import com.sun.org.apache.xerces.internal.dom.EntityReferenceImpl; //导入依赖的package包/类
/**
 * Record baseURI information for the Element (by adding xml:base attribute)
 * or for the ProcessingInstruction (by setting a baseURI field)
 * Non deferred DOM.
 *
 * @param node
 */
protected final void handleBaseURI (Node node){
    if (fDocumentImpl != null) {
        // REVISIT: remove dependency on our implementation when
        //          DOM L3 becomes REC

        String baseURI = null;
        short nodeType = node.getNodeType ();

        if (nodeType == Node.ELEMENT_NODE) {
            // if an element already has xml:base attribute
            // do nothing
            if (fNamespaceAware) {
                if (((Element)node).getAttributeNodeNS ("http://www.w3.org/XML/1998/namespace","base")!=null) {
                    return;
                }
            } else if (((Element)node).getAttributeNode ("xml:base") != null) {
                return;
            }
            // retrive the baseURI from the entity reference
            baseURI = ((EntityReferenceImpl)fCurrentNode).getBaseURI ();
            if (baseURI !=null && !baseURI.equals (fDocumentImpl.getDocumentURI ())) {
                if (fNamespaceAware) {
                    ((Element)node).setAttributeNS ("http://www.w3.org/XML/1998/namespace", "xml:base", baseURI);
                } else {
                    ((Element)node).setAttribute ("xml:base", baseURI);
                }
            }
        }
        else if (nodeType == Node.PROCESSING_INSTRUCTION_NODE) {

            baseURI = ((EntityReferenceImpl)fCurrentNode).getBaseURI ();
            if (baseURI !=null && fErrorHandler != null) {
                DOMErrorImpl error = new DOMErrorImpl ();
                error.fType = "pi-base-uri-not-preserved";
                error.fRelatedData = baseURI;
                error.fSeverity = DOMError.SEVERITY_WARNING;
                fErrorHandler.getErrorHandler ().handleError (error);
            }
        }
    }
}