Difference between revisions of "Facade"
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=== Apache Excalibur === | === Apache Excalibur === | ||
| + | <code> | ||
| + | /** | ||
| + | * A facade to the modularized *LoggerManager building system. | ||
| + | * Add methods here to create LoggerManagers to your preference. | ||
| + | * | ||
| + | * @author <a href="mailto:dev@nospamavalon.apache.org">Avalon Development Team</a> | ||
| + | * @version CVS $Revision: 1.3 $ $Date: 2004/03/10 13:54:50 $ | ||
| + | * @since 4.0 | ||
| + | */ | ||
| + | |||
| + | public class Facade | ||
| + | { | ||
| + | /** | ||
| + | * Assemble a new LoggerManager running on top of LogKit | ||
| + | * configured from a configuration file logging to a supplied | ||
| + | * logger as a fallback. | ||
| + | * Use this method as a sample showing how to assemble your | ||
| + | * own LoggerManager running on top of LogKit flavour. | ||
| + | */ | ||
| + | public static LoggerManager createLogKitConfigurable( | ||
| + | final String prefix, final String switchTo ) | ||
| + | { | ||
| + | final org.apache.log.Hierarchy hierarchy = new Hierarchy(); | ||
| + | |||
| + | final LoggerManager bare = new LogKitAdapter( hierarchy ); | ||
| + | final LoggerManager decorated = applyDecorators( bare, prefix, switchTo ); | ||
| + | final LoggerManagerTee tee = new LoggerManagerTee( decorated ); | ||
| + | |||
| + | tee.addTee( new LogKitLoggerHelper( hierarchy ) ); | ||
| + | tee.addTee( new LogKitConfHelper( hierarchy ) ); | ||
| + | tee.makeReadOnly(); | ||
| + | |||
| + | return tee; | ||
| + | } | ||
| + | |||
| + | /** | ||
| + | * Assemble LoggerManager for Log4J system configured | ||
| + | * via a configuration file. All the logging errors | ||
| + | * will go to System.err however. | ||
| + | */ | ||
| + | public static LoggerManager createLog4JConfigurable( | ||
| + | final String prefix, final String switchTo ) | ||
| + | { | ||
| + | final LoggerManager bare = new Log4JConfAdapter(); | ||
| + | final LoggerManager decorated = applyDecorators( bare, prefix, switchTo ); | ||
| + | return decorated; | ||
| + | } | ||
| + | |||
| + | private static LoggerManager applyDecorators( LoggerManager target, | ||
| + | final String prefix, final String switchTo ) | ||
| + | { | ||
| + | if ( switchTo != null ) | ||
| + | { | ||
| + | target = new LogToSelfDecorator( target, switchTo ); | ||
| + | } | ||
| + | if ( prefix != null && prefix.length() > 0 ) | ||
| + | { | ||
| + | target = new PrefixDecorator( target, prefix ); | ||
| + | } | ||
| + | target = new CachingDecorator( target ); | ||
| + | return target; | ||
| + | } | ||
| + | } | ||
| + | </code> | ||
=== Apache Tomcat === | === Apache Tomcat === | ||
Revision as of 15:58, 25 January 2007
Contents
Facade Pattern
The Facade Pattern is used to consolidate numerous complicated objects and function calls in a single interface.
UML Example
Code Examples
Java
C++
C# .NET
VB .NET
Open Source Applications
Apache Excalibur
/**
* A facade to the modularized *LoggerManager building system. * Add methods here to create LoggerManagers to your preference. * * @author <a href="mailto:dev@nospamavalon.apache.org">Avalon Development Team</a> * @version CVS $Revision: 1.3 $ $Date: 2004/03/10 13:54:50 $ * @since 4.0 */
public class Facade {
/**
* Assemble a new LoggerManager running on top of LogKit
* configured from a configuration file logging to a supplied
* logger as a fallback.
* Use this method as a sample showing how to assemble your
* own LoggerManager running on top of LogKit flavour.
*/
public static LoggerManager createLogKitConfigurable(
final String prefix, final String switchTo )
{
final org.apache.log.Hierarchy hierarchy = new Hierarchy();
final LoggerManager bare = new LogKitAdapter( hierarchy );
final LoggerManager decorated = applyDecorators( bare, prefix, switchTo );
final LoggerManagerTee tee = new LoggerManagerTee( decorated );
tee.addTee( new LogKitLoggerHelper( hierarchy ) );
tee.addTee( new LogKitConfHelper( hierarchy ) );
tee.makeReadOnly();
return tee; }
/**
* Assemble LoggerManager for Log4J system configured
* via a configuration file. All the logging errors
* will go to System.err however.
*/
public static LoggerManager createLog4JConfigurable(
final String prefix, final String switchTo )
{
final LoggerManager bare = new Log4JConfAdapter();
final LoggerManager decorated = applyDecorators( bare, prefix, switchTo );
return decorated;
}
private static LoggerManager applyDecorators( LoggerManager target,
final String prefix, final String switchTo )
{
if ( switchTo != null )
{
target = new LogToSelfDecorator( target, switchTo );
}
if ( prefix != null && prefix.length() > 0 )
{
target = new PrefixDecorator( target, prefix );
}
target = new CachingDecorator( target );
return target;
}
}
Apache Tomcat
Links
BTP600
Wikipedia Entry on Facade Pattern
Excalibur Project Site
Excalibur Facade Class Code (via Google! Code Search)
Tomcat Project Site
Tomcat CoyoteRequestFacade Class Code (via Google! Code Search)
Design Pattern in C# and VB.NET
