abstract public String format(LoggingEvent event)
Implement this method to create your own layout format.

 public String getContentType() 
{
                 
    return "text/plain";
}

Returns the content type output by this layout. The base class returns "text/plain".

 public String getFooter() 
{
    return null;
}

Returns the footer for the layout format. The base class returns null.

 public String getHeader() 
{
    return null;
}

Returns the header for the layout format. The base class returns null.

 abstract public boolean ignoresThrowable()
If the layout handles the throwable object contained within
LoggingEvent , then the layout should return
false. Otherwise, if the layout ignores throwable
object, then the layout should return true.

The SimpleLayout , TTCCLayout , PatternLayout  all return true. The org.apache.log4j.xml.XMLLayout  returns false.