opendap.servers.test

Class dts

java.lang.Object

javax.servlet.GenericServlet

javax.servlet.http.HttpServlet

opendap.servlet.AbstractServlet

opendap.servers.test.dts

All Implemented Interfaces:

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

public class dts
extends AbstractServlet

Purpose:
This is the OPeNDAP Test servlet (dts). It allows the owner of the server to deliver data in ANY valid DDS to a client. This DDS will be filled with invented data if the client requests a DataDDS. This kind of test fixture is useful for evaluating a clients ability to handle the various complexities of the OPeNDAP data types.

Configuration:
The AbstractServlet relies on the javax.servlet.ServletConfig interface (in particular the getInitParameter() method) to retrieve configuration information used by the servlet. InitParameters:

• DebugOn - This controls ouput to the terminal from which the servlet engine was launched. The value is a list of flags that turn on debugging instrumentation in different parts of the code. Values are:
  • showRequest - Show information about the clients request.
  • showResponse - Show information about the servlets response.
  • probeRequest - Show an exhaustive amount of information about the clients request object.


• INFOcache - This is should be set to the directory containing the files used by the ".info" service for the servlet. This directory should contain any dataset specific "over-ride" files (see below), any dataset specific additional information files (see below), and any servlet specific information files(see below).


• DDScache - This is should be set to the directory containing the DDS files for the datasets used by the servlet. Some servlets have been developed that do not use DDS's that are cached on the disk, however the default behaviour is for the servlet to load DDS images from disk.


• DAScache - This is should be set to the directory containing the DAS files for the datasets used by the servlet. Some servlets have been developed that do not use DAS's that are cached on the disk, however the default behaviour is for the servlet to load DAS images from disk.

Here is an example entry from the web.xml file (for tomcat3.3a) for the OPeNDAP Test Server (DTS):

         <servlet>
            <servlet-name>
                dts
            </servlet-name>
 

            <servlet-class>
                opendap.servers.test.dts
            </servlet-class>
 

            <init-param>
                <param-name>DebugOn</param-name>
                <param-value>showRequest showResponse </param-value>
            </init-param>
 

            <init-param>
                <param-name>INFOcache</param-name>
                <param-value>/usr/Java-OPeNDAP/sdds-testsuite/info/</param-value>
            </init-param>
 

            <init-param>
                <param-name>DDScache</param-name>
                <param-value>/usr/Java-OPeNDAP/sdds-testsuite/dds/</param-value>
            </init-param>
 

            <init-param>
                <param-name>DAScache</param-name>
                <param-value>/usr/Java-OPeNDAP/sdds-testsuite/das/</param-value>
            </init-param>
        </servlet>
 

Version:

$Revision: 23881 $

Author:

Nathan David Potter

See Also:

Serialized Form

Field Summary

Fields inherited from class opendap.servlet.AbstractServlet

allowDeflate

Constructor Summary

Constructors

Constructor and Description
dts()

Method Summary

Methods

Modifier and Type	Method and Description
void	doGet(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) ************************************************************************ We override this crucial method from the parent servlet in order to force the client not to cache.
void	doGetASC(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, ReqState rs) ************************************************************************ Default handler for the client's data request.
void	doGetBLOB(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, ReqState rs) ************************************************************************ Default handler for the client's data request.
void	doGetDAP2Data(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, ReqState rs) ************************************************************************ Default handler for the client's data request.
protected GuardedDataset	getDataset(ReqState rs) ************************************************************************ This method must be implemented locally for each OPeNDAP server.
java.lang.String	getServerVersion() ************************************************************************ This method returns a String containing the OPeNDAP Server Version...
void	init() ************************************************************************ Intitializes the servlet.

Methods inherited from class opendap.servlet.AbstractServlet

anyExceptionHandler, badURL, dap2ExceptionHandler, doDebug, doDebugCmd, doGetCatalog, doGetDAS, doGetDDS, doGetDDX, doGetDIR, doGetHELP, doGetHTML, doGetINFO, doGetStatus, doGetSystemProps, doGetVER, getServerName, IOExceptionHandler, parseExceptionHandler, printCatalog, printStatus, probeRequest, sendDODSError

Methods inherited from class javax.servlet.http.HttpServlet

doDelete, doHead, doOptions, doPost, 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

dts

public dts()

Method Detail

init

public void init()
          throws javax.servlet.ServletException

Description copied from class: AbstractServlet

************************************************************************ Intitializes the servlet. Init (at this time) basically sets up the object opendap.util.Debug from the debuggery flags in the servlet InitParameters. The Debug object can be referenced (with impunity) from anywhere in the VM.

Overrides:

init in class AbstractServlet

Throws:

javax.servlet.ServletException

getServerVersion

public java.lang.String getServerVersion()

************************************************************************ This method returns a String containing the OPeNDAP Server Version...

Specified by:

getServerVersion in class AbstractServlet

Returns:

The Server Version String

doGet

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

************************************************************************ We override this crucial method from the parent servlet in order to force the client not to cache. This is achieved by setting the header tag "Last-Modified" to the current date and time.

Overrides:

doGet in class AbstractServlet

Parameters:

request - The client's HttpServletRequest request object.

response - The server's HttpServletResponse response object.

Throws:

java.io.IOException

javax.servlet.ServletException

See Also:

ReqState

doGetDAP2Data

public void doGetDAP2Data(javax.servlet.http.HttpServletRequest request,
                 javax.servlet.http.HttpServletResponse response,
                 ReqState rs)
                   throws java.io.IOException,
                          javax.servlet.ServletException

************************************************************************ Default handler for the client's data request. Requires the getDDS() method implemented by each server localization effort.

Once the DDS has been parsed, the data is read (using the class in the localized server factory etc.), compared to the constraint expression, and then sent to the client.

Overrides:

doGetDAP2Data in class AbstractServlet

Parameters:

request - The client's HttpServletRequest request object.

response - The server's HttpServletResponse response object.

rs - The ReqState of this client request. Contains all kinds of important stuff.

Throws:

java.io.IOException

javax.servlet.ServletException

See Also:

ReqState

doGetASC

public void doGetASC(javax.servlet.http.HttpServletRequest request,
            javax.servlet.http.HttpServletResponse response,
            ReqState rs)
              throws java.lang.Exception

************************************************************************ Default handler for the client's data request. Requires the getDDS() method implemented by each server localization effort.

Once the DDS has been parsed, the data is read (using the class in the localized server factory etc.), compared to the constraint expression, and then sent to the client.

Overrides:

doGetASC in class AbstractServlet

Parameters:

request - The client's HttpServletRequest request object.

response - The server's HttpServletResponse response object.

rs - the decoded Request State

Throws:

java.lang.Exception

doGetBLOB

public void doGetBLOB(javax.servlet.http.HttpServletRequest request,
             javax.servlet.http.HttpServletResponse response,
             ReqState rs)
               throws java.io.IOException,
                      javax.servlet.ServletException

************************************************************************ Default handler for the client's data request. Requires the getDDS() method implemented by each server localization effort.

Once the DDS has been parsed, the data is read (using the class in the localized server factory etc.), compared to the constraint expression, and then sent to the client.

Overrides:

doGetBLOB in class AbstractServlet

Parameters:

request - The client's HttpServletRequest request object.

response - The server's HttpServletResponse response object.

rs - The ReqState of this client request. Contains all kinds of important stuff.

Throws:

java.io.IOException

javax.servlet.ServletException

See Also:

ReqState

This class/method is associated with pre-release version of the DDX API. It is experimental and is subject to (significant) change.

getDataset

protected GuardedDataset getDataset(ReqState rs)
                             throws DAP2Exception,
                                    java.io.IOException,
                                    ParseException

Description copied from class: AbstractServlet

************************************************************************ This method must be implemented locally for each OPeNDAP server. The local implementation of this method is the key piece for connecting any localized data types that are derived from the opendap.dap.Server types back into the running servlet.

This method should do the following:

• Make a new ServerFactory (aka BaseTypeFactory) for the dataset requested.
• Instantiate a ServerDDS using the ServerFactory and populate it (this could be accomplished by just opening a (cached?) DDS in a file and parsing it)
• Return this freshly minted ServerDDS object (to the servlet code where it is used.)

Specified by:

getDataset in class AbstractServlet

Parameters:

rs - The ReqState object for this particular client request.

Returns:

The ServerDDS object all parsed and ready to roll.

Throws:

DAP2Exception

java.io.IOException

ParseException

See Also:

ServerDDS, test_ServerFactory