org.apache.log4j.helpers.OptionConverter#findAndSubst ( )源码实例Demo

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);
     }
   }
 }
 

private void configureRoot(Properties props) {
    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) {
        LOGGER.debug("Could not find root logger information. Is this OK?");
    } else {
        LoggerConfig root = getRootLogger();
        parseLogger(props, root, effectiveFrefix, INTERNAL_ROOT_NAME, value);
    }
}
 

public Appender parseAppender(Properties props, String appenderName) {
    Appender appender = registry.get(appenderName);
    if ((appender != null)) {
        LOGGER.debug("Appender \"" + appenderName + "\" was already parsed.");
        return appender;
    }
    // Appender was not previously initialized.
    final String prefix = APPENDER_PREFIX + appenderName;
    final String layoutPrefix = prefix + ".layout";
    final String filterPrefix = APPENDER_PREFIX + appenderName + ".filter.";
    String className = OptionConverter.findAndSubst(prefix, props);
    appender = manager.parseAppender(appenderName, className, prefix, layoutPrefix, filterPrefix, props, this);
    if (appender == null) {
        appender = buildAppender(appenderName, className, prefix, layoutPrefix, filterPrefix, props);
    } else {
        registry.put(appenderName, appender);
        if (appender instanceof AppenderWrapper) {
            addAppender(((AppenderWrapper) appender).getAppender());
        } else {
            addAppender(new AppenderAdapter(appender).getAdapter());
        }
    }
    return appender;
}
 

/**
    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("log4j.configDebug");
     if(value != null)
LogLog.warn("[log4j.configDebug] is deprecated. Use [log4j.debug] instead.");
   }

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

     //
     //   if log4j.reset=true then
     //        reset hierarchy
   String reset = properties.getProperty(RESET_KEY);
   if (reset != null && OptionConverter.toBoolean(reset, false)) {
         hierarchy.resetConfiguration();
   }

   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();
 }
 

/**
   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 + ".");
  }
}
 

/**
    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);
  }
}
 

/**
    Set the properites for the object that match the
    <code>prefix</code> passed as parameter.

    
  */
 public
 void setProperties(Properties properties, String prefix) {
   int len = prefix.length();
   
   for (Enumeration e = properties.propertyNames(); e.hasMoreElements(); ) {
     String key = (String) e.nextElement();
     
     // handle only properties that start with the desired frefix.
     if (key.startsWith(prefix)) {


// ignore key if it contains dots after the prefix
       if (key.indexOf('.', len + 1) > 0) {
  //System.err.println("----------Ignoring---["+key
  //	     +"], prefix=["+prefix+"].");
  continue;
}
       
String value = OptionConverter.findAndSubst(key, properties);
       key = key.substring(len);
       if ("layout".equals(key) && obj instanceof Appender) {
         continue;
       }        
       setProperty(key, value);
     }
   }
   activate();
 }
 

/**
 * Parse the additivity option for a non-root category.
 */
private boolean getAdditivityForLogger(Properties props, String loggerName) {
    boolean additivity = true;
    String key = ADDITIVITY_PREFIX + loggerName;
    String value = OptionConverter.findAndSubst(key, props);
    LOGGER.debug("Handling {}=[{}]", key, value);
    // touch additivity only if necessary
    if ((value != null) && (!value.equals(""))) {
        additivity = OptionConverter.toBoolean(value, true);
    }
    return additivity;
}
 

private Appender buildAppender(final String appenderName, final String className, final String prefix,
        final String layoutPrefix, final String filterPrefix, final Properties props) {
    Appender appender = newInstanceOf(className, "Appender");
    if (appender == null) {
        return null;
    }
    appender.setName(appenderName);
    appender.setLayout(parseLayout(layoutPrefix, appenderName, props));
    final String errorHandlerPrefix = prefix + ".errorhandler";
    String errorHandlerClass = OptionConverter.findAndSubst(errorHandlerPrefix, props);
    if (errorHandlerClass != null) {
        ErrorHandler eh = parseErrorHandler(props, errorHandlerPrefix, errorHandlerClass, appender);
        if (eh != null) {
            appender.setErrorHandler(eh);
        }
    }
    parseAppenderFilters(props, filterPrefix, appenderName);
    String[] keys = new String[] {
            layoutPrefix,
    };
    addProperties(appender, keys, props, prefix);
    if (appender instanceof AppenderWrapper) {
        addAppender(((AppenderWrapper) appender).getAppender());
    } else {
        addAppender(new AppenderAdapter(appender).getAdapter());
    }
    registry.put(appenderName, appender);
    return appender;
}
 

public Layout parseLayout(String layoutPrefix, String appenderName, Properties props) {
    String layoutClass = OptionConverter.findAndSubst(layoutPrefix, props);
    if (layoutClass == null) {
        return null;
    }
    Layout layout = manager.parseLayout(layoutClass, layoutPrefix, props, this);
    if (layout == null) {
        layout = buildLayout(layoutPrefix, layoutClass, appenderName, props);
    }
    return layout;
}
 

public Filter parseAppenderFilters(Properties props, String filterPrefix, String appenderName) {
    // extract filters and filter options from props into a hashtable mapping
    // the property name defining the filter class to a list of pre-parsed
    // name-value pairs associated to that filter
    int fIdx = filterPrefix.length();
    SortedMap<String, List<NameValue>> filters = new TreeMap<>();
    Enumeration e = props.keys();
    String name = "";
    while (e.hasMoreElements()) {
        String key = (String) e.nextElement();
        if (key.startsWith(filterPrefix)) {
            int dotIdx = key.indexOf('.', fIdx);
            String filterKey = key;
            if (dotIdx != -1) {
                filterKey = key.substring(0, dotIdx);
                name = key.substring(dotIdx + 1);
            }
            List<NameValue> filterOpts = filters.computeIfAbsent(filterKey, k -> new ArrayList<>());
            if (dotIdx != -1) {
                String value = OptionConverter.findAndSubst(key, props);
                filterOpts.add(new NameValue(name, value));
            }
        }
    }

    Filter head = null;
    Filter next = null;
    for (Map.Entry<String, List<NameValue>> entry : filters.entrySet()) {
        String clazz = props.getProperty(entry.getKey());
        Filter filter = null;
        if (clazz != null) {
            filter = manager.parseFilter(clazz, filterPrefix, props, this);
            if (filter == null) {
                LOGGER.debug("Filter key: [{}] class: [{}] props: {}", entry.getKey(), clazz, entry.getValue());
                filter = buildFilter(clazz, appenderName, entry.getValue());
            }
        }
        if (filter != null) {
            if (head != null) {
                head = filter;
                next = filter;
            } else {
                next.setNext(filter);
                next = filter;
            }
        }
    }
    return head;
}