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Commons JXPath example source code file (JDOMNodeIterator.java)
The Commons JXPath JDOMNodeIterator.java source code/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You 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 org.apache.commons.jxpath.ri.model.jdom; import java.util.Collections; import java.util.List; import org.apache.commons.jxpath.ri.compiler.NodeTest; import org.apache.commons.jxpath.ri.model.NodeIterator; import org.apache.commons.jxpath.ri.model.NodePointer; import org.jdom.Document; import org.jdom.Element; /** * An iterator of children of a JDOM Node. * * @author Dmitri Plotnikov * @version $Revision: 652845 $ $Date: 2008-05-02 12:46:46 -0500 (Fri, 02 May 2008) $ */ public class JDOMNodeIterator implements NodeIterator { private NodePointer parent; private NodeTest nodeTest; private boolean reverse; private int position = 0; private int index = 0; private List children; private Object child; /** * Create a new JDOMNodeIterator. * @param parent pointer * @param nodeTest test * @param reverse whether to iterate in reverse * @param startWith starting pointer */ public JDOMNodeIterator( NodePointer parent, NodeTest nodeTest, boolean reverse, NodePointer startWith) { this.parent = parent; if (startWith != null) { this.child = startWith.getNode(); } // TBD: optimize me for different node tests Object node = parent.getNode(); if (node instanceof Document) { this.children = ((Document) node).getContent(); } else if (node instanceof Element) { this.children = ((Element) node).getContent(); } else { this.children = Collections.EMPTY_LIST; } this.nodeTest = nodeTest; this.reverse = reverse; } public NodePointer getNodePointer() { if (child == null) { if (!setPosition(1)) { return null; } position = 0; } return new JDOMNodePointer(parent, child); } public int getPosition() { return position; } public boolean setPosition(int position) { while (this.position < position) { if (!next()) { return false; } } while (this.position > position) { if (!previous()) { return false; } } return true; } /** * This is actually never invoked during the normal evaluation * of xpaths - an iterator is always going forward, never backwards. * So, this is implemented only for completeness and perhaps for * those who use these iterators outside of XPath evaluation. * @return boolean */ private boolean previous() { position--; if (!reverse) { while (--index >= 0) { child = children.get(index); if (testChild()) { return true; } } } else { for (; index < children.size(); index++) { child = children.get(index); if (testChild()) { return true; } } } return false; } /** * Iterate to next pointer. * @return whether valid */ private boolean next() { position++; if (!reverse) { if (position == 1) { index = 0; if (child != null) { index = children.indexOf(child) + 1; } } else { index++; } for (; index < children.size(); index++) { child = children.get(index); if (testChild()) { return true; } } return false; } else { if (position == 1) { index = children.size() - 1; if (child != null) { index = children.indexOf(child) - 1; } } else { index--; } for (; index >= 0; index--) { child = children.get(index); if (testChild()) { return true; } } return false; } } /** * Test a child node. * @return whether test passes. */ private boolean testChild() { return JDOMNodePointer.testNode(parent, child, nodeTest); } } Other Commons JXPath examples (source code examples)Here is a short list of links related to this Commons JXPath JDOMNodeIterator.java source code file: |
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