org.deegree.services.controller
Class OGCFrontController

java.lang.Object
  javax.servlet.GenericServlet
      javax.servlet.http.HttpServlet
          org.deegree.services.controller.OGCFrontController

All Implemented Interfaces:

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

public class OGCFrontController
extends javax.servlet.http.HttpServlet

Servlet that acts as single HTTP communication end point and dispatcher to the OWS instances configured in the DeegreeWorkspace.

Calls to doGet(HttpServletRequest, HttpServletResponse) and doPost(HttpServletRequest, HttpServletResponse) are processed as follows:

The DCP-type of the incoming request is determined. This must be one of the following:

• KVP
• XML
• SOAP (OGC style, the XML request is the child element of the SOAP body)

The responsible OWS instance is determined and one of the following methods is called:

• OWS.doKVP(Map, HttpServletRequest, HttpResponseBuffer, List)
• OWS.doXML(XMLStreamReader, HttpServletRequest, HttpResponseBuffer, List)
• OWS.doSOAP(SOAPEnvelope, HttpServletRequest, HttpResponseBuffer, List, SOAPFactory)

Version:

$Revision: 32084 $, $Date: 2011-10-05 10:46:15 +0200 (Wed, 05 Oct 2011) $

Author:

Rutger Bezema , Markus Schneider , last edited by: $Author: aschmitz $

See Also:

OWS, Serialized Form

Constructor Summary

OGCFrontController()

Method Summary

void	destroy()
protected void	doGet(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) Handles HTTP GET requests.
protected void	doPost(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) Handles HTTP POST requests.
static RequestContext	getContext() Returns the RequestContext associated with the calling thread.
static String	getHttpGetURL() Returns the HTTP URL for communicating with the OGCFrontController over the web (for GET requests).
static String	getHttpPostURL() Returns the HTTP URL for communicating with the OGCFrontController over the web (for POST requests).
static OGCFrontController	getInstance() Returns the only instance of this class.
static WebServicesConfiguration	getServiceConfiguration()
static DeegreeWorkspace	getServiceWorkspace()
void	init(javax.servlet.ServletConfig config)
void	reload() Re-initializes the whole workspace, effectively reloading the whole configuration.
void	reload(String workspaceName) Re-initializes the whole workspace, effectively reloading the whole configuration.
static URL	resolveFileLocation(String location, javax.servlet.ServletContext context) 'Heuristical' method to retrieve the URL for a file referenced from an init-param of a webapp config file which may be: a (absolute) URL a file location a (relative) URL which in turn is resolved using ServletContext.getRealPath

Methods inherited from class javax.servlet.http.HttpServlet

doDelete, doHead, doOptions, 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

OGCFrontController

public OGCFrontController()

Method Detail

getInstance

public static OGCFrontController getInstance()

Returns the only instance of this class.

Returns:

the only instance of this class, never null

Throws:

RuntimeException - if GenericServlet.init() has not been called

getContext

public static RequestContext getContext()

Returns the RequestContext associated with the calling thread.

NOTE: This method will only return a correct result if the calling thread originated in the doGet(HttpServletRequest, HttpServletResponse) or doPost(HttpServletRequest, HttpServletResponse) of this class (or has been spawned as a child thread by such a thread).

Returns:

the RequestContext associated with the calling thread

getServiceWorkspace

public static DeegreeWorkspace getServiceWorkspace()

Returns:

the service workspace

getServiceConfiguration

public static WebServicesConfiguration getServiceConfiguration()

Returns:

the service configuration

getHttpPostURL

public static String getHttpPostURL()

Returns the HTTP URL for communicating with the OGCFrontController over the web (for POST requests).

NOTE: This method will only return a correct result if the calling thread originated in the doGet(HttpServletRequest, HttpServletResponse) or doPost(HttpServletRequest, HttpServletResponse) of this class (or has been spawned as a child thread by such a thread).

Returns:

the HTTP URL (for POST requests)

getHttpGetURL

public static String getHttpGetURL()

Returns the HTTP URL for communicating with the OGCFrontController over the web (for GET requests).

NOTE: This method will only return a correct result if the calling thread originated in the doGet(HttpServletRequest, HttpServletResponse) or doPost(HttpServletRequest, HttpServletResponse) of this class (or has been spawned as a child thread by such a thread).

Returns:

the HTTP URL (for GET requests)

doGet

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

Handles HTTP GET requests.

An HTTP GET request implies that input parameters are specified as key-value pairs. However, at least one OGC service specification allows the sending of XML requests via GET (see WCS 1.0.0 specification, section 6.3.3). In this case, the query string contains no key=value pairs, but the (URL encoded) xml. The encoding ensures that no = char (parameter/value delimiters) occur in the string.

Overrides:

doGet in class javax.servlet.http.HttpServlet

Throws:

javax.servlet.ServletException

IOException

doPost

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

Handles HTTP POST requests.

An HTTP POST request specifies parameters in the request body. OGC service specifications use three different ways to encode the parameters:

• KVP: Parameters are given as key=value pairs which are separated using the & character. This is equivalent to standard HTTP GET requests, except that the parameters are not part of the query string, but the POST body. In this case, the content-type field in the header must be application/x-www-form-urlencoded.
• XML: The POST body contains an XML document. In this case, the content-type field in the header has to be text/xml, but the implementation does not rely on this in order to be more tolerant to clients.
• SOAP: TODO
• Multipart: TODO

Overrides:

doPost in class javax.servlet.http.HttpServlet

Throws:

javax.servlet.ServletException

IOException

init

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

Specified by:

init in interface javax.servlet.Servlet

Overrides:

init in class javax.servlet.GenericServlet

Throws:

javax.servlet.ServletException

reload

public void reload()
            throws IOException,
                   URISyntaxException,
                   javax.servlet.ServletException

Re-initializes the whole workspace, effectively reloading the whole configuration.

Throws:

URISyntaxException

IOException

javax.servlet.ServletException

reload

public void reload(String workspaceName)
            throws IOException,
                   URISyntaxException,
                   javax.servlet.ServletException

Re-initializes the whole workspace, effectively reloading the whole configuration.

Parameters:

workspaceName - if not null, the specified workspace will be started after shutting down the currently running one

Throws:

URISyntaxException

IOException

javax.servlet.ServletException

destroy

public void destroy()

Specified by:

destroy in interface javax.servlet.Servlet

Overrides:

destroy in class javax.servlet.GenericServlet

resolveFileLocation

public static URL resolveFileLocation(String location,
                                      javax.servlet.ServletContext context)
                               throws MalformedURLException

'Heuristical' method to retrieve the URL for a file referenced from an init-param of a webapp config file which may be:

• a (absolute) URL
• a file location
• a (relative) URL which in turn is resolved using ServletContext.getRealPath

Parameters:

location -

context -

Returns:

the full (and whitespace-escaped) URL

Throws:

MalformedURLException