Class ProviderUtil

java.lang.Object

org.apache.logging.log4j.util.ProviderUtil

@InternalApi
public final class ProviderUtil
extends Object

Consider this class private.

Utility class for Log4j Providers. When integrating with an application container framework, any Log4j Providers not accessible through standard classpath scanning should loadProvider(java.net.URL, ClassLoader) a classpath accordingly.

Field Summary

Fields

Modifier and Type	Field	Description
private static final String[]	COMPATIBLE_API_VERSIONS
private static final Logger	LOGGER
private static Provider	PROVIDER
(package private) static final String	PROVIDER_RESOURCE	Resource name for a Log4j 2 provider properties file.
(package private) static final Collection<Provider>	PROVIDERS	Loaded providers.
(package private) static final Lock	STARTUP_LOCK	Guards the ProviderUtil singleton instance from lazy initialization.

Constructor Summary

Constructors

Modifier	Constructor	Description
private	ProviderUtil()

Method Summary

Modifier and Type	Method	Description
(package private) static void	addProvider(Provider provider)
static ClassLoader	findClassLoader()
static Provider	getProvider()
static Iterable<Provider>	getProviders()
static boolean	hasProviders()
(package private) static void	lazyInit()	Lazily initializes the ProviderUtil singleton.
(package private) static void	loadProvider(URL url, ClassLoader cl)	Loads an individual Provider implementation.
(package private) static void	loadProviders(Enumeration<URL> urls, ClassLoader cl)	Deprecated. Use loadProvider(java.net.URL, ClassLoader) instead.
(package private) static Provider	selectProvider(PropertiesUtil properties, Collection<Provider> providers, Logger statusLogger)	Used to test the public getProvider() method.
private static boolean	validVersion(String version)

Methods inherited from class Object

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

Field Details

PROVIDER_RESOURCE

static final String PROVIDER_RESOURCE

Resource name for a Log4j 2 provider properties file.

See Also:

• Constant Field Values

PROVIDERS

static final Collection<Provider> PROVIDERS

Loaded providers.

STARTUP_LOCK

static final Lock STARTUP_LOCK

Guards the ProviderUtil singleton instance from lazy initialization.

This is primarily used for OSGi support. It allows the OSGi Activator to pause the startup and wait for a Provider to be installed. See LOG4J2-373.

COMPATIBLE_API_VERSIONS

private static final String[] COMPATIBLE_API_VERSIONS

LOGGER

private static final Logger LOGGER

PROVIDER

private static volatile Provider PROVIDER

Constructor Details

ProviderUtil

private ProviderUtil()

Method Details

addProvider

static void addProvider(Provider provider)

loadProvider

static void loadProvider(URL url,
 ClassLoader cl)

Loads an individual Provider implementation. This method is really only useful for the OSGi bundle activator and this class itself.

Parameters:

url - the URL to the provider properties file

cl - the ClassLoader to load the provider classes with

loadProviders

@Deprecated
static void loadProviders(Enumeration<URL> urls,
 ClassLoader cl)

Deprecated.

Use loadProvider(java.net.URL, ClassLoader) instead. Will be removed in 3.0.

getProvider

public static Provider getProvider()

Since:

2.24.0

getProviders

public static Iterable<Provider> getProviders()

hasProviders

public static boolean hasProviders()

lazyInit

static void lazyInit()

Lazily initializes the ProviderUtil singleton.

Note that the following initial call to ProviderUtil may block until a Provider has been installed when running in an OSGi environment.

selectProvider

static Provider selectProvider(PropertiesUtil properties,
 Collection<Provider> providers,
 Logger statusLogger)

Used to test the public getProvider() method.

findClassLoader

public static ClassLoader findClassLoader()

validVersion

private static boolean validVersion(String version)