// ParserAdapter.java - adapt a SAX1 Parser to a SAX2 XMLReader.
// http://www.saxproject.org
// Written by David Megginson
// NO WARRANTY! This class is in the public domain.
// $Id: ParserAdapter.java,v 1.3 2004/11/03 22:53:09 jsuttor Exp $
package org.xml.sax.helpers;
import java.io.IOException;
import java.util.Enumeration;
import java.util.Vector;
import org.xml.sax.Parser; // deprecated
import org.xml.sax.InputSource;
import org.xml.sax.Locator;
import org.xml.sax.AttributeList; // deprecated
import org.xml.sax.EntityResolver;
import org.xml.sax.DTDHandler;
import org.xml.sax.DocumentHandler; // deprecated
import org.xml.sax.ErrorHandler;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;
import org.xml.sax.XMLReader;
import org.xml.sax.Attributes;
import org.xml.sax.ContentHandler;
import org.xml.sax.SAXNotRecognizedException;
import org.xml.sax.SAXNotSupportedException;
/**
* Adapt a SAX1 Parser as a SAX2 XMLReader.
*
* <blockquote>
* <em>This module, both source code and documentation, is in the
* Public Domain, and comes with <strong>NO WARRANTY</strong>.</em>
* See <a href='http://www.saxproject.org'>http://www.saxproject.org</a>
* for further information.
* </blockquote>
*
* <p>This class wraps a SAX1 {@link org.xml.sax.Parser Parser}
* and makes it act as a SAX2 {@link org.xml.sax.XMLReader XMLReader},
* with feature, property, and Namespace support. Note
* that it is not possible to report {@link org.xml.sax.ContentHandler#skippedEntity
* skippedEntity} events, since SAX1 does not make that information available.</p>
*
* <p>This adapter does not test for duplicate Namespace-qualified
* attribute names.</p>
*
* @since SAX 2.0
* @author David Megginson
* @version 2.0.1 (sax2r2)
* @see org.xml.sax.helpers.XMLReaderAdapter
* @see org.xml.sax.XMLReader
* @see org.xml.sax.Parser
*/
public class ParserAdapter implements XMLReader, DocumentHandler
{
////////////////////////////////////////////////////////////////////
// Constructors.
////////////////////////////////////////////////////////////////////
/**
* Construct a new parser adapter.
*
* <p>Use the "org.xml.sax.parser" property to locate the
* embedded SAX1 driver.</p>
*
* @exception SAXException If the embedded driver
* cannot be instantiated or if the
* org.xml.sax.parser property is not specified.
*/
public ParserAdapter ()
throws SAXException
{
super();
String driver = System.getProperty("org.xml.sax.parser");
try {
setup(ParserFactory.makeParser());
} catch (ClassNotFoundException e1) {
throw new
SAXException("Cannot find SAX1 driver class " +
driver, e1);
} catch (IllegalAccessException e2) {
throw new
SAXException("SAX1 driver class " +
driver +
" found but cannot be loaded", e2);
} catch (InstantiationException e3) {
throw new
SAXException("SAX1 driver class " +
driver +
" loaded but cannot be instantiated", e3);
} catch (ClassCastException e4) {
throw new
SAXException("SAX1 driver class " +
driver +
" does not implement org.xml.sax.Parser");
} catch (NullPointerException e5) {
throw new
SAXException("System property org.xml.sax.parser not specified");
}
}
/**
* Construct a new parser adapter.
*
* <p>Note that the embedded parser cannot be changed once the
* adapter is created; to embed a different parser, allocate
* a new ParserAdapter.</p>
*
* @param parser The SAX1 parser to embed.
* @exception java.lang.NullPointerException If the parser parameter
* is null.
*/
public ParserAdapter (Parser parser)
{
super();
setup(parser);
}
/**
* Internal setup method.
*
* @param parser The embedded parser.
* @exception java.lang.NullPointerException If the parser parameter
* is null.
*/
private void setup (Parser parser)
{
if (parser == null) {
throw new
NullPointerException("Parser argument must not be null");
}
this.parser = parser;
atts = new AttributesImpl();
nsSupport = new NamespaceSupport();
attAdapter = new AttributeListAdapter();
}
////////////////////////////////////////////////////////////////////
// Implementation of org.xml.sax.XMLReader.
////////////////////////////////////////////////////////////////////
//
// Internal constants for the sake of convenience.
//
private final static String FEATURES = "http://xml.org/sax/features/";
private final static String NAMESPACES = FEATURES + "namespaces";
private final static String NAMESPACE_PREFIXES = FEATURES + "namespace-prefixes";
private final static String XMLNS_URIs = FEATURES + "xmlns-uris";
/**
* Set a feature flag for the parser.
*
* <p>The only features recognized are namespaces and
* namespace-prefixes.</p>
*
* @param name The feature name, as a complete URI.
* @param value The requested feature value.
* @exception SAXNotRecognizedException If the feature
* can't be assigned or retrieved.
* @exception SAXNotSupportedException If the feature
* can't be assigned that value.
* @see org.xml.sax.XMLReader#setFeature
*/
public void setFeature (String name, boolean value)
throws SAXNotRecognizedException, SAXNotSupportedException
{
if (name.equals(NAMESPACES)) {
checkNotParsing("feature", name);
namespaces = value;
if (!namespaces && !prefixes) {
prefixes = true;
}
} else if (name.equals(NAMESPACE_PREFIXES)) {
checkNotParsing("feature", name);
prefixes = value;
if (!prefixes && !namespaces) {
namespaces = true;
}
} else if (name.equals(XMLNS_URIs)) {
checkNotParsing("feature", name);
uris = value;
} else {
throw new SAXNotRecognizedException("Feature: " + name);
}
}
/**
* Check a parser feature flag.
*
* <p>The only features recognized are namespaces and
* namespace-prefixes.</p>
*
* @param name The feature name, as a complete URI.
* @return The current feature value.
* @exception SAXNotRecognizedException If the feature
* value can't be assigned or retrieved.
* @exception SAXNotSupportedException If the
* feature is not currently readable.
* @see org.xml.sax.XMLReader#setFeature
*/
public boolean getFeature (String name)
throws SAXNotRecognizedException, SAXNotSupportedException
{
if (name.equals(NAMESPACES)) {
return namespaces;
} else if (name.equals(NAMESPACE_PREFIXES)) {
return prefixes;
} else if (name.equals(XMLNS_URIs)) {
return uris;
} else {
throw new SAXNotRecognizedException("Feature: " + name);
}
}
/**
* Set a parser property.
*
* <p>No properties are currently recognized.</p>
*
* @param name The property name.
* @param value The property value.
* @exception SAXNotRecognizedException If the property
* value can't be assigned or retrieved.
* @exception SAXNotSupportedException If the property
* can't be assigned that value.
* @see org.xml.sax.XMLReader#setProperty
*/
public void setProperty (String name, Object value)
throws SAXNotRecognizedException, SAXNotSupportedException
{
throw new SAXNotRecognizedException("Property: " + name);
}
/**
* Get a parser property.
*
* <p>No properties are currently recognized.</p>
*
* @param name The property name.
* @return The property value.
* @exception SAXNotRecognizedException If the property
* value can't be assigned or retrieved.
* @exception SAXNotSupportedException If the property
* value is not currently readable.
* @see org.xml.sax.XMLReader#getProperty
*/
public Object getProperty (String name)
throws SAXNotRecognizedException, SAXNotSupportedException
{
throw new SAXNotRecognizedException("Property: " + name);
}
/**
* Set the entity resolver.
*
* @param resolver The new entity resolver.
* @see org.xml.sax.XMLReader#setEntityResolver
*/
public void setEntityResolver (EntityResolver resolver)
{
entityResolver = resolver;
}
/**
* Return the current entity resolver.
*
* @return The current entity resolver, or null if none was supplied.
* @see org.xml.sax.XMLReader#getEntityResolver
*/
public EntityResolver getEntityResolver ()
{
return entityResolver;
}
/**
* Set the DTD handler.
*
* @param handler the new DTD handler
* @see org.xml.sax.XMLReader#setEntityResolver
*/
public void setDTDHandler (DTDHandler handler)
{
dtdHandler = handler;
}
/**
* Return the current DTD handler.
*
* @return the current DTD handler, or null if none was supplied
* @see org.xml.sax.XMLReader#getEntityResolver
*/
public DTDHandler getDTDHandler ()
{
return dtdHandler;
}
/**
* Set the content handler.
*
* @param handler the new content handler
* @see org.xml.sax.XMLReader#setEntityResolver
*/
public void setContentHandler (ContentHandler handler)
{
contentHandler = handler;
}
/**
* Return the current content handler.
*
* @return The current content handler, or null if none was supplied.
* @see org.xml.sax.XMLReader#getEntityResolver
*/
public ContentHandler getContentHandler ()
{
return contentHandler;
}
/**
* Set the error handler.
*
* @param handler The new error handler.
* @see org.xml.sax.XMLReader#setEntityResolver
*/
public void setErrorHandler (ErrorHandler handler)
{
errorHandler = handler;
}
/**
* Return the current error handler.
*
* @return The current error handler, or null if none was supplied.
* @see org.xml.sax.XMLReader#getEntityResolver
*/
public ErrorHandler getErrorHandler ()
{
return errorHandler;
}
/**
* Parse an XML document.
*
* @param systemId The absolute URL of the document.
* @exception java.io.IOException If there is a problem reading
* the raw content of the document.
* @exception SAXException If there is a problem
* processing the document.
* @see #parse(org.xml.sax.InputSource)
* @see org.xml.sax.Parser#parse(java.lang.String)
*/
public void parse (String systemId)
throws IOException, SAXException
{
parse(new InputSource(systemId));
}
/**
* Parse an XML document.
*
* @param input An input source for the document.
* @exception java.io.IOException If there is a problem reading
* the raw content of the document.
* @exception SAXException If there is a problem
* processing the document.
* @see #parse(java.lang.String)
* @see org.xml.sax.Parser#parse(org.xml.sax.InputSource)
*/
public void parse (InputSource input)
throws IOException, SAXException
{
if (parsing) {
throw new SAXException("Parser is already in use");
}
setupParser();
parsing = true;
try {
parser.parse(input);
} finally {
parsing = false;
}
parsing = false;
}
////////////////////////////////////////////////////////////////////
// Implementation of org.xml.sax.DocumentHandler.
////////////////////////////////////////////////////////////////////
/**
* Adapter implementation method; do not call.
* Adapt a SAX1 document locator event.
*
* @param locator A document locator.
* @see org.xml.sax.ContentHandler#setDocumentLocator
*/
public void setDocumentLocator (Locator locator)
{
this.locator = locator;
if (contentHandler != null) {
contentHandler.setDocumentLocator(locator);
}
}
/**
* Adapter implementation method; do not call.
* Adapt a SAX1 start document event.
*
* @exception SAXException The client may raise a
* processing exception.
* @see org.xml.sax.DocumentHandler#startDocument
*/
public void startDocument ()
throws SAXException
{
if (contentHandler != null) {
contentHandler.startDocument();
}
}
/**
* Adapter implementation method; do not call.
* Adapt a SAX1 end document event.
*
* @exception SAXException The client may raise a
* processing exception.
* @see org.xml.sax.DocumentHandler#endDocument
*/
public void endDocument ()
throws SAXException
{
if (contentHandler != null) {
contentHandler.endDocument();
}
}
/**
* Adapter implementation method; do not call.
* Adapt a SAX1 startElement event.
*
* <p>If necessary, perform Namespace processing.</p>
*
* @param qName The qualified (prefixed) name.
* @param qAtts The XML attribute list (with qnames).
* @exception SAXException The client may raise a
* processing exception.
*/
public void startElement (String qName, AttributeList qAtts)
throws SAXException
{
// These are exceptions from the
// first pass; they should be
// ignored if there's a second pass,
// but reported otherwise.
Vector exceptions = null;
// If we're not doing Namespace
// processing, dispatch this quickly.
if (!namespaces) {
if (contentHandler != null) {
attAdapter.setAttributeList(qAtts);
contentHandler.startElement("", "", qName.intern(),
attAdapter);
}
return;
}
// OK, we're doing Namespace processing.
nsSupport.pushContext();
int length = qAtts.getLength();
// First pass: handle NS decls
for (int i = 0; i < length; i++) {
String attQName = qAtts.getName(i);
if (!attQName.startsWith("xmlns"))
continue;
// Could be a declaration...
String prefix;
int n = attQName.indexOf(':');
// xmlns=...
if (n == -1 && attQName.length () == 5) {
prefix = "";
} else if (n != 5) {
// XML namespaces spec doesn't discuss "xmlnsf:oo"
// (and similarly named) attributes ... at most, warn
continue;
} else // xmlns:foo=...
prefix = attQName.substring(n+1);
String value = qAtts.getValue(i);
if (!nsSupport.declarePrefix(prefix, value)) {
reportError("Illegal Namespace prefix: " + prefix);
continue;
}
if (contentHandler != null)
contentHandler.startPrefixMapping(prefix, value);
}
// Second pass: copy all relevant
// attributes into the SAX2 AttributeList
// using updated prefix bindings
atts.clear();
for (int i = 0; i < length; i++) {
String attQName = qAtts.getName(i);
String type = qAtts.getType(i);
String value = qAtts.getValue(i);
// Declaration?
if (attQName.startsWith("xmlns")) {
String prefix;
int n = attQName.indexOf(':');
if (n == -1 && attQName.length () == 5) {
prefix = "";
} else if (n != 5) {
// XML namespaces spec doesn't discuss "xmlnsf:oo"
// (and similarly named) attributes ... ignore
prefix = null;
} else {
prefix = attQName.substring(6);
}
// Yes, decl: report or prune
if (prefix != null) {
if (prefixes) {
if (uris)
// note funky case: localname can be null
// when declaring the default prefix, and
// yet the uri isn't null.
atts.addAttribute (nsSupport.XMLNS, prefix,
attQName.intern(), type, value);
else
atts.addAttribute ("", "",
attQName.intern(), type, value);
}
continue;
}
}
// Not a declaration -- report
try {
String attName[] = processName(attQName, true, true);
atts.addAttribute(attName[0], attName[1], attName[2],
type, value);
} catch (SAXException e) {
if (exceptions == null)
exceptions = new Vector();
exceptions.addElement(e);
atts.addAttribute("", attQName, attQName, type, value);
}
}
// now handle the deferred exception reports
if (exceptions != null && errorHandler != null) {
for (int i = 0; i < exceptions.size(); i++)
errorHandler.error((SAXParseException)
(exceptions.elementAt(i)));
}
// OK, finally report the event.
if (contentHandler != null) {
String name[] = processName(qName, false, false);
contentHandler.startElement(name[0], name[1], name[2], atts);
}
}
/**
* Adapter implementation method; do not call.
* Adapt a SAX1 end element event.
*
* @param qName The qualified (prefixed) name.
* @exception SAXException The client may raise a
* processing exception.
* @see org.xml.sax.DocumentHandler#endElement
*/
public void endElement (String qName)
throws SAXException
{
// If we're not doing Namespace
// processing, dispatch this quickly.
if (!namespaces) {
if (contentHandler != null) {
contentHandler.endElement("", "", qName.intern());
}
return;
}
// Split the name.
String names[] = processName(qName, false, false);
if (contentHandler != null) {
contentHandler.endElement(names[0], names[1], names[2]);
Enumeration prefixes = nsSupport.getDeclaredPrefixes();
while (prefixes.hasMoreElements()) {
String prefix = (String)prefixes.nextElement();
contentHandler.endPrefixMapping(prefix);
}
}
nsSupport.popContext();
}
/**
* Adapter implementation method; do not call.
* Adapt a SAX1 characters event.
*
* @param ch An array of characters.
* @param start The starting position in the array.
* @param length The number of characters to use.
* @exception SAXException The client may raise a
* processing exception.
* @see org.xml.sax.DocumentHandler#characters
*/
public void characters (char ch[], int start, int length)
throws SAXException
{
if (contentHandler != null) {
contentHandler.characters(ch, start, length);
}
}
/**
* Adapter implementation method; do not call.
* Adapt a SAX1 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.
* @exception SAXException The client may raise a
* processing exception.
* @see org.xml.sax.DocumentHandler#ignorableWhitespace
*/
public void ignorableWhitespace (char ch[], int start, int length)
throws SAXException
{
if (contentHandler != null) {
contentHandler.ignorableWhitespace(ch, start, length);
}
}
/**
* Adapter implementation method; do not call.
* Adapt a SAX1 processing instruction event.
*
* @param target The processing instruction target.
* @param data The remainder of the processing instruction
* @exception SAXException The client may raise a
* processing exception.
* @see org.xml.sax.DocumentHandler#processingInstruction
*/
public void processingInstruction (String target, String data)
throws SAXException
{
if (contentHandler != null) {
contentHandler.processingInstruction(target, data);
}
}
////////////////////////////////////////////////////////////////////
// Internal utility methods.
////////////////////////////////////////////////////////////////////
/**
* Initialize the parser before each run.
*/
private void setupParser ()
{
// catch an illegal "nonsense" state.
if (!prefixes && !namespaces)
throw new IllegalStateException ();
nsSupport.reset();
if (uris)
nsSupport.setNamespaceDeclUris (true);
if (entityResolver != null) {
parser.setEntityResolver(entityResolver);
}
if (dtdHandler != null) {
parser.setDTDHandler(dtdHandler);
}
if (errorHandler != null) {
parser.setErrorHandler(errorHandler);
}
parser.setDocumentHandler(this);
locator = null;
}
/**
* Process a qualified (prefixed) name.
*
* <p>If the name has an undeclared prefix, use only the qname
* and make an ErrorHandler.error callback in case the app is
* interested.</p>
*
* @param qName The qualified (prefixed) name.
* @param isAttribute true if this is an attribute name.
* @return The name split into three parts.
* @exception SAXException The client may throw
* an exception if there is an error callback.
*/
private String [] processName (String qName, boolean isAttribute,
boolean useException)
throws SAXException
{
String parts[] = nsSupport.processName(qName, nameParts,
isAttribute);
if (parts == null) {
if (useException)
throw makeException("Undeclared prefix: " + qName);
reportError("Undeclared prefix: " + qName);
parts = new String[3];
parts[0] = parts[1] = "";
parts[2] = qName.intern();
}
return parts;
}
/**
* Report a non-fatal error.
*
* @param message The error message.
* @exception SAXException The client may throw
* an exception.
*/
void reportError (String message)
throws SAXException
{
if (errorHandler != null)
errorHandler.error(makeException(message));
}
/**
* Construct an exception for the current context.
*
* @param message The error message.
*/
private SAXParseException makeException (String message)
{
if (locator != null) {
return new SAXParseException(message, locator);
} else {
return new SAXParseException(message, null, null, -1, -1);
}
}
/**
* Throw an exception if we are parsing.
*
* <p>Use this method to detect illegal feature or
* property changes.</p>
*
* @param type The type of thing (feature or property).
* @param name The feature or property name.
* @exception SAXNotSupportedException If a
* document is currently being parsed.
*/
private void checkNotParsing (String type, String name)
throws SAXNotSupportedException
{
if (parsing) {
throw new SAXNotSupportedException("Cannot change " +
type + ' ' +
name + " while parsing");
}
}
////////////////////////////////////////////////////////////////////
// Internal state.
////////////////////////////////////////////////////////////////////
private NamespaceSupport nsSupport;
private AttributeListAdapter attAdapter;
private boolean parsing = false;
private String nameParts[] = new String[3];
private Parser parser = null;
private AttributesImpl atts = null;
// Features
private boolean namespaces = true;
private boolean prefixes = false;
private boolean uris = false;
// Properties
// Handlers
Locator locator;
EntityResolver entityResolver = null;
DTDHandler dtdHandler = null;
ContentHandler contentHandler = null;
ErrorHandler errorHandler = null;
////////////////////////////////////////////////////////////////////
// Inner class to wrap an AttributeList when not doing NS proc.
////////////////////////////////////////////////////////////////////
/**
* Adapt a SAX1 AttributeList as a SAX2 Attributes object.
*
* <p>This class is in the Public Domain, and comes with NO
* WARRANTY of any kind.</p>
*
* <p>This wrapper class is used only when Namespace support
* is disabled -- it provides pretty much a direct mapping
* from SAX1 to SAX2, except that names and types are
* interned whenever requested.</p>
*/
final class AttributeListAdapter implements Attributes
{
/**
* Construct a new adapter.
*/
AttributeListAdapter ()
{
}
/**
* Set the embedded AttributeList.
*
* <p>This method must be invoked before any of the others
* can be used.</p>
*
* @param The SAX1 attribute list (with qnames).
*/
void setAttributeList (AttributeList qAtts)
{
this.qAtts = qAtts;
}
/**
* Return the length of the attribute list.
*
* @return The number of attributes in the list.
* @see org.xml.sax.Attributes#getLength
*/
public int getLength ()
{
return qAtts.getLength();
}
/**
* Return the Namespace URI of the specified attribute.
*
* @param The attribute's index.
* @return Always the empty string.
* @see org.xml.sax.Attributes#getURI
*/
public String getURI (int i)
{
return "";
}
/**
* Return the local name of the specified attribute.
*
* @param The attribute's index.
* @return Always the empty string.
* @see org.xml.sax.Attributes#getLocalName
*/
public String getLocalName (int i)
{
return "";
}
/**
* Return the qualified (prefixed) name of the specified attribute.
*
* @param The attribute's index.
* @return The attribute's qualified name, internalized.
*/
public String getQName (int i)
{
return qAtts.getName(i).intern();
}
/**
* Return the type of the specified attribute.
*
* @param The attribute's index.
* @return The attribute's type as an internalized string.
*/
public String getType (int i)
{
return qAtts.getType(i).intern();
}
/**
* Return the value of the specified attribute.
*
* @param The attribute's index.
* @return The attribute's value.
*/
public String getValue (int i)
{
return qAtts.getValue(i);
}
/**
* Look up an attribute index by Namespace name.
*
* @param uri The Namespace URI or the empty string.
* @param localName The local name.
* @return The attributes index, or -1 if none was found.
* @see org.xml.sax.Attributes#getIndex(java.lang.String,java.lang.String)
*/
public int getIndex (String uri, String localName)
{
return -1;
}
/**
* Look up an attribute index by qualified (prefixed) name.
*
* @param qName The qualified name.
* @return The attributes index, or -1 if none was found.
* @see org.xml.sax.Attributes#getIndex(java.lang.String)
*/
public int getIndex (String qName)
{
int max = atts.getLength();
for (int i = 0; i < max; i++) {
if (qAtts.getName(i).equals(qName)) {
return i;
}
}
return -1;
}
/**
* Look up the type of an attribute by Namespace name.
*
* @param uri The Namespace URI
* @param localName The local name.
* @return The attribute's type as an internalized string.
*/
public String getType (String uri, String localName)
{
return null;
}
/**
* Look up the type of an attribute by qualified (prefixed) name.
*
* @param qName The qualified name.
* @return The attribute's type as an internalized string.
*/
public String getType (String qName)
{
return qAtts.getType(qName).intern();
}
/**
* Look up the value of an attribute by Namespace name.
*
* @param uri The Namespace URI
* @param localName The local name.
* @return The attribute's value.
*/
public String getValue (String uri, String localName)
{
return null;
}
/**
* Look up the value of an attribute by qualified (prefixed) name.
*
* @param qName The qualified name.
* @return The attribute's value.
*/
public String getValue (String qName)
{
return qAtts.getValue(qName);
}
private AttributeList qAtts;
}
}
// end of ParserAdapter.java
|
