- java.lang.Object
- java.util.logging.Formatter
- java.util.logging.XMLFormatter
public class XMLFormatter extends Formatter
Format a LogRecord into a standard XML format.The DTD specification is provided as Appendix A to the Java Logging APIs specification.
The XMLFormatter can be used with arbitrary character encodings, but it is recommended that it normally be used with UTF-8. The character encoding can be set on the output Handler.
- Implementation Requirements:
- Since JDK 9, instances of LogRecord contain an
Instant
which can have nanoseconds below the millisecond resolution. The DTD specification has been updated to allow for an optional<nanos>
element. By default, the XMLFormatter will compute the nanosecond adjustment below the millisecond resolution (usingLogRecord.getInstant().getNano() % 1000_000
) - and if this is not 0, this adjustment value will be printed in the new<nanos>
element. The event instant can then be reconstructed usingInstant.ofEpochSecond(millis/1000L, (millis % 1000L) * 1000_000L + nanos)
wheremillis
andnanos
represent the numbers serialized in the<millis>
and<nanos>
elements, respectively.
The<date>
element will now contain the whole instant as formatted by theDateTimeFormatter.ISO_INSTANT
formatter.For compatibility with old parsers, XMLFormatters can be configured to revert to the old format by specifying a
<xml-formatter-fully-qualified-class-name>.useInstant = false
property in the logging configuration. WhenuseInstant
isfalse
, the old formatting will be preserved. WhenuseInstant
istrue
(the default), the<nanos>
element will be printed and the<date>
element will contain the formatted instant.For instance, in order to configure plain instances of XMLFormatter to omit the new
<nano>
element,java.util.logging.XMLFormatter.useInstant = false
can be specified in the logging configuration. - Since:
- 1.4
Constructor Summary
Constructors Constructor Description XMLFormatter()
Creates a new instance of XMLFormatter.
Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description String
format(LogRecord record)
Format the given message to XML.String
getHead(Handler h)
Return the header string for a set of XML formatted records.String
getTail(Handler h)
Return the tail string for a set of XML formatted records.Methods declared in class java.util.logging.Formatter
formatMessage
Constructor Detail
XMLFormatter
public XMLFormatter()
Creates a new instance of XMLFormatter.- Implementation Requirements:
- Since JDK 9, the XMLFormatter will print out the record event time as an Instant. This instant has the best resolution available on the system. The
<date>
element will contain the instant as formatted by theDateTimeFormatter.ISO_INSTANT
. In addition, an optional<nanos>
element containing a nanosecond adjustment will be printed if the instant contains some nanoseconds below the millisecond resolution.This new behavior can be turned off, and the old formatting restored, by specifying a property in the logging configuration. If
LogManager.getLogManager().getProperty( this.getClass().getName()+".useInstant")
is"false"
or"0"
, the old formatting will be restored.
Method Detail
format
public String format(LogRecord record)
Format the given message to XML.This method can be overridden in a subclass. It is recommended to use the
Formatter.formatMessage(java.util.logging.LogRecord)
convenience method to localize and format the message field.
getHead
public String getHead(Handler h)
Return the header string for a set of XML formatted records.