Class Provider

java.lang.Object

org.apache.logging.log4j.spi.Provider

Direct Known Subclasses:

JULProvider, Log4jProvider, SimpleProvider, SLF4JProvider

@NullMarked
public class Provider
extends Object

Service class used to bind the Log4j API with an implementation.

Implementors should register an implementation of this class with ServiceLoader.

Deprecated: the automatic registration of providers from META-INF/log4j-provider.properties is supported for compatibility reasons. Support for this file will be dropped in a future version.

Field Summary

Fields

Modifier and Type	Field	Description
private final WeakReference<ClassLoader>	classLoader	Deprecated.
private final @Nullable String	className	Deprecated.
protected static final String	CURRENT_VERSION	Constant inlined by the compiler
private static final int	DEFAULT_PRIORITY
private static final String	DISABLE_CONTEXT_MAP
private static final String	DISABLE_THREAD_CONTEXT
static final String	FACTORY_PRIORITY	Deprecated. since 2.24.0
private static final Logger	LOGGER
static final String	LOGGER_CONTEXT_FACTORY	Deprecated. since 2.24.0
private final @Nullable Class<? extends LoggerContextFactory>	loggerContextFactoryClass
private final int	priority
static final String	PROVIDER_PROPERTY_NAME	System property used to specify the class name of the provider to use.
static final String	THREAD_CONTEXT_MAP	Deprecated. since 2.24.0
private final @Nullable String	threadContextMap	Deprecated.
private final @Nullable Class<? extends ThreadContextMap>	threadContextMapClass
private final @Nullable URL	url	Deprecated.
private final @Nullable String	versions

Constructor Summary

Constructors

Constructor	Description
Provider(@Nullable Integer priority, String versions)
Provider(@Nullable Integer priority, String versions, @Nullable Class<? extends LoggerContextFactory> loggerContextFactoryClass)
Provider(@Nullable Integer priority, String versions, @Nullable Class<? extends LoggerContextFactory> loggerContextFactoryClass, @Nullable Class<? extends ThreadContextMap> threadContextMapClass)
Provider(Properties props, URL url, ClassLoader classLoader)	Deprecated. since 2.24.0

Method Summary

Modifier and Type	Method	Description
boolean	equals(Object o)
@Nullable String	getClassName()	Gets the class name of the LoggerContextFactory implementation of this Provider.
LoggerContextFactory	getLoggerContextFactory()
Integer	getPriority()	Gets the priority (natural ordering) of this Provider.
@Nullable String	getThreadContextMap()	Gets the class name of the ThreadContextMap implementation of this Provider.
ThreadContextMap	getThreadContextMapInstance()
@Nullable URL	getUrl()	Deprecated. since 2.24.0, without a replacement.
String	getVersions()	Returns the Log4j API versions supported by the implementation.
int	hashCode()
@Nullable Class<? extends LoggerContextFactory>	loadLoggerContextFactory()	Loads the LoggerContextFactory class specified by this Provider.
@Nullable Class<? extends ThreadContextMap>	loadThreadContextMap()	Loads the ThreadContextMap class specified by this Provider.
String	toString()

Methods inherited from class Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Details

CURRENT_VERSION

protected static final String CURRENT_VERSION

Constant inlined by the compiler

Since:

2.24.0

See Also:

• Constant Field Values

FACTORY_PRIORITY

@Deprecated
public static final String FACTORY_PRIORITY

Deprecated.

since 2.24.0

Property name to set for a Log4j 2 provider to specify the priority of this implementation.

Since:

2.0.1

See Also:

• Constant Field Values

THREAD_CONTEXT_MAP

@Deprecated
public static final String THREAD_CONTEXT_MAP

Deprecated.

since 2.24.0

Property name to set to the implementation of ThreadContextMap.

Since:

2.0.1

See Also:

• Constant Field Values

LOGGER_CONTEXT_FACTORY

@Deprecated
public static final String LOGGER_CONTEXT_FACTORY

Deprecated.

since 2.24.0

Property name to set to the implementation of LoggerContextFactory.

Since:

2.0.1

See Also:

• Constant Field Values

PROVIDER_PROPERTY_NAME

public static final String PROVIDER_PROPERTY_NAME

System property used to specify the class name of the provider to use.

Since:

2.24.0

See Also:

• Constant Field Values

DISABLE_CONTEXT_MAP

private static final String DISABLE_CONTEXT_MAP

See Also:

• Constant Field Values

DISABLE_THREAD_CONTEXT

private static final String DISABLE_THREAD_CONTEXT

See Also:

• Constant Field Values

DEFAULT_PRIORITY

private static final int DEFAULT_PRIORITY

See Also:

• Constant Field Values

LOGGER

private static final Logger LOGGER

priority

private final int priority

className

@Deprecated
private final @Nullable String className

Deprecated.

loggerContextFactoryClass

private final @Nullable Class<? extends LoggerContextFactory> loggerContextFactoryClass

threadContextMap

@Deprecated
private final @Nullable String threadContextMap

Deprecated.

threadContextMapClass

private final @Nullable Class<? extends ThreadContextMap> threadContextMapClass

versions

private final @Nullable String versions

url

@Deprecated
private final @Nullable URL url

Deprecated.

classLoader

@Deprecated
private final WeakReference<ClassLoader> classLoader

Deprecated.

Constructor Details

Provider

@Deprecated
public Provider(Properties props,
 URL url,
 ClassLoader classLoader)

Deprecated.

since 2.24.0

Constructor used by the deprecated META-INF/log4j-provider.properties format.

Since:

2.0.1

Provider

public Provider(@Nullable Integer priority,
 String versions)

Parameters:

priority - A positive number specifying the provider's priority or null if default,

versions - Minimal API version required, should be set to CURRENT_VERSION.

Since:

2.24.0

Provider

public Provider(@Nullable Integer priority,
 String versions,
 @Nullable Class<? extends LoggerContextFactory> loggerContextFactoryClass)

Parameters:

priority - A positive number specifying the provider's priority or null if default,

versions - Minimal API version required, should be set to CURRENT_VERSION,

loggerContextFactoryClass - A public exported implementation of LoggerContextFactory or null if getLoggerContextFactory() is also implemented.

Since:

2.9.0

Provider

public Provider(@Nullable Integer priority,
 String versions,
 @Nullable Class<? extends LoggerContextFactory> loggerContextFactoryClass,
 @Nullable Class<? extends ThreadContextMap> threadContextMapClass)

Parameters:

priority - A positive number specifying the provider's priority or null if default,

versions - Minimal API version required, should be set to CURRENT_VERSION,

loggerContextFactoryClass - A public exported implementation of LoggerContextFactory or null if getLoggerContextFactory() is also implemented,

threadContextMapClass - A public exported implementation of ThreadContextMap or null if getThreadContextMapInstance() is implemented.

Since:

2.9.0

Method Details

getVersions

public String getVersions()

Returns the Log4j API versions supported by the implementation.

Returns:

A String containing the Log4j versions supported.

Since:

2.9.0

getPriority

public Integer getPriority()

Gets the priority (natural ordering) of this Provider.

Log4j selects the highest priority provider.

Returns:

the priority of this Provider

getClassName

public @Nullable String getClassName()

Gets the class name of the LoggerContextFactory implementation of this Provider.

Returns:

the class name of a LoggerContextFactory implementation or null if unspecified.

See Also:

• loadLoggerContextFactory()

loadLoggerContextFactory

public @Nullable Class<? extends LoggerContextFactory> loadLoggerContextFactory()

Loads the LoggerContextFactory class specified by this Provider.

Returns:

the LoggerContextFactory implementation class or null if unspecified or a loader error occurred.

Since:

2.0.1

getLoggerContextFactory

public LoggerContextFactory getLoggerContextFactory()

Returns:

The logger context factory to be used by LogManager.

Since:

2.24.0

getThreadContextMap

public @Nullable String getThreadContextMap()

Gets the class name of the ThreadContextMap implementation of this Provider.

Returns:

the class name of a ThreadContextMap implementation

loadThreadContextMap

public @Nullable Class<? extends ThreadContextMap> loadThreadContextMap()

Loads the ThreadContextMap class specified by this Provider.

Returns:

the ThreadContextMap implementation class or null if unspecified or a loading error occurred.

Since:

2.0.1

getThreadContextMapInstance

public ThreadContextMap getThreadContextMapInstance()

Returns:

The thread context map to be used by ThreadContext.

Since:

2.24.0

getUrl

@Deprecated
public @Nullable URL getUrl()

Deprecated.

since 2.24.0, without a replacement.

Gets the URL containing this Provider's Log4j details.

Returns:

the URL corresponding to the Provider META-INF/log4j-provider.properties file or null for a provider class.

toString

public String toString()

Overrides:

toString in class Object

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object