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org.apache.commons.logging.impl
public class: LogFactoryImpl [javadoc | source]
java.lang.Object
   org.apache.commons.logging.LogFactory
      org.apache.commons.logging.impl.LogFactoryImpl

Concrete subclass of LogFactory that implements the following algorithm to dynamically select a logging implementation class to instantiate a wrapper for.

If the selected Log implementation class has a setLogFactory() method that accepts a LogFactory parameter, this method will be called on each newly created instance to identify the associated factory. This makes factory configuration attributes available to the Log instance, if it so desires.

This factory will remember previously created Log instances for the same name, and will return them on repeated requests to the getInstance() method.

Field Summary
public static final  String LOG_PROPERTY    The name (org.apache.commons.logging.Log) of the system property identifying our Log implementation class. 
protected static final  String LOG_PROPERTY_OLD    The deprecated system property used for backwards compatibility with old versions of JCL. 
public static final  String ALLOW_FLAWED_CONTEXT_PROPERTY    The name (org.apache.commons.logging.Log.allowFlawedContext) of the system property which can be set true/false to determine system behaviour when a bad context-classloader is encountered. When set to false, a LogConfigurationException is thrown if LogFactoryImpl is loaded via a child classloader of the TCCL (this should never happen in sane systems). Default behaviour: true (tolerates bad context classloaders) See also method setAttribute. 
public static final  String ALLOW_FLAWED_DISCOVERY_PROPERTY    The name (org.apache.commons.logging.Log.allowFlawedDiscovery) of the system property which can be set true/false to determine system behaviour when a bad logging adapter class is encountered during logging discovery. When set to false, an exception will be thrown and the app will fail to start. When set to true, discovery will continue (though the user might end up with a different logging implementation than they expected). Default behaviour: true (tolerates bad logging adapters) See also method setAttribute. 
public static final  String ALLOW_FLAWED_HIERARCHY_PROPERTY    The name (org.apache.commons.logging.Log.allowFlawedHierarchy) of the system property which can be set true/false to determine system behaviour when a logging adapter class is encountered which has bound to the wrong Log class implementation. When set to false, an exception will be thrown and the app will fail to start. When set to true, discovery will continue (though the user might end up with a different logging implementation than they expected). Default behaviour: true (tolerates bad Log class hierarchy) See also method setAttribute. 
protected  Hashtable attributes    Configuration attributes. 
protected  Hashtable instances    The org.apache.commons.logging.Log instances that have already been created, keyed by logger name. 
protected  Constructor logConstructor    The one-argument constructor of the org.apache.commons.logging.Log implementation class that will be used to create new instances. This value is initialized by getLogConstructor(), and then returned repeatedly. 
protected  Class[] logConstructorSignature    The signature of the Constructor to be used. 
protected  Method logMethod    The one-argument setLogFactory method of the selected org.apache.commons.logging.Log method, if it exists. 
protected  Class[] logMethodSignature    The signature of the setLogFactory method to be used. 
Fields inherited from org.apache.commons.logging.LogFactory:
PRIORITY_KEY,  TCCL_KEY,  FACTORY_PROPERTY,  FACTORY_DEFAULT,  FACTORY_PROPERTIES,  SERVICE_ID,  DIAGNOSTICS_DEST_PROPERTY,  HASHTABLE_IMPLEMENTATION_PROPERTY,  factories,  nullClassLoaderFactory,  class$org$apache$commons$logging$LogFactory,  class$java$lang$Thread
Constructor:
 public LogFactoryImpl() 
Method from org.apache.commons.logging.impl.LogFactoryImpl Summary:
getAttribute,   getAttributeNames,   getClassLoader,   getContextClassLoader,   getInstance,   getInstance,   getLogClassName,   getLogConstructor,   isDiagnosticsEnabled,   isJdk13LumberjackAvailable,   isJdk14Available,   isLog4JAvailable,   logDiagnostic,   newInstance,   release,   removeAttribute,   setAttribute
Methods from org.apache.commons.logging.LogFactory:
access$0,   class$,   createFactory,   directGetContextClassLoader,   getAttribute,   getAttributeNames,   getClassLoader,   getContextClassLoader,   getFactory,   getInstance,   getInstance,   getLog,   getLog,   isDiagnosticsEnabled,   logRawDiagnostic,   newFactory,   newFactory,   objectId,   release,   release,   releaseAll,   removeAttribute,   setAttribute
Methods from java.lang.Object:
clone,   equals,   finalize,   getClass,   hashCode,   notify,   notifyAll,   toString,   wait,   wait,   wait
Method from org.apache.commons.logging.impl.LogFactoryImpl Detail:
 public Object getAttribute(String name) 
    Return the configuration attribute with the specified name (if any), or null if there is no such attribute.
 public String[] getAttributeNames() 
    Return an array containing the names of all currently defined configuration attributes. If there are no such attributes, a zero length array is returned.
 protected static ClassLoader getClassLoader(Class clazz) 
    Workaround for bug in Java1.2; in theory this method is not needed. See LogFactory.getClassLoader.
 protected static ClassLoader getContextClassLoader() throws LogConfigurationException 
    Gets the context classloader. This method is a workaround for a java 1.2 compiler bug.
 public Log getInstance(Class clazz) throws LogConfigurationException 
    Convenience method to derive a name from the specified class and call getInstance(String) with it.
 public Log getInstance(String name) throws LogConfigurationException 

    Construct (if necessary) and return a Log instance, using the factory's current set of configuration attributes.

    NOTE - Depending upon the implementation of the LogFactory you are using, the Log instance you are returned may or may not be local to the current application, and may or may not be returned again on a subsequent call with the same name argument.

 protected String getLogClassName() 
Deprecated! Never - invoked by this class; subclasses should not assume it will be.

    Return the fully qualified Java classname of the Log implementation we will be using.
 protected Constructor getLogConstructor() throws LogConfigurationException 
Deprecated! Never - invoked by this class; subclasses should not assume it will be.

    Return the Constructor that can be called to instantiate new org.apache.commons.logging.Log instances.

    IMPLEMENTATION NOTE - Race conditions caused by calling this method from more than one thread are ignored, because the same Constructor instance will ultimately be derived in all circumstances.

 protected static boolean isDiagnosticsEnabled() 
    Workaround for bug in Java1.2; in theory this method is not needed. See LogFactory.isDiagnosticsEnabled.
 protected boolean isJdk13LumberjackAvailable() 
Deprecated! Never - invoked by this class; subclasses should not assume it will be.

    Is JDK 1.3 with Lumberjack logging available?
 protected boolean isJdk14Available() 
Deprecated! Never - invoked by this class; subclasses should not assume it will be.

    Return true if JDK 1.4 or later logging is available. Also checks that the Throwable class supports getStackTrace(), which is required by Jdk14Logger.

 protected boolean isLog4JAvailable() 
Deprecated! Never - invoked by this class; subclasses should not assume it will be.

    Is a Log4J implementation available?
 protected  void logDiagnostic(String msg) 
    Output a diagnostic message to a user-specified destination (if the user has enabled diagnostic logging).
 protected Log newInstance(String name) throws LogConfigurationException 
 public  void release() 
    Release any internal references to previously created org.apache.commons.logging.Log instances returned by this factory. This is useful in environments like servlet containers, which implement application reloading by throwing away a ClassLoader. Dangling references to objects in that class loader would prevent garbage collection.
 public  void removeAttribute(String name) 
    Remove any configuration attribute associated with the specified name. If there is no such attribute, no action is taken.
 public  void setAttribute(String name,
    Object value) 
    Set the configuration attribute with the specified name. Calling this with a null value is equivalent to calling removeAttribute(name).

    This method can be used to set logging configuration programmatically rather than via system properties. It can also be used in code running within a container (such as a webapp) to configure behaviour on a per-component level instead of globally as system properties would do. To use this method instead of a system property, call

    LogFactory.getFactory().setAttribute(...)
    
    This must be done before the first Log object is created; configuration changes after that point will be ignored.

    This method is also called automatically if LogFactory detects a commons-logging.properties file; every entry in that file is set automatically as an attribute here.