* The DOM API requires that it be a real object rather than static * methods. However, there's nothing that says it can't be a singleton, * so that's how I've implemented it. *
* This particular class, along with CoreDocumentImpl, supports the DOM * Core and Load/Save (Experimental). Optional modules are supported by * the more complete DOMImplementation class along with DocumentImpl. * @version $Id: CoreDOMImplementationImpl.java,v 1.30 2004/02/17 07:14:48 neeraj Exp $ * @since PR-DOM-Level-1-19980818. */ public class CoreDOMImplementationImpl implements DOMImplementation, DOMImplementationLS { // // Data // // validators pool private static final int SIZE = 2; private RevalidationHandler validators[] = new RevalidationHandler[SIZE]; private int freeValidatorIndex = -1; private int currentSize = SIZE; // Document and doctype counter. Used to assign order to documents and // doctypes without owners, on an demand basis. Used for // compareDocumentPosition private int docAndDoctypeCounter = 0; // static /** Dom implementation singleton. */ static CoreDOMImplementationImpl singleton = new CoreDOMImplementationImpl(); // // Public methods // /** NON-DOM: Obtain and return the single shared object */ public static DOMImplementation getDOMImplementation() { return singleton; } // // DOMImplementation methods // /** * Test if the DOM implementation supports a specific "feature" -- * currently meaning language and level thereof. * * @param feature The package name of the feature to test. * In Level 1, supported values are "HTML" and "XML" (case-insensitive). * At this writing, com.sun.org.apache.xerces.internal.dom supports only XML. * * @param version The version number of the feature being tested. * This is interpreted as "Version of the DOM API supported for the * specified Feature", and in Level 1 should be "1.0" * * @return true iff this implementation is compatable with the specified * feature and version. */ public boolean hasFeature(String feature, String version) { boolean anyVersion = version == null || version.length() == 0; if (feature.startsWith("+")) { feature = feature.substring(1); } // check if Xalan implementation is around and if yes report true for supporting // XPath API if ((feature.equalsIgnoreCase("XPath") || feature.equalsIgnoreCase("+XPath")) && (anyVersion || version.equals("3.0"))) { try { Class xpathClass = ObjectFactory.findProviderClass( "com.sun.org.apache.xpath.internal.domapi.XPathEvaluatorImpl", ObjectFactory.findClassLoader(), true); } catch (Exception e) { return false; } return true; } return ( feature.equalsIgnoreCase("Core") && (anyVersion || version.equals("1.0") || version.equals("2.0") || version.equals("3.0"))) || (feature.equalsIgnoreCase("XML") && (anyVersion || version.equals("1.0") || version.equals("2.0") || version.equals("3.0"))) || (feature.equalsIgnoreCase("LS") && (anyVersion || version.equals("3.0"))); } // hasFeature(String,String):boolean /** * Introduced in DOM Level 2.
* * Creates an empty DocumentType node. * * @param qualifiedName The qualified name of the document type to be created. * @param publicID The document type public identifier. * @param systemID The document type system identifier. * @since WD-DOM-Level-2-19990923 */ public DocumentType createDocumentType( String qualifiedName, String publicID, String systemID) { // REVISIT: this might allow creation of invalid name for DOCTYPE // xmlns prefix. // also there is no way for a user to turn off error checking. checkQName(qualifiedName); return new DocumentTypeImpl(null, qualifiedName, publicID, systemID); } final void checkQName(String qname){ int index = qname.indexOf(':'); int lastIndex = qname.lastIndexOf(':'); int length = qname.length(); // it is an error for NCName to have more than one ':' // check if it is valid QName [Namespace in XML production 6] if (index == 0 || index == length - 1 || lastIndex != index) { String msg = DOMMessageFormatter.formatMessage( DOMMessageFormatter.DOM_DOMAIN, "NAMESPACE_ERR", null); throw new DOMException(DOMException.NAMESPACE_ERR, msg); } int start = 0; // Namespace in XML production [6] if (index > 0) { // check that prefix is NCName if (!XMLChar.isNCNameStart(qname.charAt(start))) { String msg = DOMMessageFormatter.formatMessage( DOMMessageFormatter.DOM_DOMAIN, "INVALID_CHARACTER_ERR", null); throw new DOMException(DOMException.INVALID_CHARACTER_ERR, msg); } for (int i = 1; i < index; i++) { if (!XMLChar.isNCName(qname.charAt(i))) { String msg = DOMMessageFormatter.formatMessage( DOMMessageFormatter.DOM_DOMAIN, "INVALID_CHARACTER_ERR", null); throw new DOMException( DOMException.INVALID_CHARACTER_ERR, msg); } } start = index + 1; } // check local part if (!XMLChar.isNCNameStart(qname.charAt(start))) { // REVISIT: add qname parameter to the message String msg = DOMMessageFormatter.formatMessage( DOMMessageFormatter.DOM_DOMAIN, "INVALID_CHARACTER_ERR", null); throw new DOMException(DOMException.INVALID_CHARACTER_ERR, msg); } for (int i = start + 1; i < length; i++) { if (!XMLChar.isNCName(qname.charAt(i))) { String msg = DOMMessageFormatter.formatMessage( DOMMessageFormatter.DOM_DOMAIN, "INVALID_CHARACTER_ERR", null); throw new DOMException(DOMException.INVALID_CHARACTER_ERR, msg); } } } /** * Introduced in DOM Level 2.
* * Creates an XML Document object of the specified type with its document * element. * * @param namespaceURI The namespace URI of the document * element to create, or null. * @param qualifiedName The qualified name of the document * element to create. * @param doctype The type of document to be created or null.
*
* When doctype is not null, its
* Node.ownerDocument attribute is set to
* the document being created.
* @return Document A new Document object.
* @throws DOMException WRONG_DOCUMENT_ERR: Raised if doctype has
* already been used with a different document.
* @since WD-DOM-Level-2-19990923
*/
public Document createDocument(
String namespaceURI,
String qualifiedName,
DocumentType doctype)
throws DOMException {
if (doctype != null && doctype.getOwnerDocument() != null) {
String msg =
DOMMessageFormatter.formatMessage(
DOMMessageFormatter.DOM_DOMAIN,
"WRONG_DOCUMENT_ERR",
null);
throw new DOMException(DOMException.WRONG_DOCUMENT_ERR, msg);
}
CoreDocumentImpl doc = new CoreDocumentImpl(doctype);
Element e = doc.createElementNS(namespaceURI, qualifiedName);
doc.appendChild(e);
return doc;
}
/**
* DOM Level 3 WD - Experimental.
*/
public Object getFeature(String feature, String version) {
if (singleton.hasFeature(feature, version)){
return singleton;
}
return null;
}
// DOM L3 LS
/**
* DOM Level 3 LS CR - Experimental.
* Create a new LSParser. The newly constructed parser may
* then be configured by means of its DOMConfiguration
* object, and used to parse documents by means of its parse
* method.
* @param mode The mode argument is either
* MODE_SYNCHRONOUS or MODE_ASYNCHRONOUS, if
* mode is MODE_SYNCHRONOUS then the
* LSParser that is created will operate in synchronous
* mode, if it's MODE_ASYNCHRONOUS then the
* LSParser that is created will operate in asynchronous
* mode.
* @param schemaType An absolute URI representing the type of the schema
* language used during the load of a Document using the
* newly created LSParser. Note that no lexical checking
* is done on the absolute URI. In order to create a
* LSParser for any kind of schema types (i.e. the
* LSParser will be free to use any schema found), use the value
* null.
*
Note: For W3C XML Schema [XML Schema Part 1]
* , applications must use the value
* "http://www.w3.org/2001/XMLSchema". For XML DTD [XML 1.0],
* applications must use the value
* "http://www.w3.org/TR/REC-xml". Other Schema languages
* are outside the scope of the W3C and therefore should recommend an
* absolute URI in order to use this method.
* @return The newly created LSParser object. This
* LSParser is either synchronous or asynchronous
* depending on the value of the mode argument.
*
Note: By default, the newly created LSParser
* does not contain a DOMErrorHandler, i.e. the value of
* the "
* error-handler" configuration parameter is null. However, implementations
* may provide a default error handler at creation time. In that case,
* the initial value of the "error-handler" configuration
* parameter on the new created LSParser contains a
* reference to the default error handler.
* @exception DOMException
* NOT_SUPPORTED_ERR: Raised if the requested mode or schema type is
* not supported.
*/
public LSParser createLSParser(short mode, String schemaType)
throws DOMException {
if (mode != DOMImplementationLS.MODE_SYNCHRONOUS || (schemaType !=null &&
!"http://www.w3.org/2001/XMLSchema".equals(schemaType) &&
!"http://www.w3.org/TR/REC-xml".equals(schemaType))) {
String msg =
DOMMessageFormatter.formatMessage(
DOMMessageFormatter.DOM_DOMAIN,
"NOT_SUPPORTED_ERR",
null);
throw new DOMException(DOMException.NOT_SUPPORTED_ERR, msg);
}
if (schemaType != null
&& schemaType.equals("http://www.w3.org/TR/REC-xml")) {
return new DOMParserImpl(
"com.sun.org.apache.xerces.internal.parsers.XML11Configuration",
schemaType);
}
else {
// create default parser configuration validating against XMLSchemas
return new DOMParserImpl(
"com.sun.org.apache.xerces.internal.parsers.XML11Configuration",
schemaType);
}
}
/**
* DOM Level 3 LS CR - Experimental.
* Create a new LSSerializer object.
* @return The newly created LSSerializer object.
*
Note: By default, the newly created
* LSSerializer has no DOMErrorHandler,
* i.e. the value of the "error-handler" configuration
* parameter is null. However, implementations may
* provide a default error handler at creation time. In that case, the
* initial value of the "error-handler" configuration
* parameter on the new created LSSerializer contains a
* reference to the default error handler.
*/
public LSSerializer createLSSerializer() {
return new DOMSerializerImpl();
}
/**
* DOM Level 3 LS CR - Experimental.
* Create a new empty input source.
* @return The newly created input object.
*/
public LSInput createLSInput() {
return new DOMInputImpl();
}
synchronized Object getDTDValidator() {
return ObjectFactory.newInstance( "com.sun.org.apache.xerces.internal.impl.dtd.XMLDTDValidator", ObjectFactory.findClassLoader(), true);
}
//
// Protected methods
//
/** NON-DOM: retrieve validator. */
synchronized RevalidationHandler getValidator(String schemaType) {
// REVISIT: implement retrieving DTD validator
if (freeValidatorIndex < 0) {
// create new validator - we should not attempt
// to restrict the number of validation handlers being
// requested
return (RevalidationHandler) (ObjectFactory .newInstance( "com.sun.org.apache.xerces.internal.impl.xs.XMLSchemaValidator", ObjectFactory.findClassLoader(), true));
}
// return first available validator
RevalidationHandler val = validators[freeValidatorIndex];
validators[freeValidatorIndex--] = null;
return val;
}
/** NON-DOM: release validator */
synchronized void releaseValidator(String schemaType,
RevalidationHandler validator) {
// REVISIT: implement support for DTD validators as well
++freeValidatorIndex;
if (validators.length == freeValidatorIndex ){
// resize size of the validators
currentSize+=SIZE;
RevalidationHandler newarray[] = new RevalidationHandler[currentSize];
System.arraycopy(validators, 0, newarray, 0, validators.length);
validators = newarray;
}
validators[freeValidatorIndex]=validator;
}
/** NON-DOM: increment document/doctype counter */
protected synchronized int assignDocumentNumber() {
return ++docAndDoctypeCounter;
}
/** NON-DOM: increment document/doctype counter */
protected synchronized int assignDocTypeNumber() {
return ++docAndDoctypeCounter;
}
/* DOM Level 3 LS CR - Experimental.
*
* Create a new empty output destination object where
* LSOutput.characterStream,
* LSOutput.byteStream, LSOutput.systemId,
* LSOutput.encoding are null.
* @return The newly created output object.
*/
public LSOutput createLSOutput() {
return new DOMOutputImpl();
}
} // class DOMImplementationImpl