Package thredds.server.opendap

Class OpendapServlet

java.lang.Object

javax.servlet.GenericServlet

javax.servlet.http.HttpServlet

thredds.server.opendap.servlet.AbstractServlet

thredds.server.opendap.OpendapServlet

All Implemented Interfaces:

Serializable, javax.servlet.Servlet, javax.servlet.ServletConfig, org.springframework.beans.factory.InitializingBean

@Controller
@RequestMapping("/dods")
public class OpendapServlet
extends AbstractServlet
implements org.springframework.beans.factory.InitializingBean

THREDDS opendap server.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
static org.slf4j.Logger	log

Constructor Summary

Constructors

Constructor	Description
OpendapServlet()

Method Summary

Modifier and Type	Method	Description
void	afterPropertiesSet()
void	dap2ExceptionHandler(opendap.dap.DAP2Exception de, ReqState rs)
void	doGet(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response)	Handles incoming requests from clients.
void	doGetASC(ReqState rs)	Default handler for OPeNDAP ascii data requests.
void	doGetBLOB(ReqState rs)	Default handler for the client's data request.
void	doGetDAP2Data(ReqState rs)	Default handler for the client's data request.
void	doGetDAS(ReqState rs)	Default handler for the client's DAS request.
void	doGetDDS(ReqState rs)	Default handler for the client's DDS request.
void	doGetDDX(ReqState rs)	Default handler for the client's DDS request.
void	doGetDIR(ReqState rs)	Default handler for the client's directory request.
void	doGetHELP(ReqState rs)	Default handler for the client's help request.
void	doGetHTML(ReqState rs)	Default handler for OPeNDAP .html requests.
void	doGetINFO(ReqState rs)	Default handler for OPeNDAP info requests.
void	doGetVER(ReqState rs)	Default handler for the client's version request.
protected GuardedDataset	getDataset(ReqState preq)	This method must be implemented locally for each OPeNDAP server.
protected long	getLastModified(javax.servlet.http.HttpServletRequest req)
protected ReqState	getRequestState(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response)
String	getServerName()	In this (default) implementation of the getServerName() method we just get the name of the servlet and pass it back.
String	getServerVersion()	This function must be implemented locally for each OPeNDAP server.
void	parseExceptionHandler(opendap.dap.parsers.ParseException pe, javax.servlet.http.HttpServletResponse response)	Turns a ParseException into a OPeNDAP DAP2 error and sends it to the client.
protected void	printBadURLPage(PrintWriter pw)	Prints the Bad URL Page page to the passed PrintWriter

Methods inherited from class thredds.server.opendap.servlet.AbstractServlet

anyExceptionHandler, badURL, dap2ExceptionHandler, doDebug, doDebugCmd, doGetCatalog, doGetStatus, doGetSystemProps, IOExceptionHandler, parseConstraint, printCatalog, printStatus, printThrowable, probeRequest, sendDODSError, setLog

Methods inherited from class javax.servlet.http.HttpServlet

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

Methods inherited from class javax.servlet.GenericServlet

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

Methods inherited from class java.lang.Object

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

Field Detail

log

public static org.slf4j.Logger log

Constructor Detail

OpendapServlet

public OpendapServlet()

Method Detail

afterPropertiesSet

public void afterPropertiesSet()

Specified by:

afterPropertiesSet in interface org.springframework.beans.factory.InitializingBean

getServerVersion

public String getServerVersion()

Description copied from class: AbstractServlet

This function must be implemented locally for each OPeNDAP server. It should return a String containing the OPeNDAP Server Version...

Specified by:

getServerVersion in class AbstractServlet

Returns:

The Server Version String

getLastModified

protected long getLastModified(javax.servlet.http.HttpServletRequest req)

Overrides:

getLastModified in class javax.servlet.http.HttpServlet

doGet

@RequestMapping(value="**",
                method=GET)
public void doGet(javax.servlet.http.HttpServletRequest request,
                  javax.servlet.http.HttpServletResponse response)

Description copied from class: AbstractServlet

Handles incoming requests from clients. Parses the request and determines what kind of OPeNDAP response the client is requesting. If the request is understood, then the appropriate handler method is called, otherwise an error is returned to the client.

This method is the entry point for AbstractServlet.

Overrides:

doGet in class AbstractServlet

Parameters:

request - The client's HttpServletRequest request object.

response - The server's HttpServletResponse response object.

See Also:

ReqState

doGetASC

public void doGetASC(ReqState rs)
              throws Exception

Description copied from class: AbstractServlet

Default handler for OPeNDAP ascii data requests. Returns the request data as a comma delimited ascii file. Note that this means that the more complex OPeNDAP structures such as Grids get flattened... Modified 2/8/07 jcaron to not make a DConnect2 call to itself

Overrides:

doGetASC in class AbstractServlet

Parameters:

rs - the decoded Request State

Throws:

Exception

doGetDAS

public void doGetDAS(ReqState rs)
              throws Exception

Description copied from class: AbstractServlet

Default handler for the client's DAS request. Operates on the assumption that the DAS information is cached on a disk local to the server. If you don't like that, then you better override it in your server :)

Once the DAS has been parsed it is sent to the requesting client.

Overrides:

doGetDAS in class AbstractServlet

Parameters:

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

Throws:

Exception

See Also:

ReqState

doGetDDS

public void doGetDDS(ReqState rs)
              throws Exception

Description copied from class: AbstractServlet

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

Once the DDS has been parsed and constrained it is sent to the requesting client.

Overrides:

doGetDDS in class AbstractServlet

Parameters:

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

Throws:

Exception

See Also:

ReqState

doGetDDX

public void doGetDDX(ReqState rs)
              throws Exception

Description copied from class: AbstractServlet

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

Once the DDS has been parsed and constrained it is sent to the requesting client.

Overrides:

doGetDDX in class AbstractServlet

Parameters:

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

Throws:

Exception

See Also:

ReqState

doGetBLOB

public void doGetBLOB(ReqState rs)
               throws Exception

Description copied from class: AbstractServlet

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:

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

Throws:

Exception

See Also:

ReqState

doGetDAP2Data

public void doGetDAP2Data(ReqState rs)
                   throws Exception

Description copied from class: AbstractServlet

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:

rs - The ReqState of this client request.

Throws:

Exception

doGetVER

public void doGetVER(ReqState rs)
              throws Exception

Description copied from class: AbstractServlet

Default handler for the client's version request.

Returns a plain text document with server version and OPeNDAP core version #'s

Overrides:

doGetVER in class AbstractServlet

Parameters:

rs - The client's ReqState

Throws:

Exception

doGetHELP

public void doGetHELP(ReqState rs)
               throws Exception

Description copied from class: AbstractServlet

Default handler for the client's help request. Returns an html page of help info for the server

Overrides:

doGetHELP in class AbstractServlet

Parameters:

rs - The client's ReqState

Throws:

Exception

doGetDIR

public void doGetDIR(ReqState rs)
              throws Exception

Description copied from class: AbstractServlet

Default handler for the client's directory request.

Returns an html document to the client showing (a possibly pseudo) listing of the datasets available on the server in a directory listing format.

The bulk of this code resides in the class opendap.servlet.GetDirHandler and documentation may be found there.

Overrides:

doGetDIR in class AbstractServlet

Parameters:

rs - The client's ReqState

Throws:

Exception

See Also:

GetDirHandler

doGetINFO

public void doGetINFO(ReqState rs)
               throws Exception

Description copied from class: AbstractServlet

Default handler for OPeNDAP info requests. Returns an HTML document describing the contents of the servers datasets.

Overrides:

doGetINFO in class AbstractServlet

Parameters:

rs - The client's ReqState

Throws:

Exception

See Also:

GetInfoHandler

doGetHTML

public void doGetHTML(ReqState rs)
               throws Exception

Description copied from class: AbstractServlet

Default handler for OPeNDAP .html requests. Returns the OPeNDAP Web Interface (aka The Interface From Hell) to the client.

The bulk of this code resides in the class opendap.servlet.GetHTMLInterfaceHandler and documentation may be found there.

Overrides:

doGetHTML in class AbstractServlet

Parameters:

rs - The client's ReqState

Throws:

Exception

See Also:

GetHTMLInterfaceHandler

getServerName

public String getServerName()

Description copied from class: AbstractServlet

In this (default) implementation of the getServerName() method we just get the name of the servlet and pass it back. If something different is required, override this method when implementing the getDDS() and getServerVersion() methods.

This is typically used by the getINFO() method to figure out if there is information specific to this server residing in the info directory that needs to be returned to the client as part of the .info rs.getResponse().

Overrides:

getServerName in class AbstractServlet

Returns:

A string containing the name of the servlet class that is running.

printBadURLPage

protected void printBadURLPage(PrintWriter pw)

Prints the Bad URL Page page to the passed PrintWriter

Overrides:

printBadURLPage in class AbstractServlet

Parameters:

pw - PrintWriter stream to which to dump the bad URL page.

getRequestState

protected ReqState getRequestState(javax.servlet.http.HttpServletRequest request,
                                   javax.servlet.http.HttpServletResponse response)

Overrides:

getRequestState in class AbstractServlet

Returns:

the request state

getDataset

protected GuardedDataset getDataset(ReqState preq)
                             throws Exception

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.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:

preq - The ReqState object for this particular client request.

Returns:

A GuardedDataset object cintaininb the parsed DAS and DDS.

Throws:

Exception

parseExceptionHandler

public void parseExceptionHandler(opendap.dap.parsers.ParseException pe,
                                  javax.servlet.http.HttpServletResponse response)

Description copied from class: AbstractServlet

Turns a ParseException into a OPeNDAP DAP2 error and sends it to the client.

Overrides:

parseExceptionHandler in class AbstractServlet

Parameters:

pe - The ParseException that caused the problem.

response - The HttpServletResponse for the client.

dap2ExceptionHandler

public void dap2ExceptionHandler(opendap.dap.DAP2Exception de,
                                 ReqState rs)