Package google.registry.util

Class JdkLoggerConfig

java.lang.Object

google.registry.util.JdkLoggerConfig

@CheckReturnValue
public final class JdkLoggerConfig
extends Object

An adapter for the configuration specific aspects of a JDK logger which retains a strong reference to the corresponding underlying logger to prevent accidental garbage collection. This class is needed to help avoid bugs caused by the premature garbage collection of logger instances (which are only weakly referenced when returned by Logger.getLogger(java.lang.String)).

It is important to note that while this class is in the Flogger package, it's not actually a part of the core logging API and will only have any effect if you are using a JDK based logging backend. In general Flogger avoids the issue of defining how logging is configured, but the issues around weakly referenced JDK loggers are so common, and so hard to debug, it was felt necessary to provide an easily available solution for that problem.

All methods in this API simply delegate to the equivalent Logger method without any additional checking.

A small number of small differences exist between using this class and using a Logger instance directly, but these are deliberate and seek to avoid misuse.

• The LoggerConfig API has no "setParent()" method (this should never be called by application code anyway).
• It is not possible to obtain a LoggerConfig instance for an anonymous logger (the LoggerConfig API hides the underlying logger, so it would be impossible to do any logging with such an object). If you are using an anonymous logger then you must continue to configure it via the Logger API itself.
• This API adds the @Nullable annotation to parameters and return values where appropriate.

Method Summary

Modifier and Type	Method	Description
void	addHandler(Handler handler)	See Logger.addHandler(Handler).
static JdkLoggerConfig	getConfig(Class<?> clazz)	Returns a configuration instance suitable for configuring the logger of the specified class.
static JdkLoggerConfig	getConfig(String name)	Returns a configuration instance suitable for configuring a logger with the same name.
Filter	getFilter()	See Logger.getFilter().
Handler[]	getHandlers()	See Logger.getHandlers().
Level	getLevel()	See Logger.getLevel().
String	getName()	See Logger.getName().
static JdkLoggerConfig	getPackageConfig(Class<?> clazz)	Returns a configuration instance suitable for configuring loggers in the same package as the specified class.
Logger	getParent()	See Logger.getParent().
ResourceBundle	getResourceBundle()	See Logger.getResourceBundle().
String	getResourceBundleName()	See Logger.getResourceBundleName().
boolean	getUseParentHandlers()	See Logger.getUseParentHandlers().
void	removeHandler(Handler handler)	See Logger.removeHandler(Handler).
void	setFilter(Filter newFilter)	See Logger.setFilter(Filter).
void	setLevel(Level newLevel)	See Logger.setLevel(Level).
void	setUseParentHandlers(boolean useParentHandlers)	See Logger.setUseParentHandlers(boolean).

Methods inherited from class java.lang.Object

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

Method Details

getConfig

public static JdkLoggerConfig getConfig(Class<?> clazz)

Returns a configuration instance suitable for configuring the logger of the specified class.

This method obtains and wraps the underlying logger for the given class, retaining a strong reference and making it safe to use for persistent configuration changes.

Parameters:

clazz - the class whose logger is to be configured via this API.

getPackageConfig

public static JdkLoggerConfig getPackageConfig(Class<?> clazz)

Returns a configuration instance suitable for configuring loggers in the same package as the specified class.

This method obtains and wraps the underlying logger for the given package, retaining a string reference and making it safe to use for persistent configuration changes.

Parameters:

clazz - a class defining the package for which logger configuration should occur.

getConfig

public static JdkLoggerConfig getConfig(String name)

Returns a configuration instance suitable for configuring a logger with the same name.

This method obtains and wraps the underlying logger with the given name, retaining a strong reference and making it safe to use for persistent configuration changes. Note that as it makes very little sense to have a logger configuration object which wraps (and hides) an anonymous logger instance, null names are disallowed.

Parameters:

name - the name of the logger to be configured via this API.

getResourceBundle

@NullableDecl
public ResourceBundle getResourceBundle()

See Logger.getResourceBundle().

getResourceBundleName

@NullableDecl
public String getResourceBundleName()

See Logger.getResourceBundleName().

setFilter

public void setFilter(@NullableDecl
 Filter newFilter)
               throws SecurityException

See Logger.setFilter(Filter).

Throws:

SecurityException

getFilter

@NullableDecl
public Filter getFilter()

See Logger.getFilter().

setLevel

public void setLevel(@NullableDecl
 Level newLevel)
              throws SecurityException

See Logger.setLevel(Level).

Throws:

SecurityException

getLevel

@NullableDecl
public Level getLevel()

See Logger.getLevel().

getName

public String getName()

See Logger.getName().

addHandler

public void addHandler(Handler handler)
                throws SecurityException

See Logger.addHandler(Handler).

Throws:

SecurityException

removeHandler

public void removeHandler(Handler handler)
                   throws SecurityException

See Logger.removeHandler(Handler).

Throws:

SecurityException

getHandlers

public Handler[] getHandlers()

See Logger.getHandlers().

setUseParentHandlers

public void setUseParentHandlers(boolean useParentHandlers)

See Logger.setUseParentHandlers(boolean).

getUseParentHandlers

public boolean getUseParentHandlers()

See Logger.getUseParentHandlers().

getParent

@NullableDecl
public Logger getParent()

See Logger.getParent().