org.apache.log4j.xml

Class DOMConfigurator

java.lang.Object

org.apache.log4j.xml.DOMConfigurator

All Implemented Interfaces:

Configurator

public class DOMConfigurator
extends Object
implements Configurator

Use this class to initialize the log4j environment using a DOM tree.

The DTD is specified in log4j.dtd.

Sometimes it is useful to see how log4j is reading configuration files. You can enable log4j internal logging by defining the log4j.debug variable on the java command line. Alternatively, set the debug attribute in the log4j:configuration element. As in

   <log4j:configuration debug="true" xmlns:log4j="http://jakarta.apache.org/log4j/">
   ...
   </log4j:configuration>

There are sample XML files included in the package.

Since:

0.8.3

Author:

Christopher Taylor, Ceki Gülcü, Anders Kristensen

Field Summary

Fields

Modifier and Type	Field and Description
protected LoggerFactory	catFactory

Fields inherited from interface org.apache.log4j.spi.Configurator

INHERITED, NULL

Constructor Summary

Constructors

Constructor and Description
DOMConfigurator() No argument constructor.

Method Summary

Methods

Modifier and Type	Method and Description
static void	configure(Element element) Configure log4j using a configuration element as defined in the log4j.dtd.
static void	configure(String filename) A static version of doConfigure(String, LoggerRepository).
static void	configure(URL url) A static version of doConfigure(URL, LoggerRepository).
static void	configureAndWatch(String configFilename) Like configureAndWatch(String, long) except that the default delay as defined by FileWatchdog.DEFAULT_DELAY is used.
static void	configureAndWatch(String configFilename, long delay) Read the configuration file configFilename if it exists.
void	doConfigure(Element element, LoggerRepository repository) Configure by taking in an DOM element.
protected void	doConfigure(InputSource inputSource, LoggerRepository repository) Configure log4j by reading in a log4j.dtd compliant XML configuration file.
void	doConfigure(InputStream inputStream, LoggerRepository repository) Configure log4j by reading in a log4j.dtd compliant XML configuration file.
void	doConfigure(Reader reader, LoggerRepository repository) Configure log4j by reading in a log4j.dtd compliant XML configuration file.
void	doConfigure(String filename, LoggerRepository repository)
void	doConfigure(URL url, LoggerRepository repository) Interpret a resource pointed by a URL and set up log4j accordingly.
protected Appender	findAppenderByName(Document doc, String appenderName) Used internally to parse appenders by IDREF name.
protected Appender	findAppenderByReference(Element appenderRef) Used internally to parse appenders by IDREF element.
protected void	parse(Element element) Used internally to configure the log4j framework by parsing a DOM tree of XML elements based on log4j.dtd.
protected Appender	parseAppender(Element appenderElement) Used internally to parse an appender element.
protected void	parseCategory(Element loggerElement) Used internally to parse an category element.
protected void	parseCategoryFactory(Element factoryElement) Used internally to parse the category factory element.
protected void	parseChildrenOfLoggerElement(Element catElement, Logger cat, boolean isRoot) Used internally to parse the children of a category element.
static Object	parseElement(Element element, Properties props, Class expectedClass) Creates an object and processes any nested param elements but does not call activateOptions.
protected void	parseErrorHandler(Element element, Appender appender) Used internally to parse an ErrorHandler element.
protected void	parseFilters(Element element, Appender appender) Used internally to parse a filter element.
protected Layout	parseLayout(Element layout_element) Used internally to parse a layout element.
protected void	parseLevel(Element element, Logger logger, boolean isRoot) Used internally to parse a level element.
protected void	parseRenderer(Element element)
protected void	parseRoot(Element rootElement) Used internally to parse the roor category element.
protected ThrowableRenderer	parseThrowableRenderer(Element element) Parses throwable renderer.
protected void	setParameter(Element elem, PropertySetter propSetter)
static void	setParameter(Element elem, PropertySetter propSetter, Properties props) Sets a parameter based from configuration file content.
protected String	subst(String value)
static String	subst(String value, Properties props) Substitutes property value for any references in expression.

Methods inherited from class java.lang.Object

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

Field Detail

catFactory

protected LoggerFactory catFactory

Constructor Detail

DOMConfigurator

public DOMConfigurator()

No argument constructor.

Method Detail

findAppenderByName

protected Appender findAppenderByName(Document doc,
                          String appenderName)

Used internally to parse appenders by IDREF name.

findAppenderByReference

protected Appender findAppenderByReference(Element appenderRef)

Used internally to parse appenders by IDREF element.

parseAppender

protected Appender parseAppender(Element appenderElement)

Used internally to parse an appender element.

parseErrorHandler

protected void parseErrorHandler(Element element,
                     Appender appender)

Used internally to parse an ErrorHandler element.

parseFilters

protected void parseFilters(Element element,
                Appender appender)

Used internally to parse a filter element.

parseCategory

protected void parseCategory(Element loggerElement)

Used internally to parse an category element.

parseCategoryFactory

protected void parseCategoryFactory(Element factoryElement)

Used internally to parse the category factory element.

parseRoot

protected void parseRoot(Element rootElement)

Used internally to parse the roor category element.

parseChildrenOfLoggerElement

protected void parseChildrenOfLoggerElement(Element catElement,
                                Logger cat,
                                boolean isRoot)

Used internally to parse the children of a category element.

parseLayout

protected Layout parseLayout(Element layout_element)

Used internally to parse a layout element.

parseRenderer

protected void parseRenderer(Element element)

parseThrowableRenderer

protected ThrowableRenderer parseThrowableRenderer(Element element)

Parses throwable renderer.

Parameters:

element - throwableRenderer element.

Returns:

configured throwable renderer.

Since:

1.2.16.

parseLevel

protected void parseLevel(Element element,
              Logger logger,
              boolean isRoot)

Used internally to parse a level element.

setParameter

protected void setParameter(Element elem,
                PropertySetter propSetter)

configure

public static void configure(Element element)

Configure log4j using a configuration element as defined in the log4j.dtd.

configureAndWatch

public static void configureAndWatch(String configFilename)

Like configureAndWatch(String, long) except that the default delay as defined by FileWatchdog.DEFAULT_DELAY is used.

Parameters:

configFilename - A log4j configuration file in XML format.

configureAndWatch

public static void configureAndWatch(String configFilename,
                     long delay)

Read the configuration file configFilename if it exists. Moreover, a thread will be created that will periodically check if configFilename has been created or modified. The period is determined by the delay argument. If a change or file creation is detected, then configFilename is read to configure log4j.

Parameters:

configFilename - A log4j configuration file in XML format.

delay - The delay in milliseconds to wait between each check.

doConfigure

public void doConfigure(String filename,
               LoggerRepository repository)

doConfigure

public void doConfigure(URL url,
               LoggerRepository repository)

Description copied from interface: Configurator

Interpret a resource pointed by a URL and set up log4j accordingly. The configuration is done relative to the hierarchy parameter.

Specified by:

doConfigure in interface Configurator

Parameters:

url - The URL to parse

repository - The hierarchy to operation upon.

doConfigure

public void doConfigure(InputStream inputStream,
               LoggerRepository repository)
                 throws FactoryConfigurationError

Configure log4j by reading in a log4j.dtd compliant XML configuration file.

Specified by:

doConfigure in interface Configurator

Parameters:

inputStream - The InputStream to parse

repository - The hierarchy to operation upon.

Throws:

FactoryConfigurationError

doConfigure

public void doConfigure(Reader reader,
               LoggerRepository repository)
                 throws FactoryConfigurationError

Configure log4j by reading in a log4j.dtd compliant XML configuration file.

Throws:

FactoryConfigurationError

doConfigure

protected void doConfigure(InputSource inputSource,
               LoggerRepository repository)
                    throws FactoryConfigurationError

Configure log4j by reading in a log4j.dtd compliant XML configuration file.

Throws:

FactoryConfigurationError

doConfigure

public void doConfigure(Element element,
               LoggerRepository repository)

Configure by taking in an DOM element.

configure

public static void configure(String filename)
                      throws FactoryConfigurationError

A static version of doConfigure(String, LoggerRepository).

Throws:

FactoryConfigurationError

configure

public static void configure(URL url)
                      throws FactoryConfigurationError

A static version of doConfigure(URL, LoggerRepository).

Throws:

FactoryConfigurationError

parse

protected void parse(Element element)

Used internally to configure the log4j framework by parsing a DOM tree of XML elements based on log4j.dtd.

subst

protected String subst(String value)

subst

public static String subst(String value,
           Properties props)

Substitutes property value for any references in expression.

Parameters:

value - value from configuration file, may contain literal text, property references or both

props - properties.

Returns:

evaluated expression, may still contain expressions if unable to expand.

Since:

1.2.15

setParameter

public static void setParameter(Element elem,
                PropertySetter propSetter,
                Properties props)

Sets a parameter based from configuration file content.

Parameters:

elem - param element, may not be null.

propSetter - property setter, may not be null.

props - properties

Since:

1.2.15

parseElement

public static Object parseElement(Element element,
                  Properties props,
                  Class expectedClass)
                           throws Exception

Creates an object and processes any nested param elements but does not call activateOptions. If the class also supports UnrecognizedElementParser, the parseUnrecognizedElement method will be call for any child elements other than param.

Parameters:

element - element, may not be null.

props - properties

expectedClass - interface or class expected to be implemented by created class

Returns:

created class or null.

Throws:

Exception - thrown if the contain object should be abandoned.

Since:

1.2.15