Class ChainProcessor

java.lang.Object
javax.servlet.GenericServlet
javax.servlet.http.HttpServlet
org.apache.commons.chain.web.ChainServlet
org.apache.commons.chain.web.servlet.ChainProcessor
All Implemented Interfaces:
Serializable, javax.servlet.Servlet, javax.servlet.ServletConfig
public class ChainProcessor extends ChainServlet

Custom subclass of ChainServlet that also dispatches incoming requests to a configurable Command loaded from the specified Catalog.

In addition to the servlet init parameters supported by ChainServlet, this class supports the following additional parameters:

  • org.apache.commons.chain.CATALOG - Name of the catalog from which to acquire commands to be executed. If not specified, the default catalog for this application will be used.
  • org.apache.commons.chain.COMMAND - Name of the Command (looked up in our configured Catalog used to process all incoming servlet requests. If not specified, defaults to command.

Also, the org.apache.commons.chain.CONFIG_ATTR init parameter is also used to identify the Context attribute under which our configured Catalog will be made available to Commands processing our requests, in addition to its definition of the ServletContext attribute key under which the Catalog is available.

See Also:

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    private String
    attribute
    The name of the context attribute under which our Catalog is stored.
    private String
    catalog
    The name of the Catalog to retrieve from the CatalogFactory for this application, or null to select the default Catalog.
    static final String
    CATALOG
    The name of the servlet init parameter containing the name of the Catalog to use for processing incoming requests.
    static final String
    CATALOG_DEFAULT
    The default request attribute under which we expose the Catalog being used to subordinate Commands.
    private String
    command
    The name of the Command to be executed for each incoming request.
    static final String
    COMMAND
    The name of the servlet init parameter containing the name of the Command (loaded from our configured Catalog to use for processing each incoming request.
    private static final String
    COMMAND_DEFAULT
    The default command name.

    Fields inherited from class ChainServlet

    CONFIG_ATTR, CONFIG_CLASS_RESOURCE, CONFIG_WEB_RESOURCE, RULE_SET

  • Constructor Summary

    Constructors
    Constructor
    Description
    ChainProcessor()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    destroy()
    Clean up as this application is shut down.
    void
    init()
    Cache the name of the command we should execute for each request.
    void
    service(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response)
    Configure a ServletWebContext for the current request, and pass it to the execute() method of the specified Command, loaded from our configured Catalog.

    Methods inherited from class javax.servlet.http.HttpServlet

    doDelete, doGet, doHead, doOptions, doPost, doPut, doTrace, getLastModified, service

    Methods inherited from class javax.servlet.GenericServlet

    getInitParameter, getInitParameterNames, getServletConfig, getServletContext, getServletInfo, getServletName, init, log, log

    Methods inherited from class Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Field Details

    • CATALOG

      public static final String CATALOG

      The name of the servlet init parameter containing the name of the Catalog to use for processing incoming requests.

      See Also:

    • CATALOG_DEFAULT

      public static final String CATALOG_DEFAULT

      The default request attribute under which we expose the Catalog being used to subordinate Commands.

      See Also:

    • COMMAND

      public static final String COMMAND

      The name of the servlet init parameter containing the name of the Command (loaded from our configured Catalog to use for processing each incoming request.

      See Also:

    • COMMAND_DEFAULT

      private static final String COMMAND_DEFAULT

      The default command name.

      See Also:

    • attribute

      private String attribute

      The name of the context attribute under which our Catalog is stored. This value is also used as the name of the context attribute under which the catalog is exposed to commands. If not specified, we will look up commands in the appropriate Catalog retrieved from our CatalogFactory.

    • catalog

      private String catalog

      The name of the Catalog to retrieve from the CatalogFactory for this application, or null to select the default Catalog.

    • command

      private String command

      The name of the Command to be executed for each incoming request.

  • Constructor Details

    • ChainProcessor

      public ChainProcessor()

  • Method Details

    • destroy

      public void destroy()

      Clean up as this application is shut down.

      Specified by:
      destroy in interface javax.servlet.Servlet
      Overrides:
      destroy in class ChainServlet

    • init

      public void init() throws javax.servlet.ServletException

      Cache the name of the command we should execute for each request.

      Overrides:
      init in class ChainServlet
      Throws:
      javax.servlet.ServletException - if an initialization error occurs

    • service

      public void service(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) throws IOException, javax.servlet.ServletException

      Configure a ServletWebContext for the current request, and pass it to the execute() method of the specified Command, loaded from our configured Catalog.

      Overrides:
      service in class ChainServlet
      Parameters:
      request - The request we are processing
      response - The response we are creating
      Throws:
      IOException - if an input/output error occurs
      javax.servlet.ServletException - if a servlet exception occurs