org.nfis.gdas.service
Class GdasServlet

java.lang.Object
  javax.servlet.GenericServlet
      javax.servlet.http.HttpServlet
          org.nfis.util.NfisServlet
              org.nfis.gdas.service.GdasServlet

All Implemented Interfaces:

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

public class GdasServlet
extends org.nfis.util.NfisServlet

Version:

1.0 - Dec 7, 2004 - 4:17:45 PM The GdasServlet implements the GDAS version management described in the GDAS Specification Version 0.9.1, Section 6.2.4. All GDAS requests should be sent to this servlet. The servlet will then forward the request to the correct registered GDAS version implementation.

GDAS implementations are registered with the GdasServlet by configuring the <init-param> <param-name> named 'supportedVersions' element in this web containers web.xml.

First a valid GDAS 'Request' parameter is searched for. If it is not found the request is treated as an XML request. Once the request type and version are determined, requests are forwarded to the proper GDAS implementation.

Author:

emurphy emurphy@pfc.cfs.nrcan.gc.ca

See Also:

Serialized Form

Field Summary

static java.lang.String	APPLICATION_EXCEPTION Error code for unexpected error
static java.lang.String	COMMAND Used by the demo interface
protected static java.lang.String	GET_CAPABILITIES
protected static java.lang.String	GET_DATA
static java.lang.String	INVALID_FORMAT_EXCEPTION_CODE Code when a request cannot be parsed as XML
static java.lang.String	INVALID_PARAMETER_VAUE_ERROR_CODE Error code if there is a missing service, request or version parameter
static java.lang.String	MISSING_PARAMETER_VALUE_ERROR_CODE Error code if a parameter cannot be found
static java.lang.String	TYPE_OF_XML_REQUEST The name of the request attribute that contains the string 'GetCapabilities' or 'GetData'.
protected static java.lang.String	VERSION_PARAM_NAME
static java.lang.String	XML_REQUEST_DOC The name of a GetData XML request stored in the request.

Fields inherited from class org.nfis.util.NfisServlet

DEFAULT_MAX_IN_MEMORY, DEFAULT_MAX_SIZE, FILE_TO_LARGE_ERROR, FILE_UPOAD_ERROR, MAX_IN_MEMORY, MAX_SIZE, NULL_PARAM_ERROR, TEMP_DIRECTORY, UNKNOWN_SIZE_ERROR

Constructor Summary

GdasServlet()

Method Summary

protected void	doGet(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response)
protected void	doPost(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) Examines the request and, depending on its value, calls the appropriate method further process the request.
void	init() Used to initialize variables needed by GDAS, including getting the Versions of GDAS (from the Web.xml) that are available by this service.

Methods inherited from class org.nfis.util.NfisServlet

forwardTo, getCommand, getFileItem, getFileItems, getLanguageFromSession, getParameter, setPropertyFile, writeOutXml

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

Field Detail

COMMAND

public static final java.lang.String COMMAND

Used by the demo interface

See Also:

Constant Field Values

MISSING_PARAMETER_VALUE_ERROR_CODE

public static final java.lang.String MISSING_PARAMETER_VALUE_ERROR_CODE

Error code if a parameter cannot be found

See Also:

Constant Field Values

INVALID_PARAMETER_VAUE_ERROR_CODE

public static final java.lang.String INVALID_PARAMETER_VAUE_ERROR_CODE

Error code if there is a missing service, request or version parameter

See Also:

Constant Field Values

INVALID_FORMAT_EXCEPTION_CODE

public static final java.lang.String INVALID_FORMAT_EXCEPTION_CODE

Code when a request cannot be parsed as XML

See Also:

Constant Field Values

XML_REQUEST_DOC

public static final java.lang.String XML_REQUEST_DOC

The name of a GetData XML request stored in the request.

See Also:

Constant Field Values

TYPE_OF_XML_REQUEST

public static final java.lang.String TYPE_OF_XML_REQUEST

The name of the request attribute that contains the string 'GetCapabilities' or 'GetData'.

See Also:

Constant Field Values

APPLICATION_EXCEPTION

public static final java.lang.String APPLICATION_EXCEPTION

Error code for unexpected error

See Also:

Constant Field Values

GET_DATA

protected static final java.lang.String GET_DATA

See Also:

Constant Field Values

GET_CAPABILITIES

protected static final java.lang.String GET_CAPABILITIES

See Also:

Constant Field Values

VERSION_PARAM_NAME

protected static final java.lang.String VERSION_PARAM_NAME

See Also:

Constant Field Values

Constructor Detail

GdasServlet

public GdasServlet()

Method Detail

init

public void init()
          throws javax.servlet.ServletException

Used to initialize variables needed by GDAS, including getting the Versions of GDAS (from the Web.xml) that are available by this service.

Overrides:

init in class org.nfis.util.NfisServlet

Throws:

javax.servlet.ServletException

doGet

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

Overrides:

doGet in class javax.servlet.http.HttpServlet

Throws:

java.io.IOException

doPost

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

Examines the request and, depending on its value, calls the appropriate method further process the request.

Overrides:

doPost in class javax.servlet.http.HttpServlet

Throws:

java.io.IOException