FileDocCategorySizeDatePackage
LogManager.javaAPI DocApache log4j 1.2.158259Sat Aug 25 00:09:42 BST 2007org.apache.log4j

LogManager

public class LogManager extends Object
Use the LogManager class to retreive {@link Logger} instances or to operate on the current {@link LoggerRepository}. When the LogManager class is loaded into memory the default initalzation procedure is inititated. The default intialization procedure is described in the short log4j manual.
author
Ceki Gülcü

Fields Summary
public static final String
DEFAULT_CONFIGURATION_FILE
static final String
DEFAULT_XML_CONFIGURATION_FILE
public static final String
DEFAULT_CONFIGURATION_KEY
public static final String
CONFIGURATOR_CLASS_KEY
public static final String
DEFAULT_INIT_OVERRIDE_KEY
private static Object
guard
private static RepositorySelector
repositorySelector
Constructors Summary
Methods Summary
public static org.apache.log4j.Loggerexists(java.lang.String name)

    return getLoggerRepository().exists(name);
public static java.util.EnumerationgetCurrentLoggers()

    return getLoggerRepository().getCurrentLoggers();
public static org.apache.log4j.LoggergetLogger(java.lang.String name)
Retrieve the appropriate {@link Logger} instance.

     // Delegate the actual manufacturing of the logger to the logger repository.
    return getLoggerRepository().getLogger(name);
public static org.apache.log4j.LoggergetLogger(java.lang.Class clazz)
Retrieve the appropriate {@link Logger} instance.

     // Delegate the actual manufacturing of the logger to the logger repository.
    return getLoggerRepository().getLogger(clazz.getName());
public static org.apache.log4j.LoggergetLogger(java.lang.String name, org.apache.log4j.spi.LoggerFactory factory)
Retrieve the appropriate {@link Logger} instance.

     // Delegate the actual manufacturing of the logger to the logger repository.
    return getLoggerRepository().getLogger(name, factory);
public static org.apache.log4j.spi.LoggerRepositorygetLoggerRepository()

    if (repositorySelector == null) {
        repositorySelector = new DefaultRepositorySelector(new NOPLoggerRepository());
        guard = null;
        LogLog.error("LogMananger.repositorySelector was null likely due to error in class reloading, using NOPLoggerRepository.");
    }
    return repositorySelector.getLoggerRepository();
public static org.apache.log4j.LoggergetRootLogger()
Retrieve the appropriate root logger.

     // Delegate the actual manufacturing of the logger to the logger repository.
    return getLoggerRepository().getRootLogger();
public static voidresetConfiguration()

    getLoggerRepository().resetConfiguration();
public static voidsetRepositorySelector(org.apache.log4j.spi.RepositorySelector selector, java.lang.Object guard)
Sets LoggerFactory but only if the correct guard is passed as parameter.

Initally the guard is null. If the guard is null, then invoking this method sets the logger factory and the guard. Following invocations will throw a {@link IllegalArgumentException}, unless the previously set guard is passed as the second parameter.

This allows a high-level component to set the {@link RepositorySelector} used by the LogManager.

For example, when tomcat starts it will be able to install its own repository selector. However, if and when Tomcat is embedded within JBoss, then JBoss will install its own repository selector and Tomcat will use the repository selector set by its container, JBoss.


   
    // By default we use a DefaultRepositorySelector which always returns 'h'.
    Hierarchy h = new Hierarchy(new RootLogger((Level) Level.DEBUG));
    repositorySelector = new DefaultRepositorySelector(h);

    /** Search for the properties file log4j.properties in the CLASSPATH.  */
    String override =OptionConverter.getSystemProperty(DEFAULT_INIT_OVERRIDE_KEY,
						       null);

    // if there is no default init override, then get the resource
    // specified by the user or the default config file.
    if(override == null || "false".equalsIgnoreCase(override)) {

      String configurationOptionStr = OptionConverter.getSystemProperty(
							  DEFAULT_CONFIGURATION_KEY, 
							  null);

      String configuratorClassName = OptionConverter.getSystemProperty(
                                                   CONFIGURATOR_CLASS_KEY, 
						   null);

      URL url = null;

      // if the user has not specified the log4j.configuration
      // property, we search first for the file "log4j.xml" and then
      // "log4j.properties"
      if(configurationOptionStr == null) {	
	url = Loader.getResource(DEFAULT_XML_CONFIGURATION_FILE);
	if(url == null) {
	  url = Loader.getResource(DEFAULT_CONFIGURATION_FILE);
	}
      } else {
	try {
	  url = new URL(configurationOptionStr);
	} catch (MalformedURLException ex) {
	  // so, resource is not a URL:
	  // attempt to get the resource from the class path
	  url = Loader.getResource(configurationOptionStr); 
	}	
      }
      
      // If we have a non-null url, then delegate the rest of the
      // configuration to the OptionConverter.selectAndConfigure
      // method.
      if(url != null) {
	    LogLog.debug("Using URL ["+url+"] for automatic log4j configuration.");
        try {
            OptionConverter.selectAndConfigure(url, configuratorClassName,
					   LogManager.getLoggerRepository());
        } catch (NoClassDefFoundError e) {
            LogLog.warn("Error during default initialization", e);
        }
      } else {
	    LogLog.debug("Could not find resource: ["+configurationOptionStr+"].");
      }
    }  
  
    if((LogManager.guard != null) && (LogManager.guard != guard)) {
      throw new IllegalArgumentException(
           "Attempted to reset the LoggerFactory without possessing the guard.");
    }

    if(selector == null) {
      throw new IllegalArgumentException("RepositorySelector must be non-null.");
    }

    LogManager.guard = guard;
    LogManager.repositorySelector = selector;
public static voidshutdown()

    getLoggerRepository().shutdown();