + appenderName;
    String layoutPrefix = prefix + ".layout";

    appender = (Appender) OptionConverter.instantiateByKey(props, prefix,
					      org.apache.log4j.Appender.class,
					      null);
    if(appender == null) {
      LogLog.error(
              "Could not instantiate appender named \"" + appenderName+"\".");
      return null;
    }
    appender.setName(appenderName);

    if(appender instanceof OptionHandler) {
      if(appender.requiresLayout()) {
	Layout layout = (Layout) OptionConverter.instantiateByKey(props,
								  layoutPrefix,
								  Layout.class,
								  null);
	if(layout != null) {
	  appender.setLayout(layout);
	  LogLog.debug("Parsing layout options for \"" + appenderName +"\".");
	  //configureOptionHandler(layout, layoutPrefix + ".", props);
          PropertySetter.setProperties(layout, props, layoutPrefix + ".");
	  LogLog.debug("End of parsing for \"" + appenderName +"\".");
	}
      }
      //configureOptionHandler((OptionHandler) appender, prefix + ".", props);
      PropertySetter.setProperties(appender, props, prefix + ".");
      LogLog.debug("Parsed \"" + appenderName +"\" options.");
    }
    registryPut(appender);
    return appender;
  }


  void  registryPut(Appender appender) {
    registry.put(appender.getName(), appender);
  }

  Appender registryGet(String name) {
    return (Appender) registry.get(name);
  }
}

class PropertyWatchdog extends FileWatchdog {

  PropertyWatchdog(String filename) {
    super(filename);
  }

  /**
     Call {@link PropertyConfigurator#configure(String)} with the
     <code>filename</code> to reconfigure log4j. */
  public
  void doOnChange() {
    new PropertyConfigurator().doConfigure(filename,
					   LogManager.getLoggerRepository());
  }
}