Class XMLFormatter

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 (using LogRecord.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 using Instant.ofEpochSecond(millis/1000L, (millis % 1000L) * 1000_000L + nanos) where millis and nanos represent the numbers serialized in the <millis> and <nanos> elements, respectively.
The <date> element will now contain the whole instant as formatted by the DateTimeFormatter.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. When useInstant is false, the old formatting will be preserved. When useInstant is true (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

Constructor	Description
`XMLFormatter()`	Creates a new instance of XMLFormatter.

Method Summary

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 Formatter

formatMessage

Modifier and Type	Method	Description
`String`	`formatMessage(LogRecord record)`	Localize and format the message string from a log record.

Methods declared in class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Modifier and Type	Method	Description
`protected Object`	`clone()`	Creates and returns a copy of this object.
`boolean`	`equals(Object obj)`	Indicates whether some other object is "equal to" this one.
`protected void`	`finalize()`	Deprecated, for removal: This API element is subject to removal in a future version. Finalization is deprecated and subject to removal in a future release.
`final Class<?>`	`getClass()`	Returns the runtime class of this `Object`.
`int`	`hashCode()`	Returns a hash code value for this object.
`final void`	`notify()`	Wakes up a single thread that is waiting on this object's monitor.
`final void`	`notifyAll()`	Wakes up all threads that are waiting on this object's monitor.
`String`	`toString()`	Returns a string representation of the object.
`final void`	`wait()`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted.
`final void`	`wait(long timeoutMillis)`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait(long timeoutMillis, int nanos)`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

Constructor Details

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 the DateTimeFormatter.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 Details

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(LogRecord) convenience method to localize and format the message field.

Specified by:: format in class Formatter
Parameters:: record - the log record to be formatted.
Returns:: a formatted log record

getHead

public String getHead(Handler h)

Return the header string for a set of XML formatted records.

Overrides:: getHead in class Formatter
Parameters:: h - The target handler (can be null)
Returns:: a valid XML string

getTail

public String getTail(Handler h)

Return the tail string for a set of XML formatted records.

Overrides:: getTail in class Formatter
Parameters:: h - The target handler (can be null)
Returns:: a valid XML string

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