Package org.apache.log4j

Class Hierarchy

  • All Implemented Interfaces:
    LoggerRepository, RendererSupport, ThrowableRendererSupport
    public class Hierarchy
extends java.lang.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 Detail

      • Hierarchy

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

    • Method Detail

      • addRenderer

        public void addRenderer​(java.lang.Class classToRender,
                        ObjectRenderer or)
        Add an object renderer for a specific class.

      • 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

      • exists

        public Logger exists​(java.lang.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​(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.

      • getLogger

        public Logger getLogger​(java.lang.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​(java.lang.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 java.util.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

      • 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​(java.lang.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​(java.lang.String override)
        Deprecated.
        Deprecated with no replacement.
        Does nothing.

      • setRenderer

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

      • 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