gov.nasa.pds.dsview.servlets

Class SwitchingQueryServlet

java.lang.Object

javax.servlet.GenericServlet

javax.servlet.http.HttpServlet

gov.nasa.pds.dsview.servlets.SwitchingQueryServlet

All Implemented Interfaces:

Serializable, javax.servlet.Servlet, javax.servlet.ServletConfig

public class SwitchingQueryServlet
extends javax.servlet.http.HttpServlet

The switching servlet dispatches an incoming request to a specific web resource depending on the reslcass parameter. At initialization time, the servlet reads each initialization parameter and treats it as a resclass-to-web resource (by path) mapping. It saves each mapping. Then, for any GET or POST request, it looks for the resclass parameter and finds the corresponding web resource path. It then fowards the request to that resource, but without the resclass parameter.

If the resclass parameter is missing or is empty, the result is a 400 (bad request). If the web resource is missing from the web server, the result is a 404 (not found).

Version:

$Revision: 11907 $

Author:

Kelly

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
SwitchingQueryServlet()

Method Summary

Methods

Modifier and Type	Method and Description
void	doGet(javax.servlet.http.HttpServletRequest req, javax.servlet.http.HttpServletResponse res)
void	doIt(javax.servlet.http.HttpServletRequest req, javax.servlet.http.HttpServletResponse res) Examine the resclass parameter and forward to the mapped web context resource.
void	doPost(javax.servlet.http.HttpServletRequest req, javax.servlet.http.HttpServletResponse res)
void	init(javax.servlet.ServletConfig config) Initialize the resource mappings.

Methods inherited from class javax.servlet.http.HttpServlet

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

Methods inherited from class javax.servlet.GenericServlet

destroy, 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

SwitchingQueryServlet

public SwitchingQueryServlet()

Method Detail

init

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

Initialize the resource mappings. Each init parameter maps a resclass to a web context resource.

Specified by:

init in interface javax.servlet.Servlet

Overrides:

init in class javax.servlet.GenericServlet

Parameters:

config - a ServletConfig value.

Throws:

javax.servlet.ServletException - if an error occurs.

doGet

public void doGet(javax.servlet.http.HttpServletRequest req,
         javax.servlet.http.HttpServletResponse res)
           throws javax.servlet.ServletException,
                  IOException

Overrides:

doGet in class javax.servlet.http.HttpServlet

Throws:

javax.servlet.ServletException

IOException

doPost

public void doPost(javax.servlet.http.HttpServletRequest req,
          javax.servlet.http.HttpServletResponse res)
            throws javax.servlet.ServletException,
                   IOException

Overrides:

doPost in class javax.servlet.http.HttpServlet

Throws:

javax.servlet.ServletException

IOException

doIt

public void doIt(javax.servlet.http.HttpServletRequest req,
        javax.servlet.http.HttpServletResponse res)
          throws javax.servlet.ServletException,
                 IOException

Examine the resclass parameter and forward to the mapped web context resource.

Parameters:

req - a HttpServletRequest value.

res - a HttpServletResponse value.

Throws:

javax.servlet.ServletException - if an error occurs.

IOException - if an error occurs.