documentnavigator.java

XML的解析、编译、查询等技术的JAVA源代码。

    }

    public Iterator getParentAxisIterator(Object contextNode)
    {
        Object parent = null;

        if ( contextNode instanceof Document )
        {
            return JaxenConstants.EMPTY_ITERATOR;
        }
        else if ( contextNode instanceof Element )
        {
            parent = ((Element)contextNode).getParent();

            if ( parent == null )
            {
                if ( ((Element)contextNode).isRootElement() )
                {
                    parent = ((Element)contextNode).getDocument();
                }
            }
        }
        else if ( contextNode instanceof Attribute )
        {
            parent = ((Attribute)contextNode).getParent();
        }
        else if ( contextNode instanceof XPathNamespace )
        {
            parent = ((XPathNamespace)contextNode).getJDOMElement();
        }
        else if ( contextNode instanceof ProcessingInstruction )
        {
            parent = ((ProcessingInstruction)contextNode).getParent();
        }
        else if ( contextNode instanceof Comment )
        {
            parent = ((Comment)contextNode).getParent();
        }
        else if ( contextNode instanceof Text )
        {
            parent = ((Text)contextNode).getParent();
        }
        
        if ( parent != null )
        {
            return new SingleObjectIterator( parent );
        }

        return JaxenConstants.EMPTY_ITERATOR;
    }

    public Iterator getAttributeAxisIterator(Object contextNode)
    {
        if ( ! ( contextNode instanceof Element ) )
        {
            return JaxenConstants.EMPTY_ITERATOR;
        }

        Element elem = (Element) contextNode;

        return elem.getAttributes().iterator();
    }

    /**
     * Retrieves an <code>Iterator</code> over the attribute elements that
     * match the supplied name.
     *
     * @param contextNode      the origin context node
     * @param localName        the local name of the attributes to return, always present
     * @param namespacePrefix  the prefix of the namespace of the attributes to return
     * @param namespaceURI     the URI of the namespace of the attributes to return
     * @return an Iterator     that traverses the named attributes, not null
     */
    public Iterator getAttributeAxisIterator(
            Object contextNode, String localName, String namespacePrefix, String namespaceURI) {

        if ( contextNode instanceof Element ) {
            Element node = (Element) contextNode;
            Namespace namespace = (namespaceURI == null ? Namespace.NO_NAMESPACE : 
                                    Namespace.getNamespace(namespacePrefix, namespaceURI));
            Attribute attr = node.getAttribute(localName, namespace);
            if (attr != null) {
                return new SingleObjectIterator(attr);
            }
        }
        return JaxenConstants.EMPTY_ITERATOR;
    }

    /** Returns a parsed form of the given XPath string, which will be suitable
     *  for queries on JDOM documents.
     */
    public XPath parseXPath (String xpath) throws SAXPathException
    {
        return new JDOMXPath(xpath);
    }

    public Object getDocumentNode(Object contextNode)
    {
        if ( contextNode instanceof Document )
        {
            return contextNode;
        }

        Element elem = (Element) contextNode;

        return elem.getDocument();
    }

    public String getElementQName(Object obj)
    {
        Element elem = (Element) obj;

        String prefix = elem.getNamespacePrefix();

        if ( prefix == null || prefix.length() == 0 )
        {
            return elem.getName();
        }

        return prefix + ":" + elem.getName();
    }

    public String getAttributeQName(Object obj)
    {
        Attribute attr = (Attribute) obj;

        String prefix = attr.getNamespacePrefix();

        if ( prefix == null || "".equals( prefix ) )
        {
            return attr.getName();
        }

        return prefix + ":" + attr.getName();
    }

    public String getNamespaceStringValue(Object obj)
    {
        if (obj instanceof Namespace) {

            Namespace ns = (Namespace) obj;
            return ns.getURI();
        } else {

            XPathNamespace ns = (XPathNamespace) obj;
            return ns.getJDOMNamespace().getURI();
        }
        
    }

    public String getNamespacePrefix(Object obj)
    {
        if (obj instanceof Namespace) {

            Namespace ns = (Namespace) obj;
            return ns.getPrefix();
        } else {

            XPathNamespace ns = (XPathNamespace) obj;
            return ns.getJDOMNamespace().getPrefix();
        }
    }

    public String getTextStringValue(Object obj)
    {
        if ( obj instanceof Text )
        {
            return ((Text)obj).getText();
        }

        if ( obj instanceof CDATA )
        {
            return ((CDATA)obj).getText();
        }

        return "";
    }

    public String getAttributeStringValue(Object obj)
    {
        Attribute attr = (Attribute) obj;

        return attr.getValue();
    }

    public String getElementStringValue(Object obj)
    {
        Element elem = (Element) obj;

        StringBuffer buf = new StringBuffer();

        List     content     = elem.getContent();
        Iterator contentIter = content.iterator();
        Object   each        = null;

        while ( contentIter.hasNext() )
        {
            each = contentIter.next();

            if ( each instanceof Text )
            {
                buf.append( ((Text)each).getText() );
            }
            else if ( each instanceof CDATA )
            {
                buf.append( ((CDATA)each).getText() );
            }
            else if ( each instanceof Element )
            {
                buf.append( getElementStringValue( each ) );
            }
        }

        return buf.toString();
    }

    public String getProcessingInstructionTarget(Object obj)
    {
        ProcessingInstruction pi = (ProcessingInstruction) obj;

        return pi.getTarget();
    }

    public String getProcessingInstructionData(Object obj)
    {
        ProcessingInstruction pi = (ProcessingInstruction) obj;

        return pi.getData();
    }

    public String getCommentStringValue(Object obj)
    {
        Comment cmt = (Comment) obj;

        return cmt.getText();
    }

    public String translateNamespacePrefixToUri(String prefix, Object context)
    {
        Element element = null;
        if ( context instanceof Element ) 
        {
            element = (Element) context;
        }
        else if ( context instanceof Text )
        {
            element = (Element)((Text)context).getParent();
        }
        else if ( context instanceof Attribute )
        {
            element = ((Attribute)context).getParent();
        }
        else if ( context instanceof XPathNamespace )
        {
            element = ((XPathNamespace)context).getJDOMElement();
        }
        else if ( context instanceof Comment )
        {
            element = (Element)((Comment)context).getParent();
        }
        else if ( context instanceof ProcessingInstruction )
        {
            element = (Element)((ProcessingInstruction)context).getParent();
        }

        if ( element != null )
        {
            Namespace namespace = element.getNamespace( prefix );

            if ( namespace != null ) 
            {
                return namespace.getURI();
            }
        }
        return null;
    }

    public Object getDocument(String url) throws FunctionCallException
    {
        try
        {
            SAXBuilder builder = new SAXBuilder();
            
            return builder.build( url );
        }
        catch (Exception e)
        {
            throw new FunctionCallException( e.getMessage() );
        }
    }
}