- * This module, both source code and documentation, is in the - * Public Domain, and comes with NO WARRANTY. - *- * - *
This class is designed to sit between an {@link org.xml.sax.XMLReader - * XMLReader} and the client application's event handlers. By default, it - * does nothing but pass requests up to the reader and events - * on to the handlers unmodified, but subclasses can override - * specific methods to modify the event stream or the configuration - * requests as they pass through.
- * - * @since SAX 2.0 - * @author David Megginson, - * sax@megginson.com - * @version 2.0 - * @see org.xml.sax.XMLFilter - * @see org.xml.sax.XMLReader - * @see org.xml.sax.EntityResolver - * @see org.xml.sax.DTDHandler - * @see org.xml.sax.ContentHandler - * @see org.xml.sax.ErrorHandler - */ -public class XMLFilterImpl - implements XMLFilter, EntityResolver, DTDHandler, ContentHandler, ErrorHandler -{ - - - //////////////////////////////////////////////////////////////////// - // Constructors. - //////////////////////////////////////////////////////////////////// - - - /** - * Construct an empty XML filter, with no parent. - * - *This filter will have no parent: you must assign a parent - * before you start a parse or do any configuration with - * setFeature or setProperty.
- * - * @see org.xml.sax.XMLReader#setFeature - * @see org.xml.sax.XMLReader#setProperty - */ - public XMLFilterImpl () - { - super(); - } - - - /** - * Construct an XML filter with the specified parent. - * - * @see #setParent - * @see #getParent - */ - public XMLFilterImpl (XMLReader parent) - { - super(); - setParent(parent); - } - - - - //////////////////////////////////////////////////////////////////// - // Implementation of org.xml.sax.XMLFilter. - //////////////////////////////////////////////////////////////////// - - - /** - * Set the parent reader. - * - *This is the {@link org.xml.sax.XMLReader XMLReader} from which - * this filter will obtain its events and to which it will pass its - * configuration requests. The parent may itself be another filter.
- * - *If there is no parent reader set, any attempt to parse - * or to set or get a feature or property will fail.
- * - * @param parent The parent XML reader. - * @exception java.lang.NullPointerException If the parent is null. - * @see #getParent - */ - public void setParent (XMLReader parent) - { - if (parent == null) { - throw new NullPointerException("Null parent"); - } - this.parent = parent; - } - - - /** - * Get the parent reader. - * - * @return The parent XML reader, or null if none is set. - * @see #setParent - */ - public XMLReader getParent () - { - return parent; - } - - - - //////////////////////////////////////////////////////////////////// - // Implementation of org.xml.sax.XMLReader. - //////////////////////////////////////////////////////////////////// - - - /** - * Set the state of a feature. - * - *This will always fail if the parent is null.
- * - * @param name The feature name. - * @param state The requested feature state. - * @exception org.xml.sax.SAXNotRecognizedException When the - * XMLReader does not recognize the feature name. - * @exception org.xml.sax.SAXNotSupportedException When the - * XMLReader recognizes the feature name but - * cannot set the requested value. - * @see org.xml.sax.XMLReader#setFeature - */ - public void setFeature (String name, boolean state) - throws SAXNotRecognizedException, SAXNotSupportedException - { - if (parent != null) { - parent.setFeature(name, state); - } else { - throw new SAXNotRecognizedException("Feature: " + name); - } - } - - - /** - * Look up the state of a feature. - * - *This will always fail if the parent is null.
- * - * @param name The feature name. - * @return The current state of the feature. - * @exception org.xml.sax.SAXNotRecognizedException When the - * XMLReader does not recognize the feature name. - * @exception org.xml.sax.SAXNotSupportedException When the - * XMLReader recognizes the feature name but - * cannot determine its state at this time. - * @see org.xml.sax.XMLReader#getFeature - */ - public boolean getFeature (String name) - throws SAXNotRecognizedException, SAXNotSupportedException - { - if (parent != null) { - return parent.getFeature(name); - } else { - throw new SAXNotRecognizedException("Feature: " + name); - } - } - - - /** - * Set the value of a property. - * - *This will always fail if the parent is null.
- * - * @param name The property name. - * @param state The requested property value. - * @exception org.xml.sax.SAXNotRecognizedException When the - * XMLReader does not recognize the property name. - * @exception org.xml.sax.SAXNotSupportedException When the - * XMLReader recognizes the property name but - * cannot set the requested value. - * @see org.xml.sax.XMLReader#setProperty - */ - public void setProperty (String name, Object value) - throws SAXNotRecognizedException, SAXNotSupportedException - { - if (parent != null) { - parent.setProperty(name, value); - } else { - throw new SAXNotRecognizedException("Property: " + name); - } - } - - - /** - * Look up the value of a property. - * - * @param name The property name. - * @return The current value of the property. - * @exception org.xml.sax.SAXNotRecognizedException When the - * XMLReader does not recognize the feature name. - * @exception org.xml.sax.SAXNotSupportedException When the - * XMLReader recognizes the property name but - * cannot determine its value at this time. - * @see org.xml.sax.XMLReader#setFeature - */ - public Object getProperty (String name) - throws SAXNotRecognizedException, SAXNotSupportedException - { - if (parent != null) { - return parent.getProperty(name); - } else { - throw new SAXNotRecognizedException("Property: " + name); - } - } - - - /** - * Set the entity resolver. - * - * @param resolver The new entity resolver. - * @exception java.lang.NullPointerException If the resolver - * is null. - * @see org.xml.sax.XMLReader#setEntityResolver - */ - public void setEntityResolver (EntityResolver resolver) - { - if (resolver == null) { - throw new NullPointerException("Null entity resolver"); - } else { - entityResolver = resolver; - } - } - - - /** - * Get the current entity resolver. - * - * @return The current entity resolver, or null if none was set. - * @see org.xml.sax.XMLReader#getEntityResolver - */ - public EntityResolver getEntityResolver () - { - return entityResolver; - } - - - /** - * Set the DTD event handler. - * - * @param resolver The new DTD handler. - * @exception java.lang.NullPointerException If the handler - * is null. - * @see org.xml.sax.XMLReader#setDTDHandler - */ - public void setDTDHandler (DTDHandler handler) - { - if (handler == null) { - throw new NullPointerException("Null DTD handler"); - } else { - dtdHandler = handler; - } - } - - - /** - * Get the current DTD event handler. - * - * @return The current DTD handler, or null if none was set. - * @see org.xml.sax.XMLReader#getDTDHandler - */ - public DTDHandler getDTDHandler () - { - return dtdHandler; - } - - - /** - * Set the content event handler. - * - * @param resolver The new content handler. - * @exception java.lang.NullPointerException If the handler - * is null. - * @see org.xml.sax.XMLReader#setContentHandler - */ - public void setContentHandler (ContentHandler handler) - { - if (handler == null) { - throw new NullPointerException("Null content handler"); - } else { - contentHandler = handler; - } - } - - - /** - * Get the content event handler. - * - * @return The current content handler, or null if none was set. - * @see org.xml.sax.XMLReader#getContentHandler - */ - public ContentHandler getContentHandler () - { - return contentHandler; - } - - - /** - * Set the error event handler. - * - * @param handle The new error handler. - * @exception java.lang.NullPointerException If the handler - * is null. - * @see org.xml.sax.XMLReader#setErrorHandler - */ - public void setErrorHandler (ErrorHandler handler) - { - if (handler == null) { - throw new NullPointerException("Null error handler"); - } else { - errorHandler = handler; - } - } - - - /** - * Get the current error event handler. - * - * @return The current error handler, or null if none was set. - * @see org.xml.sax.XMLReader#getErrorHandler - */ - public ErrorHandler getErrorHandler () - { - return errorHandler; - } - - - /** - * Parse a document. - * - * @param input The input source for the document entity. - * @exception org.xml.sax.SAXException Any SAX exception, possibly - * wrapping another exception. - * @exception java.io.IOException An IO exception from the parser, - * possibly from a byte stream or character stream - * supplied by the application. - * @see org.xml.sax.XMLReader#parse(org.xml.sax.InputSource) - */ - public void parse (InputSource input) - throws SAXException, IOException - { - setupParse(); - parent.parse(input); - } - - - /** - * Parse a document. - * - * @param systemId The system identifier as a fully-qualified URI. - * @exception org.xml.sax.SAXException Any SAX exception, possibly - * wrapping another exception. - * @exception java.io.IOException An IO exception from the parser, - * possibly from a byte stream or character stream - * supplied by the application. - * @see org.xml.sax.XMLReader#parse(java.lang.String) - */ - public void parse (String systemId) - throws SAXException, IOException - { - parse(new InputSource(systemId)); - } - - - - //////////////////////////////////////////////////////////////////// - // Implementation of org.xml.sax.EntityResolver. - //////////////////////////////////////////////////////////////////// - - - /** - * Filter an external entity resolution. - * - * @param publicId The entity's public identifier, or null. - * @param systemId The entity's system identifier. - * @return A new InputSource or null for the default. - * @exception org.xml.sax.SAXException The client may throw - * an exception during processing. - * @exception java.io.IOException The client may throw an - * I/O-related exception while obtaining the - * new InputSource. - * @see org.xml.sax.EntityResolver#resolveEntity - */ - public InputSource resolveEntity (String publicId, String systemId) - throws SAXException, IOException - { - if (entityResolver != null) { - return entityResolver.resolveEntity(publicId, systemId); - } else { - return null; - } - } - - - - //////////////////////////////////////////////////////////////////// - // Implementation of org.xml.sax.DTDHandler. - //////////////////////////////////////////////////////////////////// - - - /** - * Filter a notation declaration event. - * - * @param name The notation name. - * @param publicId The notation's public identifier, or null. - * @param systemId The notation's system identifier, or null. - * @exception org.xml.sax.SAXException The client may throw - * an exception during processing. - * @see org.xml.sax.DTDHandler#notationDecl - */ - public void notationDecl (String name, String publicId, String systemId) - throws SAXException - { - if (dtdHandler != null) { - dtdHandler.notationDecl(name, publicId, systemId); - } - } - - - /** - * Filter an unparsed entity declaration event. - * - * @param name The entity name. - * @param publicId The entity's public identifier, or null. - * @param systemId The entity's system identifier, or null. - * @param notationName The name of the associated notation. - * @exception org.xml.sax.SAXException The client may throw - * an exception during processing. - * @see org.xml.sax.DTDHandler#unparsedEntityDecl - */ - public void unparsedEntityDecl (String name, String publicId, - String systemId, String notationName) - throws SAXException - { - if (dtdHandler != null) { - dtdHandler.unparsedEntityDecl(name, publicId, systemId, - notationName); - } - } - - - - //////////////////////////////////////////////////////////////////// - // Implementation of org.xml.sax.ContentHandler. - //////////////////////////////////////////////////////////////////// - - - /** - * Filter a new document locator event. - * - * @param locator The document locator. - * @see org.xml.sax.ContentHandler#setDocumentLocator - */ - public void setDocumentLocator (Locator locator) - { - this.locator = locator; - if (contentHandler != null) { - contentHandler.setDocumentLocator(locator); - } - } - - - /** - * Filter a start document event. - * - * @exception org.xml.sax.SAXException The client may throw - * an exception during processing. - * @see org.xml.sax.ContentHandler#startDocument - */ - public void startDocument () - throws SAXException - { - if (contentHandler != null) { - contentHandler.startDocument(); - } - } - - - /** - * Filter an end document event. - * - * @exception org.xml.sax.SAXException The client may throw - * an exception during processing. - * @see org.xml.sax.ContentHandler#endDocument - */ - public void endDocument () - throws SAXException - { - if (contentHandler != null) { - contentHandler.endDocument(); - } - } - - - /** - * Filter a start Namespace prefix mapping event. - * - * @param prefix The Namespace prefix. - * @param uri The Namespace URI. - * @exception org.xml.sax.SAXException The client may throw - * an exception during processing. - * @see org.xml.sax.ContentHandler#startPrefixMapping - */ - public void startPrefixMapping (String prefix, String uri) - throws SAXException - { - if (contentHandler != null) { - contentHandler.startPrefixMapping(prefix, uri); - } - } - - - /** - * Filter an end Namespace prefix mapping event. - * - * @param prefix The Namespace prefix. - * @exception org.xml.sax.SAXException The client may throw - * an exception during processing. - * @see org.xml.sax.ContentHandler#endPrefixMapping - */ - public void endPrefixMapping (String prefix) - throws SAXException - { - if (contentHandler != null) { - contentHandler.endPrefixMapping(prefix); - } - } - - - /** - * Filter a start element event. - * - * @param uri The element's Namespace URI, or the empty string. - * @param localName The element's local name, or the empty string. - * @param qName The element's qualified (prefixed) name, or the empty - * string. - * @param atts The element's attributes. - * @exception org.xml.sax.SAXException The client may throw - * an exception during processing. - * @see org.xml.sax.ContentHandler#startElement - */ - public void startElement (String uri, String localName, String qName, - Attributes atts) - throws SAXException - { - if (contentHandler != null) { - contentHandler.startElement(uri, localName, qName, atts); - } - } - - - /** - * Filter an end element event. - * - * @param uri The element's Namespace URI, or the empty string. - * @param localName The element's local name, or the empty string. - * @param qName The element's qualified (prefixed) name, or the empty - * string. - * @exception org.xml.sax.SAXException The client may throw - * an exception during processing. - * @see org.xml.sax.ContentHandler#endElement - */ - public void endElement (String uri, String localName, String qName) - throws SAXException - { - if (contentHandler != null) { - contentHandler.endElement(uri, localName, qName); - } - } - - - /** - * Filter a character data event. - * - * @param ch An array of characters. - * @param start The starting position in the array. - * @param length The number of characters to use from the array. - * @exception org.xml.sax.SAXException The client may throw - * an exception during processing. - * @see org.xml.sax.ContentHandler#characters - */ - public void characters (char ch[], int start, int length) - throws SAXException - { - if (contentHandler != null) { - contentHandler.characters(ch, start, length); - } - } - - - /** - * Filter an ignorable whitespace event. - * - * @param ch An array of characters. - * @param start The starting position in the array. - * @param length The number of characters to use from the array. - * @exception org.xml.sax.SAXException The client may throw - * an exception during processing. - * @see org.xml.sax.ContentHandler#ignorableWhitespace - */ - public void ignorableWhitespace (char ch[], int start, int length) - throws SAXException - { - if (contentHandler != null) { - contentHandler.ignorableWhitespace(ch, start, length); - } - } - - - /** - * Filter a processing instruction event. - * - * @param target The processing instruction target. - * @param data The text following the target. - * @exception org.xml.sax.SAXException The client may throw - * an exception during processing. - * @see org.xml.sax.ContentHandler#processingInstruction - */ - public void processingInstruction (String target, String data) - throws SAXException - { - if (contentHandler != null) { - contentHandler.processingInstruction(target, data); - } - } - - - /** - * Filter a skipped entity event. - * - * @param name The name of the skipped entity. - * @exception org.xml.sax.SAXException The client may throw - * an exception during processing. - * @see org.xml.sax.ContentHandler#skippedEntity - */ - public void skippedEntity (String name) - throws SAXException - { - if (contentHandler != null) { - contentHandler.skippedEntity(name); - } - } - - - - //////////////////////////////////////////////////////////////////// - // Implementation of org.xml.sax.ErrorHandler. - //////////////////////////////////////////////////////////////////// - - - /** - * Filter a warning event. - * - * @param e The nwarning as an exception. - * @exception org.xml.sax.SAXException The client may throw - * an exception during processing. - * @see org.xml.sax.ErrorHandler#warning - */ - public void warning (SAXParseException e) - throws SAXException - { - if (errorHandler != null) { - errorHandler.warning(e); - } - } - - - /** - * Filter an error event. - * - * @param e The error as an exception. - * @exception org.xml.sax.SAXException The client may throw - * an exception during processing. - * @see org.xml.sax.ErrorHandler#error - */ - public void error (SAXParseException e) - throws SAXException - { - if (errorHandler != null) { - errorHandler.error(e); - } - } - - - /** - * Filter a fatal error event. - * - * @param e The error as an exception. - * @exception org.xml.sax.SAXException The client may throw - * an exception during processing. - * @see org.xml.sax.ErrorHandler#fatalError - */ - public void fatalError (SAXParseException e) - throws SAXException - { - if (errorHandler != null) { - errorHandler.fatalError(e); - } - } - - - - //////////////////////////////////////////////////////////////////// - // Internal methods. - //////////////////////////////////////////////////////////////////// - - - /** - * Set up before a parse. - * - *Before every parse, check whether the parent is - * non-null, and re-register the filter for all of the - * events.
- */ - private void setupParse () - { - if (parent == null) { - throw new NullPointerException("No parent for filter"); - } - parent.setEntityResolver(this); - parent.setDTDHandler(this); - parent.setContentHandler(this); - parent.setErrorHandler(this); - } - - - - //////////////////////////////////////////////////////////////////// - // Internal state. - //////////////////////////////////////////////////////////////////// - - private XMLReader parent = null; - private Locator locator = null; - private EntityResolver entityResolver = null; - private DTDHandler dtdHandler = null; - private ContentHandler contentHandler = null; - private ErrorHandler errorHandler = null; - -} - -// end of XMLFilterImpl.java