coredomimplementationimpl.java

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/*
 * Copyright 1999-2005 The Apache Software Foundation.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.sun.org.apache.xerces.internal.dom;

import com.sun.org.apache.xerces.internal.impl.RevalidationHandler;
import com.sun.org.apache.xerces.internal.parsers.DOMParserImpl;
import com.sun.org.apache.xerces.internal.util.XMLChar;
import com.sun.org.apache.xerces.internal.xni.grammars.XMLGrammarDescription;
import com.sun.org.apache.xml.internal.serialize.DOMSerializerImpl;
import org.w3c.dom.DOMException;
import org.w3c.dom.DOMImplementation;
import org.w3c.dom.Document;
import org.w3c.dom.DocumentType;
import org.w3c.dom.Element;
import org.w3c.dom.ls.LSParser;
import org.w3c.dom.ls.DOMImplementationLS;
import org.w3c.dom.ls.LSInput;
import org.w3c.dom.ls.LSOutput;
import org.w3c.dom.ls.LSSerializer;
/**
 * The DOMImplementation class is description of a particular
 * implementation of the Document Object Model. As such its data is
 * static, shared by all instances of this implementation.
 * <P>
 * 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.
 * <P>
 * 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.
 * 
 * @xerces.internal
 * 
 * @version $Id: CoreDOMImplementationImpl.java,v 1.2.6.1 2005/08/30 14:57:58 sunithareddy 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 RevalidationHandler dtdValidators[] = new RevalidationHandler[SIZE];
    private int freeValidatorIndex = -1;
    private int freeDTDValidatorIndex = -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;
	    
	    // check if Xalan implementation is around and if yes report true for supporting
	    // XPath API
	    // if a plus sign "+" is prepended to any feature name, implementations 
	    // are considered in which the specified feature may not be directly 
	    // castable DOMImplementation.getFeature(feature, version). Without a 
	    // plus, only features whose interfaces are directly castable are considered.
	    if ((feature.equalsIgnoreCase("+XPath"))       
	        && (anyVersion || version.equals("3.0"))) {
	        try {
	            Class xpathClass = ObjectFactory.findProviderClass(
	                "com.sun.org.apache.xpath.internal.domapi.XPathEvaluatorImpl",
	                ObjectFactory.findClassLoader(), true);
                
                // Check if the DOM XPath implementation implements
                // the interface org.w3c.dom.XPathEvaluator
                Class interfaces[] = xpathClass.getInterfaces();
                for (int i = 0; i < interfaces.length; i++) {
                    if (interfaces[i].getName().equals(
                        "org.w3c.dom.xpath.XPathEvaluator")) {
                        return true;
                    }
                }
	        } catch (Exception e) {
	            return false;
	        }
	        return true;
	    }
	    if (feature.startsWith("+")) {
	        feature = feature.substring(1);
	    }
	    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. <p>
	 *
	 * 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. <p>
	 *
	 * 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.<p>