Class ChainListener
- java.lang.Object
-
- org.apache.commons.chain.web.ChainListener
-
- All Implemented Interfaces:
java.util.EventListener
,javax.servlet.ServletContextListener
public class ChainListener extends java.lang.Object implements javax.servlet.ServletContextListener
ServletContextListener
that automatically scans chain configuration files in the current web application at startup time, and exposes the result in aCatalog
under a specified servlet context attribute. The following context init parameters are utilized:- org.apache.commons.chain.CONFIG_CLASS_RESOURCE -
comma-delimited list of chain configuration resources to be loaded
via
ClassLoader.getResource()
calls. If not specified, no class loader resources will be loaded. - org.apache.commons.chain.CONFIG_WEB_RESOURCE - comma-delimited list of chain configuration webapp resources to be loaded. If not specified, no web application resources will be loaded.
- org.apache.commons.chain.CONFIG_ATTR -
Name of the servlet context attribute under which the
resulting
Catalog
will be created or updated. If not specified, it is expected that parsed resources will contain<catalog>
elements (which will cause registration of the createdCatalog
s into theCatalogFactory
for this application, and no servet context attribute will be created. NOTE - This parameter is deprecated. - org.apache.commons.chain.RULE_SET -
Fully qualified class name of a Digester
RuleSet
implementation to use for parsing configuration resources (this class must have a public zero-args constructor). If not defined, the standardRuleSet
implementation will be used.
When a web application that has configured this listener is started, it will acquire the
Catalog
under the specified servlet context attribute key, creating a new one if there is none already there. ThisCatalog
will then be populated by scanning configuration resources from the following sources (loaded in this order):- Resources loaded from any
META-INF/chain-config.xml
resource found in a JAR file in/WEB-INF/lib
. - Resources loaded from specified resource paths from the
webapp's class loader (via
ClassLoader.getResource()
). - Resources loaded from specified resource paths in the web application
archive (via
ServetContext.getResource()
).
If no attribute key is specified, on the other hand, parsed configuration resources are expected to contain
<catalog>
elements, and the catalogs will be registered with theCatalogFactory
for this web application.This class requires Servlet 2.3 or later. If you are running on Servlet 2.2 system, consider using
ChainServlet
instead. Note thatChainServlet
uses parameters of the same names, but they are servlet init parameters instead of context init parameters. Because of this, you can use both facilities in the same application, if desired.- Version:
- $Revision: 658426 $ $Date: 2008-05-20 21:55:38 +0100 (Tue, 20 May 2008) $
- Author:
- Craig R. McClanahan, Ted Husted
-
-
Field Summary
Fields Modifier and Type Field Description static java.lang.String
CONFIG_ATTR
The name of the context init parameter containing the name of the servlet context attribute under which our resultingCatalog
will be stored.static java.lang.String
CONFIG_CLASS_RESOURCE
The name of the context init parameter containing a comma-delimited list of class loader resources to be scanned.static java.lang.String
CONFIG_WEB_RESOURCE
The name of the context init parameter containing a comma-delimited list of web applicaton resources to be scanned.static java.lang.String
RULE_SET
The name of the context init parameter containing the fully qualified class name of theRuleSet
implementation for configuring ourConfigParser
.
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Constructor Summary
Constructors Constructor Description ChainListener()
-
Method Summary
All Methods Instance Methods Concrete Methods Deprecated Methods Modifier and Type Method Description void
contextDestroyed(javax.servlet.ServletContextEvent event)
Remove the configuredCatalog
from the servlet context attributes for this web application.void
contextInitialized(javax.servlet.ServletContextEvent event)
Scan the required chain configuration resources, assemble the configured chains into aCatalog
, and expose it as a servlet context attribute under the specified key.private void
parseJarResources(javax.servlet.ServletContext context, ConfigParser parser, org.apache.commons.logging.Log log)
Parse resources found in JAR files in the/WEB-INF/lib
subdirectory (if any).private void
parseJarResources(Catalog catalog, javax.servlet.ServletContext context, ConfigParser parser, org.apache.commons.logging.Log log)
Deprecated.Use the variant that does not take a catalog, on a configuration resource containing "catalog" element(s)private java.lang.String
translate(java.lang.String value)
Translate space character into&pct;20
to avoid problems with paths that contain spaces on some JVMs.
-
-
-
Field Detail
-
CONFIG_ATTR
public static final java.lang.String CONFIG_ATTR
The name of the context init parameter containing the name of the servlet context attribute under which our resulting
Catalog
will be stored.- See Also:
- Constant Field Values
-
CONFIG_CLASS_RESOURCE
public static final java.lang.String CONFIG_CLASS_RESOURCE
The name of the context init parameter containing a comma-delimited list of class loader resources to be scanned.
- See Also:
- Constant Field Values
-
CONFIG_WEB_RESOURCE
public static final java.lang.String CONFIG_WEB_RESOURCE
The name of the context init parameter containing a comma-delimited list of web applicaton resources to be scanned.
- See Also:
- Constant Field Values
-
RULE_SET
public static final java.lang.String RULE_SET
The name of the context init parameter containing the fully qualified class name of the
RuleSet
implementation for configuring ourConfigParser
.- See Also:
- Constant Field Values
-
-
Method Detail
-
contextDestroyed
public void contextDestroyed(javax.servlet.ServletContextEvent event)
Remove the configured
Catalog
from the servlet context attributes for this web application.- Specified by:
contextDestroyed
in interfacejavax.servlet.ServletContextListener
- Parameters:
event
-ServletContextEvent
to be processed
-
contextInitialized
public void contextInitialized(javax.servlet.ServletContextEvent event)
Scan the required chain configuration resources, assemble the configured chains into a
Catalog
, and expose it as a servlet context attribute under the specified key.- Specified by:
contextInitialized
in interfacejavax.servlet.ServletContextListener
- Parameters:
event
-ServletContextEvent
to be processed
-
parseJarResources
private void parseJarResources(javax.servlet.ServletContext context, ConfigParser parser, org.apache.commons.logging.Log log)
Parse resources found in JAR files in the
/WEB-INF/lib
subdirectory (if any).- Parameters:
context
-ServletContext
for this web applicationparser
-ConfigParser
to use for parsing
-
parseJarResources
private void parseJarResources(Catalog catalog, javax.servlet.ServletContext context, ConfigParser parser, org.apache.commons.logging.Log log)
Deprecated.Use the variant that does not take a catalog, on a configuration resource containing "catalog" element(s)Parse resources found in JAR files in the
/WEB-INF/lib
subdirectory (if any).- Parameters:
catalog
-Catalog
we are populatingcontext
-ServletContext
for this web applicationparser
-ConfigParser
to use for parsing
-
translate
private java.lang.String translate(java.lang.String value)
Translate space character into
&pct;20
to avoid problems with paths that contain spaces on some JVMs.- Parameters:
value
- Value to translate
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-