Class Hierarchy

java.lang.Object
org.apache.log4j.Hierarchy
All Implemented Interfaces:
LoggerRepository, RendererSupport, ThrowableRendererSupport

public class Hierarchy extends Object implements LoggerRepository, RendererSupport, ThrowableRendererSupport
This class is specialized in retrieving loggers by name and also maintaining the logger hierarchy.

The casual user does not have to deal with this class directly.

The structure of the logger hierarchy is maintained by the getLogger(java.lang.String) method. The hierarchy is such that children link to their parent but parents do not have any pointers to their children. Moreover, loggers can be instantiated in any order, in particular descendant before ancestor.

In case a descendant is created before a particular ancestor, then it creates a provision node for the ancestor and adds itself to the provision node. Other descendants of the same ancestor add themselves to the previously created provision node.

Author:
Ceki Gülcü
  • Constructor Details

    • Hierarchy

      public Hierarchy(Logger root)
      Create a new logger hierarchy.
      Parameters:
      root - The root of the new hierarchy.
  • Method Details

    • addRenderer

      public void addRenderer(Class classToRender, ObjectRenderer or)
      Add an object renderer for a specific class.
    • addHierarchyEventListener

      public void addHierarchyEventListener(HierarchyEventListener listener)
      Description copied from interface: LoggerRepository
      Add a HierarchyEventListener event to the repository.
      Specified by:
      addHierarchyEventListener in interface LoggerRepository
    • clear

      public void clear()
      This call will clear all logger definitions from the internal hashtable. Invoking this method will irrevocably mess up the logger hierarchy.

      You should really know what you are doing before invoking this method.

      Since:
      0.9.0
    • emitNoAppenderWarning

      public void emitNoAppenderWarning(Category cat)
      Specified by:
      emitNoAppenderWarning in interface LoggerRepository
    • exists

      public Logger exists(String name)
      Check if the named logger exists in the hierarchy. If so return its reference, otherwise returns null.
      Specified by:
      exists in interface LoggerRepository
      Parameters:
      name - The name of the logger to search for.
    • setThreshold

      public void setThreshold(String levelStr)
      The string form of setThreshold(Level).
      Specified by:
      setThreshold in interface LoggerRepository
    • setThreshold

      public void setThreshold(Level l)
      Enable logging for logging requests with level l or higher. By default all levels are enabled.
      Specified by:
      setThreshold in interface LoggerRepository
      Parameters:
      l - The minimum level for which logging requests are sent to their appenders.
    • fireAddAppenderEvent

      public void fireAddAppenderEvent(Category logger, Appender appender)
      Specified by:
      fireAddAppenderEvent in interface LoggerRepository
    • getThreshold

      public Level getThreshold()
      Returns a Level representation of the enable state.
      Specified by:
      getThreshold in interface LoggerRepository
      Since:
      1.2
    • getLogger

      public Logger getLogger(String name)
      Return a new logger instance named as the first parameter using the default factory.

      If a logger of that name already exists, then it will be returned. Otherwise, a new logger will be instantiated and then linked with its existing ancestors as well as children.

      Specified by:
      getLogger in interface LoggerRepository
      Parameters:
      name - The name of the logger to retrieve.
    • getLogger

      public Logger getLogger(String name, LoggerFactory factory)
      Return a new logger instance named as the first parameter using factory.

      If a logger of that name already exists, then it will be returned. Otherwise, a new logger will be instantiated by the factory parameter and linked with its existing ancestors as well as children.

      Specified by:
      getLogger in interface LoggerRepository
      Parameters:
      name - The name of the logger to retrieve.
      factory - The factory that will make the new logger instance.
    • getCurrentLoggers

      public Enumeration getCurrentLoggers()
      Returns all the currently defined categories in this hierarchy as an Enumeration.

      The root logger is not included in the returned Enumeration.

      Specified by:
      getCurrentLoggers in interface LoggerRepository
    • getCurrentCategories

      public Enumeration getCurrentCategories()
      Deprecated.
      Please use getCurrentLoggers() instead.
      Description copied from interface: LoggerRepository
      Deprecated. Please use LoggerRepository.getCurrentLoggers() instead.
      Specified by:
      getCurrentCategories in interface LoggerRepository
    • getRendererMap

      public RendererMap getRendererMap()
      Get the renderer map for this hierarchy.
      Specified by:
      getRendererMap in interface RendererSupport
    • getRootLogger

      public Logger getRootLogger()
      Get the root of this hierarchy.
      Specified by:
      getRootLogger in interface LoggerRepository
      Since:
      0.9.0
    • isDisabled

      public boolean isDisabled(int level)
      This method will return true if this repository is disabled for level object passed as parameter and false otherwise. See also the threshold emthod.
      Specified by:
      isDisabled in interface LoggerRepository
    • overrideAsNeeded

      public void overrideAsNeeded(String override)
      Deprecated.
      Deprecated with no replacement.
    • resetConfiguration

      public void resetConfiguration()
      Reset all values contained in this hierarchy instance to their default. This removes all appenders from all categories, sets the level of all non-root categories to null, sets their additivity flag to true and sets the level of the root logger to DEBUG. Moreover, message disabling is set its default "off" value.

      Existing categories are not removed. They are just reset.

      This method should be used sparingly and with care as it will block all logging until it is completed.

      Specified by:
      resetConfiguration in interface LoggerRepository
      Since:
      0.8.5
    • setDisableOverride

      public void setDisableOverride(String override)
      Deprecated.
      Deprecated with no replacement.
      Does nothing.
    • setRenderer

      public void setRenderer(Class renderedClass, ObjectRenderer renderer)
      Used by subclasses to add a renderer to the hierarchy passed as parameter.
      Specified by:
      setRenderer in interface RendererSupport
    • setThrowableRenderer

      public void setThrowableRenderer(ThrowableRenderer renderer)
      Set throwable renderer.
      Specified by:
      setThrowableRenderer in interface ThrowableRendererSupport
      Parameters:
      renderer - renderer, may be null.
    • getThrowableRenderer

      public ThrowableRenderer getThrowableRenderer()
      Get throwable renderer.
      Specified by:
      getThrowableRenderer in interface ThrowableRendererSupport
      Returns:
      throwable renderer, may be null.
    • shutdown

      public void shutdown()
      Shutting down a hierarchy will safely close and remove all appenders in all categories including the root logger.

      Some appenders such as SocketAppender and AsyncAppender need to be closed before the application exists. Otherwise, pending logging events might be lost.

      The shutdown method is careful to close nested appenders before closing regular appenders. This is allows configurations where a regular appender is attached to a logger and again to a nested appender.

      Specified by:
      shutdown in interface LoggerRepository
      Since:
      1.0