<?xml version="1.0" encoding="UTF-8" ?>
        <!--
  ~ Licensed to the Apache Software Foundation (ASF) under one
  ~ or more contributor license agreements.  See the NOTICE file
  ~ distributed with this work for additional information
  ~ regarding copyright ownership.  The ASF licenses this file
  ~ to you under the Apache License, Version 2.0 (the
  ~ "License"); you may not use this file except in compliance
  ~ with the License.  You may obtain a copy of the License at
  ~
  ~     http://www.apache.org/licenses/LICENSE-2.0
  ~
  ~ Unless required by applicable law or agreed to in writing, software
  ~ distributed under the License is distributed on an "AS IS" BASIS,
  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  ~ See the License for the specific language governing permissions and
  ~ limitations under the License.
  -->

        <!ELEMENT log4j:configuration (renderer*, throwableRenderer?,
                appender*,plugin*, (category|logger)*,root?,
                (categoryFactory|loggerFactory)?)>

        <!-- The "threshold" attribute takes a level value below which -->
        <!-- all logging statements are disabled. -->

        <!-- Setting the "debug" enable the printing of internal log4j logging   -->
        <!-- statements.                                                         -->

        <!-- By default, debug attribute is "null", meaning that we not do touch -->
        <!-- internal log4j logging settings. The "null" value for the threshold -->
        <!-- attribute can be misleading. The threshold field of a repository	 -->
        <!-- cannot be set to null. The "null" value for the threshold attribute -->
        <!-- simply means don't touch the threshold field, the threshold field   -->
        <!-- keeps its old value.                                                -->

        <!ATTLIST log4j:configuration
                xmlns:log4j              CDATA #FIXED "http://jakarta.apache.org/log4j/"
                threshold                (all|trace|debug|info|warn|error|fatal|off|null) "null"
                debug                    (true|false|null)  "null"
                reset                    (true|false) "false"
                >

        <!-- renderer elements allow the user to customize the conversion of  -->
        <!-- message objects to String.                                       -->

        <!ELEMENT renderer EMPTY>
        <!ATTLIST renderer
                renderedClass  CDATA #REQUIRED
                renderingClass CDATA #REQUIRED
                >

        <!--  throwableRenderer allows the user to customize the conversion
                 of exceptions to a string representation.  -->
        <!ELEMENT throwableRenderer (param*)>
        <!ATTLIST throwableRenderer
                class  CDATA #REQUIRED
                >


        <!-- Appenders must have a name and a class. -->
        <!-- Appenders may contain an error handler, a layout, optional parameters -->
        <!-- and filters. They may also reference (or include) other appenders. -->
        <!ELEMENT appender (errorHandler?, param*,
                rollingPolicy?, triggeringPolicy?, connectionSource?,
                layout?, filter*, appender-ref*)>
        <!ATTLIST appender
                name 		CDATA 	#REQUIRED
                class 	CDATA	#REQUIRED
                >

        <!ELEMENT layout (param*)>
        <!ATTLIST layout
                class		CDATA	#REQUIRED
                >

        <!ELEMENT filter (param*)>
        <!ATTLIST filter
                class		CDATA	#REQUIRED
                >

        <!-- ErrorHandlers can be of any class. They can admit any number of -->
        <!-- parameters. -->

        <!ELEMENT errorHandler (param*, root-ref?, logger-ref*,  appender-ref?)>
        <!ATTLIST errorHandler
                class        CDATA   #REQUIRED
                >

        <!ELEMENT root-ref EMPTY>

        <!ELEMENT logger-ref EMPTY>
        <!ATTLIST logger-ref
                ref CDATA #REQUIRED
                >

        <!ELEMENT param EMPTY>
        <!ATTLIST param
                name		CDATA   #REQUIRED
                value		CDATA	#REQUIRED
                >


        <!-- The priority class is org.apache.log4j.Level by default -->
        <!ELEMENT priority (param*)>
        <!ATTLIST priority
                class   CDATA	#IMPLIED
                value	  CDATA #REQUIRED
                >

        <!-- The level class is org.apache.log4j.Level by default -->
        <!ELEMENT level (param*)>
        <!ATTLIST level
                class   CDATA	#IMPLIED
                value	  CDATA #REQUIRED
                >


        <!-- If no level element is specified, then the configurator MUST not -->
        <!-- touch the level of the named category. -->
        <!ELEMENT category (param*,(priority|level)?,appender-ref*)>
        <!ATTLIST category
                class         CDATA   #IMPLIED
                name		CDATA	#REQUIRED
                additivity	(true|false) "true"
                >

        <!-- If no level element is specified, then the configurator MUST not -->
        <!-- touch the level of the named logger. -->
        <!ELEMENT logger (param*,level?,appender-ref*)>
        <!ATTLIST logger
                class         CDATA   #IMPLIED
                name		CDATA	#REQUIRED
                additivity	(true|false) "true"
                >


        <!ELEMENT categoryFactory (param*)>
        <!ATTLIST categoryFactory
                class        CDATA #REQUIRED>

        <!ELEMENT loggerFactory (param*)>
        <!ATTLIST loggerFactory
                class        CDATA #REQUIRED>

        <!ELEMENT appender-ref EMPTY>
        <!ATTLIST appender-ref
                ref CDATA #REQUIRED
                >

        <!-- plugins must have a name and class and can have optional parameters -->
        <!ELEMENT plugin (param*, connectionSource?)>
        <!ATTLIST plugin
                name 		CDATA 	   #REQUIRED
                class 	CDATA  #REQUIRED
                >

        <!ELEMENT connectionSource (dataSource?, param*)>
        <!ATTLIST connectionSource
                class        CDATA  #REQUIRED
                >

        <!ELEMENT dataSource (param*)>
        <!ATTLIST dataSource
                class        CDATA  #REQUIRED
                >

        <!ELEMENT triggeringPolicy ((param|filter)*)>
        <!ATTLIST triggeringPolicy
                name 		CDATA  #IMPLIED
                class 	CDATA  #REQUIRED
                >

        <!ELEMENT rollingPolicy (param*)>
        <!ATTLIST rollingPolicy
                name 		CDATA  #IMPLIED
                class 	CDATA  #REQUIRED
                >


        <!-- If no priority element is specified, then the configurator MUST not -->
        <!-- touch the priority of root. -->
        <!-- The root category always exists and cannot be subclassed. -->
        <!ELEMENT root (param*, (priority|level)?, appender-ref*)>


        <!-- ==================================================================== -->
        <!--                       A logging event                                -->
        <!-- ==================================================================== -->
        <!ELEMENT log4j:eventSet (log4j:event*)>
        <!ATTLIST log4j:eventSet
                xmlns:log4j             CDATA #FIXED "http://jakarta.apache.org/log4j/"
                version                (1.1|1.2) "1.2"
                includesLocationInfo   (true|false) "true"
                >


        <!ELEMENT log4j:event (log4j:message, log4j:NDC?, log4j:throwable?,
                log4j:locationInfo?, log4j:properties?) >

        <!-- The timestamp format is application dependent. -->
        <!ATTLIST log4j:event
                logger     CDATA #REQUIRED
                level      CDATA #REQUIRED
                thread     CDATA #REQUIRED
                timestamp  CDATA #REQUIRED
                time       CDATA #IMPLIED
                >

        <!ELEMENT log4j:message (#PCDATA)>
        <!ELEMENT log4j:NDC (#PCDATA)>

        <!ELEMENT log4j:throwable (#PCDATA)>

        <!ELEMENT log4j:locationInfo EMPTY>
        <!ATTLIST log4j:locationInfo
                class  CDATA	#REQUIRED
                method CDATA	#REQUIRED
                file   CDATA	#REQUIRED
                line   CDATA	#REQUIRED
                >

        <!ELEMENT log4j:properties (log4j:data*)>

        <!ELEMENT log4j:data EMPTY>
        <!ATTLIST log4j:data
                name   CDATA	#REQUIRED
                value  CDATA	#REQUIRED
                >