gate.xml
Class XmlDocumentHandler

java.lang.Object
  |
  +--org.xml.sax.helpers.DefaultHandler
        |
        +--gate.xml.XmlDocumentHandler
All Implemented Interfaces:
org.xml.sax.ContentHandler, org.xml.sax.DTDHandler, org.xml.sax.EntityResolver, org.xml.sax.ErrorHandler

public class XmlDocumentHandler
extends org.xml.sax.helpers.DefaultHandler

Implements the behaviour of the XML reader Methods of an object of this class are called by the SAX parser when events will appear. The idea is to parse the XML document and construct Gate annotations objects. This class also will replace the content of the Gate document with a new one containing anly text from the XML document.


Inner Class Summary
(package private)  class XmlDocumentHandler.CustomObject
          The objects belonging to this class are used inside the stack.
 
Field Summary
private  SimpleErrorHandler _seh
          This object inducates what to do when the parser encounts an error
private  AnnotationSet basicAS
          An annotation set used for creating annotation reffering the doc
private  LinkedList colector
          We need a colection to retain all the CustomObjects that will be transformed into annotation over the gate document...
protected  int customObjectsId
          This is used to generate unique Ids for the CustomObjects read
private static boolean DEBUG
          Debug flag
private  Document doc
          A gate document
private  Map element2StringMap
           
private  int elements
          This reports the the number of elements that have beed processed so far
(package private) static int ELEMENTS_RATE
           
private  Map markupElementsMap
           
protected  List myStatusListeners
          Listeners for status report
private  Stack stack
          A stack used to remember elements and to keep the order
private  StringBuffer tmpDocContent
          The content of the XML document, without any tag for internal use
 
Constructor Summary
XmlDocumentHandler(Document aDocument, Map aMarkupElementsMap, Map anElement2StringMap)
          Constructs a XmlDocumentHandler object.
XmlDocumentHandler(Document aDocument, Map aMarkupElementsMap, Map anElement2StringMap, AnnotationSet anAnnotationSet)
          Constructs a XmlDocumentHandler object.
 
Method Summary
 void addStatusListener(StatusListener listener)
          This methos is called when a listener is registered with this class
 void characters(char[] text, int start, int length)
          This method is called when the SAX parser encounts text in the XML doc.
 void comment(String text)
          This method is called when the SAX parser encounts a comment It works only if the XmlDocumentHandler implements a com.sun.parser.LexicalEventListener
 void endCDATA()
          This method is called when the SAX parser encounts the end of a CDATA section.
 void endDocument()
          This method is called when the SAX parser encounts the end of the XML document.
 void endElement(String uri, String qName, String elemName)
          This method is called when the SAX parser encounts the end of an XML element.
 void endParsedEntity(String name, boolean included)
          This method is called when the SAX parser encounts a parsed entity and informs the application if that entity was parsed or not It's working only if the CustomDocumentHandler implements a com.sun.parser.LexicalEventListener
 void error(org.xml.sax.SAXParseException ex)
          Error method.We deal with this exception inside SimpleErrorHandler class
 void fatalError(org.xml.sax.SAXParseException ex)
          FatalError method.
protected  void fireStatusChangedEvent(String text)
          This methos is called whenever we need to inform the listener about an event.
 int getCustomObjectsId()
          Accesor method for the customObjectsId field
private  String getMyLocalName(String aQName)
          This method is a workaround of the java 4 non namespace supporting parser It receives a qualified name and returns its local name.
private  String getMyURI(String aQName)
          Also a workaround for URI identifier.
 void ignorableWhitespace(char[] ch, int start, int length)
          This method is called when the SAX parser encounts white spaces
 void removeStatusListener(StatusListener listener)
          This methos is called when a listener is removed
 void startCDATA()
          This method is called when the SAX parser encounts a start of a CDATA section It works only if the XmlDocumentHandler implements a com.sun.parser.LexicalEventListener
 void startDocument()
          This method is called when the SAX parser encounts the beginning of the XML document.
 void startElement(String uri, String qName, String elemName, org.xml.sax.Attributes atts)
          This method is called when the SAX parser encounts the beginning of an XML element.
 void startParsedEntity(String name)
          This method is called when the SAX parser encounts a parsed Entity It works only if the XmlDocumentHandler implements a com.sun.parser.LexicalEventListener
 void warning(org.xml.sax.SAXParseException ex)
          Warning method comment.
 
Methods inherited from class org.xml.sax.helpers.DefaultHandler
endPrefixMapping, notationDecl, processingInstruction, resolveEntity, setDocumentLocator, skippedEntity, startPrefixMapping, unparsedEntityDecl
 
Methods inherited from class java.lang.Object
, clone, equals, finalize, getClass, hashCode, notify, notifyAll, registerNatives, toString, wait, wait, wait
 

Field Detail

DEBUG

private static final boolean DEBUG
Debug flag

ELEMENTS_RATE

static final int ELEMENTS_RATE

markupElementsMap

private Map markupElementsMap

element2StringMap

private Map element2StringMap

_seh

private SimpleErrorHandler _seh
This object inducates what to do when the parser encounts an error

tmpDocContent

private StringBuffer tmpDocContent
The content of the XML document, without any tag for internal use

stack

private Stack stack
A stack used to remember elements and to keep the order

doc

private Document doc
A gate document

basicAS

private AnnotationSet basicAS
An annotation set used for creating annotation reffering the doc

myStatusListeners

protected List myStatusListeners
Listeners for status report

elements

private int elements
This reports the the number of elements that have beed processed so far

colector

private LinkedList colector
We need a colection to retain all the CustomObjects that will be transformed into annotation over the gate document... the transformation will take place inside onDocumentEnd() method

customObjectsId

protected int customObjectsId
This is used to generate unique Ids for the CustomObjects read
Constructor Detail

XmlDocumentHandler

public XmlDocumentHandler(Document aDocument,
                          Map aMarkupElementsMap,
                          Map anElement2StringMap)
Constructs a XmlDocumentHandler object. The annotationSet set will be the default one taken from the gate document.
Parameters:
aDocument - the Gate document that will be processed.
aMarkupElementsMap - this map contains the elements name that we want to create.
anElement2StringMap - this map contains the strings that will be added to the text contained by the key element.

XmlDocumentHandler

public XmlDocumentHandler(Document aDocument,
                          Map aMarkupElementsMap,
                          Map anElement2StringMap,
                          AnnotationSet anAnnotationSet)
Constructs a XmlDocumentHandler object.
Parameters:
aDocument - the Gate document that will be processed.
aMarkupElementsMap - this map contains the elements name that we want to create.
anElement2StringMap - this map contains the strings that will be added to the text contained by the key element.
anAnnotationSet - is the annotation set that will be filled when the document was processed
Method Detail

startDocument

public void startDocument()
                   throws org.xml.sax.SAXException
This method is called when the SAX parser encounts the beginning of the XML document.
Overrides:
startDocument in class org.xml.sax.helpers.DefaultHandler

endDocument

public void endDocument()
                 throws org.xml.sax.SAXException
This method is called when the SAX parser encounts the end of the XML document. Here we set the content of the gate Document to be the one generated inside this class (tmpDocContent). After that we use the colector to generate all the annotation reffering this new gate document.
Overrides:
endDocument in class org.xml.sax.helpers.DefaultHandler

startElement

public void startElement(String uri,
                         String qName,
                         String elemName,
                         org.xml.sax.Attributes atts)
This method is called when the SAX parser encounts the beginning of an XML element.
Overrides:
startElement in class org.xml.sax.helpers.DefaultHandler

endElement

public void endElement(String uri,
                       String qName,
                       String elemName)
                throws org.xml.sax.SAXException
This method is called when the SAX parser encounts the end of an XML element. Here we extract
Overrides:
endElement in class org.xml.sax.helpers.DefaultHandler

characters

public void characters(char[] text,
                       int start,
                       int length)
                throws org.xml.sax.SAXException
This method is called when the SAX parser encounts text in the XML doc. Here we calculate the end indices for all the elements present inside the stack and update with the new values. For entities, this method is called separatley regardless of the text sourinding the entity.
Overrides:
characters in class org.xml.sax.helpers.DefaultHandler

ignorableWhitespace

public void ignorableWhitespace(char[] ch,
                                int start,
                                int length)
                         throws org.xml.sax.SAXException
This method is called when the SAX parser encounts white spaces
Overrides:
ignorableWhitespace in class org.xml.sax.helpers.DefaultHandler

error

public void error(org.xml.sax.SAXParseException ex)
           throws org.xml.sax.SAXException
Error method.We deal with this exception inside SimpleErrorHandler class
Overrides:
error in class org.xml.sax.helpers.DefaultHandler

fatalError

public void fatalError(org.xml.sax.SAXParseException ex)
                throws org.xml.sax.SAXException
FatalError method.
Overrides:
fatalError in class org.xml.sax.helpers.DefaultHandler

warning

public void warning(org.xml.sax.SAXParseException ex)
             throws org.xml.sax.SAXException
Warning method comment.
Overrides:
warning in class org.xml.sax.helpers.DefaultHandler

comment

public void comment(String text)
             throws org.xml.sax.SAXException
This method is called when the SAX parser encounts a comment It works only if the XmlDocumentHandler implements a com.sun.parser.LexicalEventListener

startCDATA

public void startCDATA()
                throws org.xml.sax.SAXException
This method is called when the SAX parser encounts a start of a CDATA section It works only if the XmlDocumentHandler implements a com.sun.parser.LexicalEventListener

endCDATA

public void endCDATA()
              throws org.xml.sax.SAXException
This method is called when the SAX parser encounts the end of a CDATA section. It works only if the XmlDocumentHandler implements a com.sun.parser.LexicalEventListener

startParsedEntity

public void startParsedEntity(String name)
                       throws org.xml.sax.SAXException
This method is called when the SAX parser encounts a parsed Entity It works only if the XmlDocumentHandler implements a com.sun.parser.LexicalEventListener

endParsedEntity

public void endParsedEntity(String name,
                            boolean included)
                     throws org.xml.sax.SAXException
This method is called when the SAX parser encounts a parsed entity and informs the application if that entity was parsed or not It's working only if the CustomDocumentHandler implements a com.sun.parser.LexicalEventListener

addStatusListener

public void addStatusListener(StatusListener listener)
This methos is called when a listener is registered with this class

removeStatusListener

public void removeStatusListener(StatusListener listener)
This methos is called when a listener is removed

fireStatusChangedEvent

protected void fireStatusChangedEvent(String text)
This methos is called whenever we need to inform the listener about an event.

getMyLocalName

private String getMyLocalName(String aQName)
This method is a workaround of the java 4 non namespace supporting parser It receives a qualified name and returns its local name. For eg. if it receives gate:gateId it will return gateId

getMyURI

private String getMyURI(String aQName)
Also a workaround for URI identifier. If the QName is gate it will return GATE's. Otherwhise it will return the empty string

getCustomObjectsId

public int getCustomObjectsId()
Accesor method for the customObjectsId field