org.apache.logging.log4j.core.selector

Class JNDIContextSelector

java.lang.Object

org.apache.logging.log4j.core.selector.JNDIContextSelector

All Implemented Interfaces:

ContextSelector, NamedContextSelector

public class JNDIContextSelector
extends Object
implements NamedContextSelector

This class can be used to define a custom logger repository. It makes use of the fact that in J2EE environments, each web-application is guaranteed to have its own JNDI context relative to the java:comp/env context. In EJBs, each enterprise bean (albeit not each application) has its own context relative to the java:comp/env context. An env-entry in a deployment descriptor provides the information to the JNDI context. Once the env-entry is set, a repository selector can query the JNDI application context to look up the value of the entry. The logging context of the web-application will depend on the value the env-entry. The JNDI context which is looked up by this class is java:comp/env/log4j/context-name.

Here is an example of an env-entry:

 <env-entry>
   <description>JNDI logging context name for this app</description>
   <env-entry-name>log4j/context-name</env-entry-name>
   <env-entry-value>aDistinctiveLoggingContextName</env-entry-value>
   <env-entry-type>java.lang.String</env-entry-type>
 </env-entry>
 

If multiple applications use the same logging context name, then they will share the same logging context.

You can also specify the URL for this context's configuration resource. This repository selector (ContextJNDISelector) will use this resource to automatically configure the log4j repository.

 <env-entry>
   <description>URL for configuring log4j context</description>
   <env-entry-name>log4j/configuration-resource</env-entry-name>
   <env-entry-value>urlOfConfigrationResource</env-entry-value>
   <env-entry-type>java.lang.String</env-entry-type>
 </env-entry>
 

It usually good practice for configuration resources of distinct applications to have distinct names. However, if this is not possible Naming

Constructor Summary

Constructors

Constructor and Description
JNDIContextSelector()

Method Summary

Methods

Modifier and Type	Method and Description
LoggerContext	getContext(String fqcn, ClassLoader loader, boolean currentContext) Returns the LoggerContext.
LoggerContext	getContext(String fqcn, ClassLoader loader, boolean currentContext, URI configLocation) Returns the LoggerContext.
List<LoggerContext>	getLoggerContexts() Returns a List of all the available LoggerContexts.
LoggerContext	locateContext(String name, Object externalContext, URI configLocation) Locate the LoggerContext with the specified name.
protected static Object	lookup(Context ctx, String name)
void	removeContext(LoggerContext context) Remove any references to the LoggerContext.
LoggerContext	removeContext(String name) Locate the LoggerContext with the specified name using the default configuration.

Methods inherited from class java.lang.Object

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

Constructor Detail

JNDIContextSelector

public JNDIContextSelector()

Method Detail

getContext

public LoggerContext getContext(String fqcn,
                       ClassLoader loader,
                       boolean currentContext)

Description copied from interface: ContextSelector

Returns the LoggerContext.

Specified by:

getContext in interface ContextSelector

Parameters:

fqcn - The fully qualified class name of the caller.

loader - ClassLoader to use or null.

currentContext - If true returns the current Context, if false returns the Context appropriate for the caller if a more appropriate Context can be determined.

Returns:

The LoggerContext.

getContext

public LoggerContext getContext(String fqcn,
                       ClassLoader loader,
                       boolean currentContext,
                       URI configLocation)

Description copied from interface: ContextSelector

Returns the LoggerContext.

Specified by:

getContext in interface ContextSelector

Parameters:

fqcn - The fully qualified class name of the caller.

loader - ClassLoader to use or null.

currentContext - If true returns the current Context, if false returns the Context appropriate for the caller if a more appropriate Context can be determined.

configLocation - The location of the configuration for the LoggerContext.

Returns:

The LoggerContext.

locateContext

public LoggerContext locateContext(String name,
                          Object externalContext,
                          URI configLocation)

Description copied from interface: NamedContextSelector

Locate the LoggerContext with the specified name.

Specified by:

locateContext in interface NamedContextSelector

Parameters:

name - The LoggerContext name.

externalContext - The external context to associate with the LoggerContext.

configLocation - The location of the configuration.

Returns:

A LoggerContext.

removeContext

public void removeContext(LoggerContext context)

Description copied from interface: ContextSelector

Remove any references to the LoggerContext.

Specified by:

removeContext in interface ContextSelector

Parameters:

context - The context to remove.

removeContext

public LoggerContext removeContext(String name)

Description copied from interface: NamedContextSelector

Locate the LoggerContext with the specified name using the default configuration.

Specified by:

removeContext in interface NamedContextSelector

Parameters:

name - The LoggerContext name.

Returns:

A LoggerContext.

getLoggerContexts

public List<LoggerContext> getLoggerContexts()

Description copied from interface: ContextSelector

Returns a List of all the available LoggerContexts.

Specified by:

getLoggerContexts in interface ContextSelector

Returns:

The List of LoggerContexts.

lookup

protected static Object lookup(Context ctx,
            String name)
                        throws NamingException

Throws:

NamingException