Concrete subclass of {@link LogFactory} specific to log4j.
*
* @deprecated Per discussion on COMMONS-DEV, the behind-the-scenes use
* of this class as a proxy factory has been removed. For 1.0, you
* can still request it directly if you wish, but it doesn't really
* do anything useful, and will be removed in 1.1.
*
* @author Costin Manolache
*/
public final class Log4jFactory extends LogFactory {
public Log4jFactory() {
super();
}
/**
* The configuration attributes for this {@link LogFactory}.
*/
private Hashtable attributes = new Hashtable();
// previously returned instances, to avoid creation of proxies
private Hashtable instances = new Hashtable();
// --------------------------------------------------------- Public Methods
/**
* Return the configuration attribute with the specified name (if any),
* or null if there is no such attribute.
*
* @param name Name of the attribute to return
*/
public Object getAttribute(String name) {
return (attributes.get(name));
}
/**
* Return an array containing the names of all currently defined
* configuration attributes. If there are no such attributes, a zero
* length array is returned.
*/
public String[] getAttributeNames() {
Vector names = new Vector();
Enumeration keys = attributes.keys();
while (keys.hasMoreElements()) {
names.addElement((String) keys.nextElement());
}
String results[] = new String[names.size()];
for (int i = 0; i < results.length; i++) {
results[i] = (String) names.elementAt(i);
}
return (results);
}
/**
* Convenience method to derive a name from the specified class and
* call getInstance(String) with it.
*
* @param clazz Class for which a suitable Log name will be derived
*
* @exception LogConfigurationException if a suitable Log
* instance cannot be returned
*/
public Log getInstance(Class clazz)
throws LogConfigurationException
{
Log instance = (Log) instances.get(clazz);
if( instance != null )
return instance;
instance=new Log4JLogger( Logger.getLogger( clazz ));
instances.put( clazz, instance );
return instance;
}
public Log getInstance(String name)
throws LogConfigurationException
{
Log instance = (Log) instances.get(name);
if( instance != null )
return instance;
instance=new Log4JLogger( Logger.getLogger( name ));
instances.put( name, instance );
return instance;
}
/**
* Release any internal references to previously created {@link Log}
* instances returned by this factory. This is useful 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 release() {
instances.clear();
// what's the log4j mechanism to cleanup ???
}
/**
* Remove any configuration attribute associated with the specified name.
* If there is no such attribute, no action is taken.
*
* @param name Name of the attribute to remove
*/
public void removeAttribute(String name) {
attributes.remove(name);
}
/**
* Set the configuration attribute with the specified name. Calling
* this with a null value is equivalent to calling
* removeAttribute(name).
*
* @param name Name of the attribute to set
* @param value Value of the attribute to set, or null
* to remove any setting for this attribute
*/
public void setAttribute(String name, Object value) {
if (value == null) {
attributes.remove(name);
} else {
attributes.put(name, value);
}
}
}