es.caib.signatura.provider.logging
Class DummyLogFactoryImpl

java.lang.Object
  org.apache.commons.logging.LogFactory
      es.caib.signatura.provider.logging.DummyLogFactoryImpl

public class DummyLogFactoryImpl
extends org.apache.commons.logging.LogFactory

Field Summary

Fields inherited from class org.apache.commons.logging.LogFactory

factories, FACTORY_DEFAULT, FACTORY_PROPERTIES, FACTORY_PROPERTY, SERVICE_ID

Constructor Summary

DummyLogFactoryImpl()

Method Summary

protected static java.lang.Object	createFactory(java.lang.String factoryClass, java.lang.ClassLoader classLoader) Implements the operations described in the javadoc for newFactory.
java.lang.Object	getAttribute(java.lang.String name) Return the configuration attribute with the specified name (if any), or null if there is no such attribute.
java.lang.String[]	getAttributeNames() Return an array containing the names of all currently defined configuration attributes.
static org.apache.commons.logging.LogFactory	getFactory() Construct (if necessary) and return a LogFactory instance, using the following ordered lookup procedure to determine the name of the implementation class to be loaded.
org.apache.commons.logging.Log	getInstance(java.lang.Class clazz) Convenience method to derive a name from the specified class and call getInstance(String) with it.
org.apache.commons.logging.Log	getInstance(java.lang.String name) Construct (if necessary) and return a Log instance, using the factory's current set of configuration attributes.
static org.apache.commons.logging.Log	getLog(java.lang.Class clazz) Convenience method to return a named logger, without the application having to care about factories.
static org.apache.commons.logging.Log	getLog(java.lang.String name) Convenience method to return a named logger, without the application having to care about factories.
protected static org.apache.commons.logging.LogFactory	newFactory(java.lang.String factoryClass, java.lang.ClassLoader classLoader) Method provided for backwards compatibility; see newFactory version that takes 3 parameters.
protected static org.apache.commons.logging.LogFactory	newFactory(java.lang.String factoryClass, java.lang.ClassLoader classLoader, java.lang.ClassLoader contextClassLoader) Return a new instance of the specified LogFactory implementation class, loaded by the specified class loader.
static java.lang.String	objectId(java.lang.Object o) Returns a string that uniquely identifies the specified object, including its class.
void	release() Release any internal references to previously created Log instances returned by this factory.
static void	release(java.lang.ClassLoader classLoader) Release any internal references to previously created LogFactory instances that have been associated with the specified class loader (if any), after calling the instance method release() on each of them.
static void	releaseAll() Release any internal references to previously created LogFactory instances, after calling the instance method release() on each of them.
void	removeAttribute(java.lang.String name) Remove any configuration attribute associated with the specified name.
void	setAttribute(java.lang.String name, java.lang.Object value) Set the configuration attribute with the specified name.

Methods inherited from class org.apache.commons.logging.LogFactory

findClassLoader

Methods inherited from class java.lang.Object

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

Constructor Detail

DummyLogFactoryImpl

public DummyLogFactoryImpl()

Method Detail

getAttribute

public java.lang.Object getAttribute(java.lang.String name)

Return the configuration attribute with the specified name (if any), or null if there is no such attribute.

Specified by:

getAttribute in class org.apache.commons.logging.LogFactory

Parameters:

name - Name of the attribute to return

getAttributeNames

public java.lang.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.

Specified by:

getAttributeNames in class org.apache.commons.logging.LogFactory

getInstance

public org.apache.commons.logging.Log getInstance(java.lang.Class clazz)
                                           throws org.apache.commons.logging.LogConfigurationException

Convenience method to derive a name from the specified class and call getInstance(String) with it.

Specified by:

getInstance in class org.apache.commons.logging.LogFactory

Parameters:

clazz - Class for which a suitable Log name will be derived

Throws:

org.apache.commons.logging.LogConfigurationException - if a suitable Log instance cannot be returned

getInstance

public org.apache.commons.logging.Log getInstance(java.lang.String name)
                                           throws org.apache.commons.logging.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.

Specified by:

getInstance in class org.apache.commons.logging.LogFactory

Parameters:

name - Logical name of the Log instance to be returned (the meaning of this name is only known to the underlying logging implementation that is being wrapped)

Throws:

org.apache.commons.logging.LogConfigurationException - if a suitable Log instance cannot be returned

release

public void release()

Release any internal references to previously created 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.

Specified by:

release in class org.apache.commons.logging.LogFactory

removeAttribute

public void removeAttribute(java.lang.String name)

Remove any configuration attribute associated with the specified name. If there is no such attribute, no action is taken.

Specified by:

removeAttribute in class org.apache.commons.logging.LogFactory

Parameters:

name - Name of the attribute to remove

setAttribute

public void setAttribute(java.lang.String name,
                         java.lang.Object value)

Set the configuration attribute with the specified name. Calling this with a null value is equivalent to calling removeAttribute(name).

Specified by:

setAttribute in class org.apache.commons.logging.LogFactory

Parameters:

name - Name of the attribute to set

value - Value of the attribute to set, or null to remove any setting for this attribute

getFactory

public static org.apache.commons.logging.LogFactory getFactory()
                                                        throws org.apache.commons.logging.LogConfigurationException

Construct (if necessary) and return a LogFactory instance, using the following ordered lookup procedure to determine the name of the implementation class to be loaded.

• The org.apache.commons.logging.LogFactory system property.
• The JDK 1.3 Service Discovery mechanism
• Use the properties file commons-logging.properties file, if found in the class path of this class. The configuration file is in standard java.util.Properties format and contains the fully qualified name of the implementation class with the key being the system property defined above.
• Fall back to a default implementation class (org.apache.commons.logging.impl.LogFactoryImpl).

NOTE - If the properties file method of identifying the LogFactory implementation class is utilized, all of the properties defined in this file will be set as configuration attributes on the corresponding LogFactory instance.

NOTE - In a multithreaded environment it is possible that two different instances will be returned for the same classloader environment.

Throws:

org.apache.commons.logging.LogConfigurationException - if the implementation class is not available or cannot be instantiated.

getLog

public static org.apache.commons.logging.Log getLog(java.lang.Class clazz)
                                             throws org.apache.commons.logging.LogConfigurationException

Convenience method to return a named logger, without the application having to care about factories.

Parameters:

clazz - Class from which a log name will be derived

Throws:

org.apache.commons.logging.LogConfigurationException - if a suitable Log instance cannot be returned

getLog

public static org.apache.commons.logging.Log getLog(java.lang.String name)
                                             throws org.apache.commons.logging.LogConfigurationException

Convenience method to return a named logger, without the application having to care about factories.

Parameters:

name - Logical name of the Log instance to be returned (the meaning of this name is only known to the underlying logging implementation that is being wrapped)

Throws:

org.apache.commons.logging.LogConfigurationException - if a suitable Log instance cannot be returned

release

public static void release(java.lang.ClassLoader classLoader)

Release any internal references to previously created LogFactory instances that have been associated with the specified class loader (if any), after calling the instance method release() on each of them.

Parameters:

classLoader - ClassLoader for which to release the LogFactory

releaseAll

public static void releaseAll()

Release any internal references to previously created LogFactory instances, after calling the instance method release() on each of them. 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.

newFactory

protected static org.apache.commons.logging.LogFactory newFactory(java.lang.String factoryClass,
                                                                  java.lang.ClassLoader classLoader,
                                                                  java.lang.ClassLoader contextClassLoader)
                                                           throws org.apache.commons.logging.LogConfigurationException

Return a new instance of the specified LogFactory implementation class, loaded by the specified class loader. If that fails, try the class loader used to load this (abstract) LogFactory.

ClassLoader conflicts

Note that there can be problems if the specified ClassLoader is not the same as the classloader that loaded this class, ie when loading a concrete LogFactory subclass via a context classloader.

The problem is the same one that can occur when loading a concrete Log subclass via a context classloader.

The problem occurs when code running in the context classloader calls class X which was loaded via a parent classloader, and class X then calls LogFactory.getFactory (either directly or via LogFactory.getLog). Because class X was loaded via the parent, it binds to LogFactory loaded via the parent. When the code in this method finds some LogFactoryYYYY class in the child (context) classloader, and there also happens to be a LogFactory class defined in the child classloader, then LogFactoryYYYY will be bound to LogFactory@childloader. It cannot be cast to LogFactory@parentloader, ie this method cannot return the object as the desired type. Note that it doesn't matter if the LogFactory class in the child classloader is identical to the LogFactory class in the parent classloader, they are not compatible.

The solution taken here is to simply print out an error message when this occurs then throw an exception. The deployer of the application must ensure they remove all occurrences of the LogFactory class from the child classloader in order to resolve the issue. Note that they do not have to move the custom LogFactory subclass; that is ok as long as the only LogFactory class it can find to bind to is in the parent classloader.

Parameters:

factoryClass - Fully qualified name of the LogFactory implementation class

classLoader - ClassLoader from which to load this class

contextClassLoader - is the context that this new factory will manage logging for.

Throws:

org.apache.commons.logging.LogConfigurationException - if a suitable instance cannot be created

Since:

1.1

newFactory

protected static org.apache.commons.logging.LogFactory newFactory(java.lang.String factoryClass,
                                                                  java.lang.ClassLoader classLoader)

Method provided for backwards compatibility; see newFactory version that takes 3 parameters.

This method would only ever be called in some rather odd situation. Note that this method is static, so overriding in a subclass doesn't have any effect unless this method is called from a method in that subclass. However this method only makes sense to use from the getFactory method, and as that is almost always invoked via LogFactory.getFactory, any custom definition in a subclass would be pointless. Only a class with a custom getFactory method, then invoked directly via CustomFactoryImpl.getFactory or similar would ever call this. Anyway, it's here just in case, though the "managed class loader" value output to the diagnostics will not report the correct value.

createFactory

protected static java.lang.Object createFactory(java.lang.String factoryClass,
                                                java.lang.ClassLoader classLoader)

Implements the operations described in the javadoc for newFactory.

Parameters:

factoryClass -

classLoader - used to load the specified factory class. This is expected to be either the TCCL or the classloader which loaded this class. Note that the classloader which loaded this class might be "null" (ie the bootloader) for embedded systems.

Returns:

either a LogFactory object or a LogConfigurationException object.

Since:

1.1

objectId

public static java.lang.String objectId(java.lang.Object o)

Returns a string that uniquely identifies the specified object, including its class.

The returned string is of form "classname@hashcode", ie is the same as the return value of the Object.toString() method, but works even when the specified object's class has overidden the toString method.

Parameters:

o - may be null.

Returns:

a string of form classname@hashcode, or "null" if param o is null.

Since:

1.1