com.sap.portal.httpconnectivity.transformationservice

Class EPSAXDefaultHandler

java.lang.Object

org.xml.sax.helpers.DefaultHandler

com.sap.portal.httpconnectivity.transformationservice.EPSAXDefaultHandler

All Implemented Interfaces:

IPageContextHolder, ITransformerProperties, Cloneable, ContentHandler, DTDHandler, EntityResolver, ErrorHandler, LexicalHandler

public abstract class EPSAXDefaultHandler
extends org.xml.sax.helpers.DefaultHandler
implements LexicalHandler, ITransformerProperties, IPageContextHolder

An abstract base class for the SAX transformers used in the transformation service.
SAX handlers have access to the result handlers (ContentHandler and LexicalHandler) and to the page context. If the result is an instance of SAXResult, then the resultHandler is available. If the result is an instance of StreamResult, then the writer is available. The writer is a buffer that holds the result.
When implementing the doClone() method make sure that the handler remains thread safe.
The default implementation of DefaultHandler is a simple copy of the source to the result.
The following example shows a simple SAX handler that adds ID to XML nodes. Error handling is removed.

 
public class MyUIDAdderHandler extends EPSAXDefaultHandler
{
                // Map holding the input parameters that this handler exposes.    
    final private static Map mm_inputParameters = new HashMap(10);
    
    // The list of parameters of this transformer
    static
    {
                        // Parameter holding the number of the first ID.
        mm_inputParameters.put("StartUID","Integer");  
    }
 
        private int    m_iUIDCounter;
 
   public MyUIDAdderHandler()
   {
      super();
      m_iUIDCounter = 0;
    }
 
                // Clones the handler.      
    public EPSAXDefaultHandler doClone()
    {           
        return new MyUIDAdderHandler();
    }

    public void startElement(String namespaceURI, String localName, String qName, Attributes attrs)
        throws SAXException
    {
        AttributesImpl newAttrs = new AttributesImpl(attrs);        
        newAttrs.addAttribute("","","UID","integer",Integer.toString(m_iUIDCounter++));
        super.startElement(namespaceURI, localName, qName, newAttrs);
    }

    public void startDocument() throws SAXException
    {
        Integer i = (Integer) m_paremetersMap.get("StartUID");
        if(i!=null)
        {
            m_iUIDCounter = i.intValue(); 
        }
        super.startDocument();
    }

    public Map getInputProperties()
    {       
        return mm_inputParameters;
    }
}
 

Field Summary

Fields

Modifier and Type	Field and Description
protected com.sapportals.htmlb.rendering.IPageContext	m_pageContext The current HTMLB page context.
protected Map	m_paremetersMap The transformer input parameters.
ContentHandler	resultHandler The result content handler.
LexicalHandler	resultLexicalHanlder The result lexical handler.
Writer	writer The writer associated with the result.

Constructor Summary

Constructors

Constructor and Description
EPSAXDefaultHandler() The class constructor.

Method Summary

Modifier and Type	Method and Description
void	characters(char[] ch, int start, int length)
void	clearParameters() Clears the runtime parameters for the handler.
void	comment(char[] ch, int start, int length)
abstract EPSAXDefaultHandler	doClone() Clones the handler.
void	endCDATA()
void	endDocument()
void	endDTD()
void	endElement(String namespaceURI, String localName, String qName)
void	endEntity(String name)
void	endPrefixMapping(String prefix)
void	error(SAXParseException spe)
void	fatalError(SAXParseException spe)
protected String	getNormalizedString(char[] ch, int start, int length) Gets a string from the specified buffer.
com.sapportals.htmlb.rendering.IPageContext	getPageContext() Gets the HTMLB page context.
Object	getParemeter(String name) Gets the parameter value from the runtime parameters.
void	ignorableWhitespace(char[] ch, int start, int length)
void	processingInstruction(String target, String data)
InputSource	resolveEntity(String arg0, String arg1)
void	setPageContext(com.sapportals.htmlb.rendering.IPageContext context) Places the HTMLB page context in the holder.
void	setParemeter(String name, Object value) Sets a runtime parameter.
void	setResult(Result result) Sets the result of the transformation.
void	skippedEntity(String name)
void	startCDATA()
void	startDocument()
void	startDTD(String name, String publicId, String systemId)
void	startElement(String namespaceURI, String localName, String qName, Attributes attrs)
void	startEntity(String name)
void	startPrefixMapping(String prefix, String uri)

Methods inherited from class org.xml.sax.helpers.DefaultHandler

notationDecl, setDocumentLocator, unparsedEntityDecl, warning

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.sap.portal.httpconnectivity.transformationservice.ITransformerProperties

getInputProperties

Field Detail

resultHandler

public ContentHandler resultHandler

The result content handler. The result of the transformer should be written to this handler. This handler is null if it is the last transformer in a pipe.

resultLexicalHanlder

public LexicalHandler resultLexicalHanlder

The result lexical handler. See the JDK documentation for more details.

m_pageContext

protected com.sapportals.htmlb.rendering.IPageContext m_pageContext

The current HTMLB page context. The transformer sets the page context before activating transformation.

m_paremetersMap

protected Map m_paremetersMap

The transformer input parameters.

writer

public Writer writer

The writer associated with the result.

Constructor Detail

EPSAXDefaultHandler

public EPSAXDefaultHandler()

The class constructor.

Method Detail

getPageContext

public com.sapportals.htmlb.rendering.IPageContext getPageContext()

Description copied from interface: IPageContextHolder

Gets the HTMLB page context.

Specified by:

getPageContext in interface IPageContextHolder

Returns:

the page context

setPageContext

public void setPageContext(com.sapportals.htmlb.rendering.IPageContext context)

Description copied from interface: IPageContextHolder

Places the HTMLB page context in the holder.

Specified by:

setPageContext in interface IPageContextHolder

Parameters:

context - the current page context to hold

getParemeter

public Object getParemeter(String name)

Gets the parameter value from the runtime parameters.

Parameters:

name - the name of the parameter

Returns:

the value of the parameter

setParemeter

public void setParemeter(String name,
                         Object value)

Sets a runtime parameter. If the parameter already exists, it is overwritten.

Parameters:

name - the name of the parameter to set

value - the value of the parameter

setResult

public void setResult(Result result)

Sets the result of the transformation. Called by the transformation service before transformation is activated.

Parameters:

result - the result of the transformation

clearParameters

public void clearParameters()

Clears the runtime parameters for the handler. Called each time a transformer is taken from the list of registered transformers.

characters

public void characters(char[] ch,
                       int start,
                       int length)
                throws SAXException

Specified by:

characters in interface ContentHandler

Overrides:

characters in class org.xml.sax.helpers.DefaultHandler

Throws:

SAXException

endDocument

public void endDocument()
                 throws SAXException

Specified by:

endDocument in interface ContentHandler

Overrides:

endDocument in class org.xml.sax.helpers.DefaultHandler

Throws:

SAXException

endElement

public void endElement(String namespaceURI,
                       String localName,
                       String qName)
                throws SAXException

Specified by:

endElement in interface ContentHandler

Overrides:

endElement in class org.xml.sax.helpers.DefaultHandler

Throws:

SAXException

endPrefixMapping

public void endPrefixMapping(String prefix)
                      throws SAXException

Specified by:

endPrefixMapping in interface ContentHandler

Overrides:

endPrefixMapping in class org.xml.sax.helpers.DefaultHandler

Throws:

SAXException

ignorableWhitespace

public void ignorableWhitespace(char[] ch,
                                int start,
                                int length)
                         throws SAXException

Specified by:

ignorableWhitespace in interface ContentHandler

Overrides:

ignorableWhitespace in class org.xml.sax.helpers.DefaultHandler

Throws:

SAXException

processingInstruction

public void processingInstruction(String target,
                                  String data)
                           throws SAXException

Specified by:

processingInstruction in interface ContentHandler

Overrides:

processingInstruction in class org.xml.sax.helpers.DefaultHandler

Throws:

SAXException

skippedEntity

public void skippedEntity(String name)
                   throws SAXException

Specified by:

skippedEntity in interface ContentHandler

Overrides:

skippedEntity in class org.xml.sax.helpers.DefaultHandler

Throws:

SAXException

startDocument

public void startDocument()
                   throws SAXException

Specified by:

startDocument in interface ContentHandler

Overrides:

startDocument in class org.xml.sax.helpers.DefaultHandler

Throws:

SAXException

startElement

public void startElement(String namespaceURI,
                         String localName,
                         String qName,
                         Attributes attrs)
                  throws SAXException

Specified by:

startElement in interface ContentHandler

Overrides:

startElement in class org.xml.sax.helpers.DefaultHandler

Throws:

SAXException

startPrefixMapping

public void startPrefixMapping(String prefix,
                               String uri)
                        throws SAXException

Specified by:

startPrefixMapping in interface ContentHandler

Overrides:

startPrefixMapping in class org.xml.sax.helpers.DefaultHandler

Throws:

SAXException

comment

public void comment(char[] ch,
                    int start,
                    int length)
             throws SAXException

Specified by:

comment in interface LexicalHandler

Throws:

SAXException

endCDATA

public void endCDATA()
              throws SAXException

Specified by:

endCDATA in interface LexicalHandler

Throws:

SAXException

endDTD

public void endDTD()
            throws SAXException

Specified by:

endDTD in interface LexicalHandler

Throws:

SAXException

endEntity

public void endEntity(String name)
               throws SAXException

Specified by:

endEntity in interface LexicalHandler

Throws:

SAXException

startDTD

public void startDTD(String name,
                     String publicId,
                     String systemId)
              throws SAXException

Specified by:

startDTD in interface LexicalHandler

Throws:

SAXException

startEntity

public void startEntity(String name)
                 throws SAXException

Specified by:

startEntity in interface LexicalHandler

Throws:

SAXException

startCDATA

public void startCDATA()
                throws SAXException

Specified by:

startCDATA in interface LexicalHandler

Throws:

SAXException

error

public void error(SAXParseException spe)
           throws SAXException

Specified by:

error in interface ErrorHandler

Overrides:

error in class org.xml.sax.helpers.DefaultHandler

Throws:

SAXException

fatalError

public void fatalError(SAXParseException spe)
                throws SAXException

Specified by:

fatalError in interface ErrorHandler

Overrides:

fatalError in class org.xml.sax.helpers.DefaultHandler

Throws:

SAXException

getNormalizedString

protected String getNormalizedString(char[] ch,
                                     int start,
                                     int length)

Gets a string from the specified buffer. If there is no alpha-numeric value in the buffer, returns an empty string.

Parameters:

ch - the buffer for the characters

start - the starting point in the buffer

length - the number of characters to take from the buffer

Returns:

a normalized string

doClone

public abstract EPSAXDefaultHandler doClone()

Clones the handler.

Returns:

a new instance of the handler

resolveEntity

public InputSource resolveEntity(String arg0,
                                 String arg1)
                          throws SAXException

Specified by:

resolveEntity in interface EntityResolver

Overrides:

resolveEntity in class org.xml.sax.helpers.DefaultHandler

Throws:

SAXException