Class XSLTLayout

java.lang.Object
org.apache.log4j.Layout
org.apache.log4j.extras.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
This class is identical to org.apache.log4j.xml.XSLTLayout except for a change in package to aid in use with OSGi. 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.

  • Field Details

    • XSLT_NS

      private static final String XSLT_NS
      Namespace for XSLT.
      See Also:

    • LOG4J_NS

      private static final String LOG4J_NS
      Namespace for log4j events.
      See Also:

    • locationInfo

      private boolean locationInfo
      Whether location information should be written.

    • mediaType

      private String mediaType
      media-type (mime type) extracted from XSLT transform.

    • encoding

      private Charset encoding
      Encoding extracted from XSLT transform.

    • transformerFactory

      private SAXTransformerFactory transformerFactory
      Transformer factory.

    • templates

      private Templates templates
      XSLT templates.

    • outputStream

      private final ByteArrayOutputStream outputStream
      Output stream.

    • ignoresThrowable

      private boolean ignoresThrowable
      Whether throwable information should be ignored.

    • properties

      private boolean properties
      Whether properties should be extracted.

    • activated

      private boolean activated
      Whether activateOptions has been called.

    • utcDateFormat

      private final org.apache.log4j.pattern.CachedDateFormat utcDateFormat
      DateFormat for UTC time.

  • Constructor Details

    • XSLTLayout

      public XSLTLayout()
      Default constructor.

  • Method Details

    • 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

    • setTransform

      public void setTransform(Document xsltdoc) throws TransformerConfigurationException
      Sets XSLT transform.
      Parameters:
      xsltdoc - DOM document containing XSLT transform source, may be modified.
      Throws:
      TransformerConfigurationException - if transformer can not be created.

    • parseUnrecognizedElement

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