Package org.apache.log4j.xml

Class XSLTLayout

  • All Implemented Interfaces:
    org.apache.log4j.spi.OptionHandler, org.apache.log4j.xml.UnrecognizedElementHandler
    public final class XSLTLayout
extends org.apache.log4j.Layout
implements org.apache.log4j.xml.UnrecognizedElementHandler
    XSLTLayout transforms each event as a document using a specified or default XSLT transform. The default XSLT transform produces a result similar to XMLLayout.

    When used with a FileAppender or similar, the transformation of an event will be appended to the results for previous transforms. If each transform results in an XML element, then resulting file will only be an XML entity since an XML document requires one and only one top-level element. To process the entity, reference it in a XML document like so: 

      <!DOCTYPE log4j:eventSet [<!ENTITY data SYSTEM "data.xml">]>

  <log4j:eventSet xmlns:log4j="http://jakarta.apache.org/log4j/">
    &data
  </log4j:eventSet>

    The layout will detect the encoding and media-type specified in the transform. If no encoding is specified in the transform, an xsl:output element specifying the US-ASCII encoding will be inserted before processing the transform. If an encoding is specified in the transform, the same encoding should be explicitly specified for the appender.

    Extracting MDC values can be expensive when used with log4j releases prior to 1.2.15. Output of MDC values is enabled by default but be suppressed by setting properties to false.

    Extracting location info can be expensive regardless of log4j version. Output of location info is disabled by default but can be enabled by setting locationInfo to true.

    Embedded transforms in XML configuration should not depend on namespace prefixes defined earlier in the document as namespace aware parsing in not generally performed when using DOMConfigurator. The transform will serialize and reparse to get the namespace aware document needed.

    • Constructor Detail

      • XSLTLayout

        public XSLTLayout()
        Default constructor.

    • Method Detail

      • getContentType

        public String getContentType()
        Overrides:
        getContentType in class org.apache.log4j.Layout

      • setLocationInfo

        public void setLocationInfo​(boolean flag)
        The LocationInfo option takes a boolean value. By default, it is set to false which means there will be no location information output by this layout. If the the option is set to true, then the file name and line number of the statement at the origin of the log statement will be output.

        If you are embedding this layout within an SMTPAppender then make sure to set the LocationInfo option of that appender as well.

        Parameters:
        flag - new value.

      • getLocationInfo

        public boolean getLocationInfo()
        Gets whether location info should be output.
        Returns:
        if location is output.

      • setProperties

        public void setProperties​(boolean flag)
        Sets whether MDC key-value pairs should be output, default false.
        Parameters:
        flag - new value.

      • getProperties

        public boolean getProperties()
        Gets whether MDC key-value pairs should be output.
        Returns:
        true if MDC key-value pairs are output.

      • activateOptions

        public void activateOptions()
        Specified by:
        activateOptions in interface org.apache.log4j.spi.OptionHandler

      • ignoresThrowable

        public boolean ignoresThrowable()
        Gets whether throwables should not be output.
        Specified by:
        ignoresThrowable in class org.apache.log4j.Layout
        Returns:
        true if throwables should not be output.

      • setIgnoresThrowable

        public void setIgnoresThrowable​(boolean ignoresThrowable)
        Sets whether throwables should not be output.
        Parameters:
        ignoresThrowable - if true, throwables should not be output.

      • format

        public String format​(org.apache.log4j.spi.LoggingEvent event)
        Specified by:
        format in class org.apache.log4j.Layout

      • parseUnrecognizedElement

        public boolean parseUnrecognizedElement​(Element element,
                                        Properties props)
                                 throws Exception
        Specified by:
        parseUnrecognizedElement in interface org.apache.log4j.xml.UnrecognizedElementHandler
        Throws:
        Exception