org.apache.commons.logging
public abstract class LogFactory extends Object
Factory for creating Log instances, which always delegates to an instance of SLF4JLogFactory.
Field Summary | |
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static String | DIAGNOSTICS_DEST_PROPERTY
The name ( org.apache.commons.logging.diagnostics.dest ) of
the property used to enable internal commons-logging diagnostic output, in
order to get information on what logging implementations are being
discovered, what classloaders they are loaded through, etc.
|
protected static Hashtable | factories
The previously constructed LogFactory instances, keyed by
the ClassLoader with which it was created.
|
static String | FACTORY_DEFAULT
The fully qualified class name of the fallback LogFactory
implementation class to use, if no other can be found.
|
static String | FACTORY_PROPERTIES
The name of the properties file to search for.
|
static String | FACTORY_PROPERTY
The name of the property used to identify the LogFactory implementation
class name.
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static String | HASHTABLE_IMPLEMENTATION_PROPERTY
Setting this system property value allows the |
protected static LogFactory | nullClassLoaderFactory This property is not used but preserved here for compatibility. |
static String | PRIORITY_KEY
The name ( priority ) of the key in the config file used to
specify the priority of that particular config file. |
protected static String | SERVICE_ID
JDK1.3+
'Service Provider' specification.
|
static String | TCCL_KEY
The name ( use_tccl ) of the key in the config file used to
specify whether logging classes should be loaded via the thread context
class loader (TCCL), or not. |
Constructor Summary | |
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protected | LogFactory()
Protected constructor that is not available for public use. |
Method Summary | |
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protected static Object | createFactory(String factoryClass, ClassLoader classLoader)
This method exists to ensure signature compatibility. |
protected static ClassLoader | directGetContextClassLoader()
This method exists to ensure signature compatibility. |
abstract Object | getAttribute(String name)
Return the configuration attribute with the specified name (if any), or
null if there is no such attribute.
|
abstract String[] | getAttributeNames()
Return an array containing the names of all currently defined configuration
attributes. |
protected static ClassLoader | getClassLoader(Class clazz)
This method exists to ensure signature compatibility. |
protected static ClassLoader | getContextClassLoader()
This method exists to ensure signature compatibility. |
static LogFactory | getFactory()
Construct (if necessary) and return a |
abstract Log | getInstance(Class clazz)
Convenience method to derive a name from the specified class and call
getInstance(String) with it.
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abstract Log | getInstance(String name)
Construct (if necessary) and return a |
static Log | getLog(Class clazz)
Convenience method to return a named logger, without the application having
to care about factories.
|
static Log | getLog(String name)
Convenience method to return a named logger, without the application having
to care about factories.
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protected static boolean | isDiagnosticsEnabled()
This method exists to ensure signature compatibility. |
protected static void | logRawDiagnostic(String msg)
This method exists to ensure signature compatibility. |
protected static LogFactory | newFactory(String factoryClass, ClassLoader classLoader, ClassLoader contextClassLoader)
This method exists to ensure signature compatibility. |
protected static LogFactory | newFactory(String factoryClass, ClassLoader classLoader)
This method exists to ensure signature compatibility. |
static String | objectId(Object o)
Returns a string that uniquely identifies the specified object, including
its class.
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abstract void | release()
Release any internal references to previously created Loginstances
returned by this factory. |
static void | release(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. |
abstract void | removeAttribute(String name)
Remove any configuration attribute associated with the specified name. |
abstract void | setAttribute(String name, Object value)
Set the configuration attribute with the specified name. |
org.apache.commons.logging.diagnostics.dest
) of
the property used to enable internal commons-logging diagnostic output, in
order to get information on what logging implementations are being
discovered, what classloaders they are loaded through, etc.
This property is not used but preserved here for compatibility.
LogFactory
instances, keyed by
the ClassLoader
with which it was created.
This property is not used but preserved here for compatibility.
LogFactory
implementation class to use, if no other can be found.
This property is not used but preserved here for compatibility.
This property is not used but preserved here for compatibility.
This property is not used but preserved here for compatibility.
Setting this system property value allows the Hashtable
used
to store classloaders to be substituted by an alternative implementation.
This property is not used but preserved here for compatibility.
This property is not used but preserved here for compatibility.
priority
) of the key in the config file used to
specify the priority of that particular config file. The associated value
is a floating-point number; higher values take priority over lower values.
This property is not used but preserved here for compatibility.
This property is not used but preserved here for compatibility.
use_tccl
) of the key in the config file used to
specify whether logging classes should be loaded via the thread context
class loader (TCCL), or not. By default, the TCCL is used.
This property is not used but preserved here for compatibility.
null
if there is no such attribute.
Parameters: name Name of the attribute to return
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.LogFactory
system
property.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.org.apache.commons.logging.impl.SLF4FLogFactory
).
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.
Throws: LogConfigurationException if the implementation class is not available or cannot be instantiated.
getInstance(String)
with it.
Parameters: clazz Class for which a suitable Log name will be derived
Throws: LogConfigurationException
if a suitable Log
instance cannot be
returned
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.
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: LogConfigurationException
if a suitable Log
instance cannot be
returned
Parameters: clazz Class from which a log name will be derived
Throws: LogConfigurationException
if a suitable Log
instance cannot be
returned
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: LogConfigurationException
if a suitable Log
instance cannot be
returned
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
release()
on each of
them.
Parameters: classLoader ClassLoader for which to release the LogFactory
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.Parameters: name Name of the attribute to remove
null
value is equivalent to calling
removeAttribute(name)
.
Parameters: name
Name of the attribute to set value
Value of the attribute to set, or null
to
remove any setting for this attribute