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org.apache.commons.chain.web
public class: ChainServlet [javadoc | source]
java.lang.Object
   javax.servlet.GenericServlet
      javax.servlet.http.HttpServlet
         org.apache.commons.chain.web.ChainServlet

All Implemented Interfaces:
    Serializable, Servlet, ServletConfig

Direct Known Subclasses:
    ChainProcessor

Servlet that automatically scans chain configuration files in the current web application at startup time, and exposes the result in a Catalog under a specified servlet context attribute. The following servlet init parameters are utilized:

When a web application that has configured this servlet is started, it will acquire the Catalog under the specified servlet context attribute key, creating a new one if there is none already there. This Catalog will then be populated by scanning configuration resources from the following sources (loaded in this order):

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 the CatalogFactory for this web application.

This class runs on Servlet 2.2 or later. If you are running on a Servlet 2.3 or later system, you should also consider using ChainListener to initialize your Catalog . Note that ChainListener uses parameters of the same names, but they are context init parameters instead of servlet init parameters. Because of this, you can use both facilities in the same application, if desired.

Field Summary
public static final  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.

 
public static final  String CONFIG_CLASS_RESOURCE   

The name of the context init parameter containing a comma-delimited list of class loader resources to be scanned.

 
public static final  String CONFIG_WEB_RESOURCE   

The name of the context init parameter containing a comma-delimited list of web applicaton resources to be scanned.

 
public static final  String RULE_SET   

The name of the context init parameter containing the fully qualified class name of the RuleSet implementation for configuring our ConfigParser .

 
Method from org.apache.commons.chain.web.ChainServlet Summary:
destroy,   init,   service
Methods from javax.servlet.http.HttpServlet:
service
Methods from javax.servlet.GenericServlet:
destroy,   getInitParameter,   getInitParameterNames,   getServletConfig,   getServletContext,   getServletInfo,   getServletName,   init,   init,   log,   log,   service
Methods from java.lang.Object:
equals,   getClass,   hashCode,   notify,   notifyAll,   toString,   wait,   wait,   wait
Method from org.apache.commons.chain.web.ChainServlet Detail:
 public  void destroy() 

    Clean up after ourselves as this application shuts down.

 public  void init() throws ServletException 

    Create (if necessary) and configure a Catalog from the servlet init parameters that have been specified.

 public  void service(HttpServletRequest request,
    HttpServletResponse response) throws IOException, ServletException 

    Does nothing; this servlet's only purpose is to initialize a Chain and store it in the servlet context.