log4j：WARN文档根元素“log4j：configuration”，必须与DOCTYPE根“null”匹配

Question

I want to connect my log4j.xml with log4j.xsd (xml schema). Project don't have any warnings or errors. But when I start it, Ihave such console warnings:

log4j:WARN Continuable parsing error 6 and column 66.

log4j:WARN Document root element "log4j:configuration", must match DOCTYPE root "null".

log4j:WARN Continuable parsing error 6 and column 66.

log4j:WARN Document is invalid: no grammar found.

I think, problem in schema Location. But I don't know, how to write it normally. Hope for your's advices.

My log4j.xml:

  <?xml version="1.0" encoding="UTF-8" ?>

   <log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    debug="false"
    xsi:schemaLocation="http://www.example.org/log4j log4j.xsd ">

<appender name="logFileAppender" class="org.apache.log4j.RollingFileAppender">
        <param name="File" value="E:/Codes/HorseRacing/logFile.log"/>
        <param name="MaxFileSize" value="1MB"/>
        <param name="MaxBackupIndex" value="5"/>
        <param name="Encoding" value="UTF-8"/>
        <layout class="org.apache.log4j.EnhancedPatternLayout">
        <param name="ConversionPattern" value="%d{ISO8601} [%-5p][%-16.16t][%40.40c] - %m%n"/>
        </layout>
    </appender>

     <appender name="ConsoleAppender" class="org.apache.log4j.ConsoleAppender">
        <param name="Encoding" value="Cp866"/>
        <layout class="org.apache.log4j.PatternLayout">
        <param name="ConversionPattern" value="%d{ISO8601} [%-5p][%-25.25l][%10.10c] - %m%n" />
        </layout>
    </appender>

   <logger name="appLogger">
        <level value="INFO"/>
        <appender-ref ref="logFileAppender"/>
        <appender-ref ref="ConsoleAppender"/>
    </logger>

</log4j:configuration>

And my log4j.xsd:

<?xml version="1.0" encoding="UTF-8"?>
<xsd:schema attributeFormDefault="unqualified"
    elementFormDefault="qualified" version="1.0"
    xmlns:xsd="http://www.w3.org/2001/XMLSchema">
    <xsd:element name="configuration">
   <xsd:complexType>
      <xsd:sequence>
        <xsd:element maxOccurs="unbounded" name="appender">
          <xsd:complexType>
            <xsd:sequence>
              <xsd:element maxOccurs="unbounded" name="param">
                <xsd:complexType>
                  <xsd:attribute name="name" type="xsd:string" />
                  <xsd:attribute name="value" type="xsd:string" />
                </xsd:complexType>
              </xsd:element>
              <xsd:element name="layout">
            <xsd:complexType>
              <xsd:sequence>
                <xsd:element name="param">
                  <xsd:complexType>
                    <xsd:attribute name="name" type="xsd:string" />
                    <xsd:attribute name="value" type="xsd:string" />
                  </xsd:complexType>
                </xsd:element>
              </xsd:sequence>
              <xsd:attribute name="class" type="xsd:string" />
            </xsd:complexType>
          </xsd:element>
        </xsd:sequence>
        <xsd:attribute name="name" type="xsd:string" />
        <xsd:attribute name="class" type="xsd:string" />
      </xsd:complexType>
    </xsd:element>
    <xsd:element name="logger">
      <xsd:complexType>
        <xsd:sequence>
          <xsd:element name="level">
            <xsd:complexType>
              <xsd:attribute name="value" type="xsd:string" />
            </xsd:complexType>
          </xsd:element>
          <xsd:element maxOccurs="unbounded" name="appender-ref">
               <xsd:complexType>
                <xsd:attribute name="ref" type="xsd:string" />
               </xsd:complexType>
             </xsd:element>
           </xsd:sequence>
          <xsd:attribute name="name" type="xsd:string" />
         </xsd:complexType>
       </xsd:element>
     </xsd:sequence>
     <xsd:attribute name="debug" type="xsd:boolean" />
     <xsd:attribute name="schemaLocation" type="xsd:string" />
   </xsd:complexType>
  </xsd:element>
   </xsd:schema>

   <logger name="appLogger">
    <level value="INFO"/>
    <appender-ref ref="logFileAppender"/>
    <appender-ref ref="ConsoleAppender"/>
    </logger>

    </log4j:configuration>

PS Sorry for my english...

Answer 1

Add the following line to your log4j.xml config file right after the <xml> element:

<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">

Complete log4j Configuration Example from their wiki:

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">

<log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/">
  <appender name="console" class="org.apache.log4j.ConsoleAppender"> 
    <param name="Target" value="System.out"/> 
    <layout class="org.apache.log4j.PatternLayout"> 
      <param name="ConversionPattern" value="%-5p %c{1} - %m%n"/> 
    </layout> 
  </appender> 

  <root> 
    <priority value ="debug" /> 
    <appender-ref ref="console" /> 
  </root>

</log4j:configuration>

Answer 2

The jar that is producing this message expects to see a DTD validated, not schema validated configuration.

Check your classpath. You are using a too old version of the framework for this configuration. Very likely you have multiple versions of a jar with the same name on your disk, and such occurences will point you to the problem and to removal of very old libraries that you do not really want to use.