edu.ucsb.adl.middleware
Class CacheControlServlet

java.lang.Object
  |
  +--javax.servlet.GenericServlet
        |
        +--javax.servlet.http.HttpServlet
              |
              +--edu.ucsb.adl.middleware.CacheControlServlet

All Implemented Interfaces:

java.io.Serializable, javax.servlet.Servlet, javax.servlet.ServletConfig

public final class CacheControlServlet

extends javax.servlet.http.HttpServlet

Servlet to manage metadata caches. The servlet is invoked by an HTTP GET request containing three URL-encoded parameters: op, the operation to perform, which must be "empty" (empties a cache), "preload" (starts a background thread to preload a cache), or "stop" (stops a preload thread); collection, the name of a collection; and view, the name of a metadata view that is configured to be cached by the collection. If "*" is specified for the view, all of the collection's caches are operated on.

If the URL of this servlet is S, then an example of a complete URL might be:

S?op=preload&collection=adl_catalog&view=adl:bucket

The successful HTTP status code is 200 (OK). Error status codes include 400 (bad request) and 500 (internal server error).

Version:

$Header: /export/home/gjanee/middleware/edu/ucsb/adl/middleware/RCS/CacheControlServlet.java,v 1.1 2006/06/30 07:29:31 gjanee Exp $

$Log: CacheControlServlet.java,v $ Revision 1.1 2006/06/30 07:29:31 gjanee Initial revision

Author:

Greg Janée
Alexandria Digital Library

See Also:

Serialized Form

Constructor Summary

CacheControlServlet()
Creates a CacheControlServlet.

Method Summary

void	destroy() Frees all resources held by the servlet.
void	doGet(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) Performs the HTTP GET service described above.
void	init(javax.servlet.ServletConfig config) Initializes the servlet.

Methods inherited from class javax.servlet.http.HttpServlet

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

Methods inherited from class javax.servlet.GenericServlet

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

Methods inherited from class java.lang.Object

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

Constructor Detail

CacheControlServlet

public CacheControlServlet()

Creates a CacheControlServlet.

Method Detail

init

public void init(javax.servlet.ServletConfig config)
          throws javax.servlet.ServletException

Initializes the servlet.

Specified by:

init in interface javax.servlet.Servlet

Overrides:

init in class javax.servlet.GenericServlet

Parameters:

config - Must contain the following initialization parameter: middleware_configuration_file, the filename of an ADL middleware configuration file. If the filename is not absolute, it is interpreted relative to the middleware web application directory.

Throws:

javax.servlet.UnavailableException - If the initialization fails.

javax.servlet.ServletException

doGet

public void doGet(javax.servlet.http.HttpServletRequest request,
                  javax.servlet.http.HttpServletResponse response)
           throws java.io.IOException

Performs the HTTP GET service described above.

Overrides:

doGet in class javax.servlet.http.HttpServlet

Parameters:

request - The HTTP request.

response - The HTTP response.

Throws:

java.io.IOException - On any I/O error.

destroy

public void destroy()

Frees all resources held by the servlet.

Specified by:

destroy in interface javax.servlet.Servlet

Overrides:

destroy in class javax.servlet.GenericServlet