nodefilterlocator.java

用Java写的面相对象的数据库管理系统

                                subQueryResults = addNode( subQueryResults, pos );
                            } 
                        } 
                    } 
                    Node nextNode = pos.getFirstChild();
                    while (null == nextNode) {
                        if (context.equals( pos )) {
                            break;
                        } 
                        nextNode = pos.getNextSibling();
                        if (null == nextNode) {
                            pos = pos.getParentNode();
                            if (context.equals( pos ) || pos == null) {
                                nextNode = null;
                                break;
                            } 
                        } 
                    } 
                    pos = nextNode;
                } 
            } 
        } 
        return subQueryResults;
    
    } 
    
    
    /** need overwrite this method, to call traversal methods */
    protected MutableNodeList findFollowing( XPath xpath, XPathSupport execContext, Node context, int opPos,
            int stepType, MutableNodeList subQueryResults, boolean isSimpleFollowing, boolean stopAtFirst ) 
            throws org.xml.sax.SAXException {
        
        System.out.println( "findFollowing()" );
        
        int argLen = xpath.getArgLengthOfStep( opPos );
        opPos = xpath.getFirstChildPosOfStep( opPos );
        
        // What fun...
        Document doc = context.getOwnerDocument();
        
        // DOM2-Traversal
        // save the current walker node!
        Node savedNode = walker.getCurrentNode();
        Node pos = savedNode;
        
        while (null != pos) {
            Node nextNode;
            if (pos != context) {
                if (XPath.MATCH_SCORE_NONE != nodeTest( xpath, execContext, pos, opPos, argLen, stepType )) {
                    subQueryResults = addNodeInDocOrder( execContext, subQueryResults, pos );
                } 
                // DOM2-Traversal
                nextNode = walker.firstChild();
            } else {
                nextNode = null;
            } 
            while (null == nextNode) {
                // DOM2-Traversal
                nextNode = walker.nextSibling();
                if (null == nextNode) {
                    // DOM2-Traversal
                    pos = walker.parentNode();
                    if (doc == pos || null == pos) {
                        nextNode = null;
                        break;
                    } 
                } 
            } 
            pos = nextNode;
        } 
        
        // DOM2-Traversal
        // reset the current walker node!
        walker.setCurrentNode( savedNode );
        return subQueryResults;
    } 
    
    
    /** need overwrite this method, to call traversal methods */
    protected MutableNodeList findFollowingSiblings( XPath xpath, XPathSupport execContext, Node context, int opPos,
            int stepType, MutableNodeList subQueryResults, boolean isSimpleFollowing, boolean stopAtFirst ) 
            throws org.xml.sax.SAXException {
        
        System.out.println( "NodeFilterLocator.findFollowinSiblings ()" );
        
        int argLen = xpath.getArgLengthOfStep( opPos );
        opPos = xpath.getFirstChildPosOfStep( opPos );
        
        // DOM2-Traversal
        // save the current walker node!
        Node savedNode = walker.getCurrentNode();
        Node pos = walker.nextSibling();
        
        while (null != pos) {
            if (XPath.MATCH_SCORE_NONE != nodeTest( xpath, execContext, pos, opPos, argLen, stepType )) {
                subQueryResults = addNode( subQueryResults, pos );
            } 
            // DOM2-Traversal
            pos = walker.nextSibling();
        } 
        // DOM2-Traversal
        // reset the current walker node!
        walker.setCurrentNode( savedNode );
        return subQueryResults;
    } 
    
    
    /** need overwrite this method, to call traversal methods */
    protected MutableNodeList findPreceding( XPath xpath, XPathSupport execContext, Node context, int opPos,
            int stepType, MutableNodeList subQueryResults, boolean isSimpleFollowing, boolean stopAtFirst ) 
            throws org.xml.sax.SAXException {
        
        System.out.println( "findPreceding()" );
        
        return super.findPreceding( xpath, execContext, context, opPos, stepType, subQueryResults, isSimpleFollowing,
                stopAtFirst );
    
    } 
    
    
    /** need overwrite this method, to call traversal methods */
    protected MutableNodeList findPrecedingSiblings( XPath xpath, XPathSupport execContext, Node context, int opPos,
            int stepType, MutableNodeList subQueryResults, boolean isSimpleFollowing, boolean stopAtFirst ) 
            throws org.xml.sax.SAXException {
        
        System.out.println( "findPrecedingSiblings()" );
        
        int argLen = xpath.getArgLengthOfStep( opPos );
        opPos = xpath.getFirstChildPosOfStep( opPos );
        
        // DOM2-Traversal
        // save the current walker node!
        Node savedNode = walker.getCurrentNode();
        Node pos = walker.previousSibling();
        
        while (null != pos) {
            if (XPath.MATCH_SCORE_NONE != nodeTest( xpath, execContext, pos, opPos, argLen, stepType )) {
                subQueryResults = addNode( subQueryResults, pos );
            } 
            // DOM2-Traversal
            pos = walker.previousSibling();
        } 
        
        // DOM2-Traversal
        // reset the current walker node!
        walker.setCurrentNode( savedNode );
        return subQueryResults;
    } 
    
    
    /** need overwrite this method, to call traversal methods */
    protected Node stepPattern( XPath xpath, XPathSupport execContext, Node context, int opPos, double[] scoreHolder ) 
            throws org.xml.sax.SAXException {
        
        System.out.println( "stepPattern()" );
        
        return super.stepPattern( xpath, execContext, context, opPos, scoreHolder );
    } 
    
    
    /** need to implement this method again, b/c its private in my super class */
    private final MutableNodeList addNode( MutableNodeList subQueryResults, Node node ) {
        if (null == subQueryResults) {
            subQueryResults = new MutableNodeListImpl( node );
        } else {
            subQueryResults.addNode( node );
        } 
        return subQueryResults;
    } 
    
    
    /** need to implement this method again, b/c its private in my super class */
    private final MutableNodeList addNodeInDocOrder( XPathSupport execContext, MutableNodeList subQueryResults,
            Node node ) {
        if (null == subQueryResults) {
            subQueryResults = new MutableNodeListImpl( node );
        } else {
            subQueryResults.addNodeInDocOrder( node, execContext );
        } 
        return subQueryResults;
    } 
    
}


/** Override the createXLocatorHandler method. */
class FilterXPath extends XPath {
    
    
    public FilterXPath() {
        super( new org.apache.xalan.xpath.xml.ProblemListenerDefault() );
    }
    
    
    public XLocator createXLocatorHandler( XPath xpath ) {
        return new NodeFilterLocator();
    } 
}


/** Implement an XPath factory. */
class NodeFilterLocatorFactory extends java.lang.Object implements XPathFactory {
    
    
    public XPath create() {
        return new FilterXPath();
    } 
}