uk.co.weft.domutil
Class JustFetchGenerator

java.lang.Object
  uk.co.weft.domutil.DocumentGeneratorImpl
      uk.co.weft.domutil.JustFetchGenerator

All Implemented Interfaces:

DocumentGenerator

public class JustFetchGenerator

extends DocumentGeneratorImpl

a JustFetchGenerator is not really a generator at all so much as a proxy. It fetches a document from the network in real time and parses it. This makes it easy to apply XSL transforms to arbitrary documents out there in netland but there are some serious words of caution which need to be given.

• This is computationally expensive.
  • Do not use it for locally generated documents - the time penalty will amaze you
  • If at all possible use CachedPage
• You are placing a lot of trust in the quality of the remote provider's XML. If it isn't valid, this will fail.

This class reads just one value from config, source_url, which is, surprisingly, a string representation of the sourc e URL from which the document should be loaded.

Version:

$Revision: 1.6.4.1 $ This revision: $Author: simon $

  $Log: JustFetchGenerator.java,v $
  Revision 1.6.4.1  2005/12/23 10:48:33  simon
  Brute force tidy up after CVS server crash: this time it should work.

  Revision 1.6  2003/09/19 11:05:35  simon
  Feature enhancement: accept source_url from generate time context, over-riding that set in the config.

  Revision 1.5  2003/08/20 09:38:35  simon
  Code cleanup with eclipse; mostly removal of exccessive includes

  Revision 1.4  2002/03/08 10:53:43  simon
  Removed all remaining explicit references to xerces, except as the default
  in DOMStub. All other classes now get parsers as needed from DOMStub.

  Revision 1.3  2002/01/17 15:26:09  simon
  Document generation now working using pure org.w3.dom API.

  Revision 1.2  2001/04/23 10:12:43  simon
  Problem identified in JustFetchGenerator identified that the change to
  init( Config) had not been properly percolated through to DocumentGenerators.
  Fixed.

  Revision 1.1  2000/12/01 12:19:38  simon
  New; Added to CVS.


  

Author:

Simon Brooke (simon@weft.co.uk)

Field Summary

protected java.lang.String

sourceURL

Fields inherited from class uk.co.weft.domutil.DocumentGeneratorImpl

allowXSLFromContext, debug, doctype, dtdPublicId, DTDPUBLICIDCONFIGTOKEN, dtdQualifiedName, DTDQUALIFIEDNAMECONFIGTOKEN, dtdSystemId, DTDSYSTEMIDCONFIGTOKEN, generateDTD, genxml, rootGenerator, rootName, xmlns, xslStylesheetName

Constructor Summary

JustFetchGenerator()

Method Summary

Document	generate(Context context) Fetch the document from the URL and parse it; synchronised because the parser is not thread safe,
void	init(Context config) Initialise this generator with this servlet configuration information

Methods inherited from class uk.co.weft.domutil.DocumentGeneratorImpl

accept, cleanString, destroy, getNamespaceURI, getRootGenerator, getRootGenerator, getTransformURL, init, setRootGenerator

Methods inherited from class java.lang.Object

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

Field Detail

sourceURL

protected java.lang.String sourceURL

Constructor Detail

JustFetchGenerator

public JustFetchGenerator()

Method Detail

generate

public Document generate(Context context)
                  throws GenerationException,
                         DOMException

Fetch the document from the URL and parse it; synchronised because the parser is not thread safe,

Specified by:

generate in interface DocumentGenerator

Overrides:

generate in class DocumentGeneratorImpl

Parameters:

context - the context for this request

Returns:

a document, or null if I can't sensibly generate one in this context

Throws:

GenerationException - if application layer code breaks

DOMException - if anything in Xerces breaks

init

public void init(Context config)
          throws InitialisationException

Initialise this generator with this servlet configuration information

Specified by:

init in interface DocumentGenerator

Overrides:

init in class DocumentGeneratorImpl

Parameters:

config - my initial configuration

Throws:

InitialisationException