1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149
/* * Copyright 2005 Sun Microsystems, Inc. All rights reserved. */ /* * $Id: DOMSubTreeData.java,v 1.2 2005/09/15 14:29:04 mullan Exp $ */ package org.jcp.xml.dsig.internal.dom; import javax.xml.crypto.NodeSetData; import java.util.ArrayList; import java.util.Iterator; import java.util.List; import java.util.ListIterator; import java.util.NoSuchElementException; import org.w3c.dom.NamedNodeMap; import org.w3c.dom.Node; /** * This is a subtype of NodeSetData that represents a dereferenced * same-document URI as the root of a subdocument. The main reason is * for efficiency and performance, as some transforms can operate * directly on the subdocument and there is no need to convert it * first to an XPath node-set. */ public class DOMSubTreeData implements NodeSetData { private boolean excludeComments; private Iterator ni; private Node root; public DOMSubTreeData(Node root, boolean excludeComments) { this.root = root; this.ni = new DelayedNodeIterator(root, excludeComments); this.excludeComments = excludeComments; } public Iterator iterator() { return ni; } public Node getRoot() { return root; } public boolean excludeComments() { return excludeComments; } /** * This is an Iterator that contains a backing node-set that is * not populated until the caller first attempts to advance the iterator. */ static class DelayedNodeIterator implements Iterator { private Node root; private List nodeSet; private ListIterator li; private boolean withComments; DelayedNodeIterator(Node root, boolean excludeComments) { this.root = root; this.withComments = !excludeComments; } public boolean hasNext() { if (nodeSet == null) { nodeSet = dereferenceSameDocumentURI(root); li = nodeSet.listIterator(); } return li.hasNext(); } public Object next() { if (nodeSet == null) { nodeSet = dereferenceSameDocumentURI(root); li = nodeSet.listIterator(); } if (li.hasNext()) { return (Node) li.next(); } else { throw new NoSuchElementException(); } } public void remove() { throw new UnsupportedOperationException(); } /** * Dereferences a same-document URI fragment. * * @param node the node (document or element) referenced by the * URI fragment. If null, returns an empty set. * @return a set of nodes (minus any comment nodes) */ private List dereferenceSameDocumentURI(Node node) { List nodeSet = new ArrayList(); if (node != null) { nodeSetMinusCommentNodes(node, nodeSet, null); } return nodeSet; } /** * Recursively traverses the subtree, and returns an XPath-equivalent * node-set of all nodes traversed, excluding any comment nodes, * if specified. * * @param node the node to traverse * @param nodeSet the set of nodes traversed so far * @param the previous sibling node */ private void nodeSetMinusCommentNodes(Node node, List nodeSet, Node prevSibling) { switch (node.getNodeType()) { case Node.ELEMENT_NODE : NamedNodeMap attrs = node.getAttributes(); if (attrs != null) { for (int i = 0, len = attrs.getLength(); i < len; i++) { nodeSet.add(attrs.item(i)); } } nodeSet.add(node); case Node.DOCUMENT_NODE : Node pSibling = null; for (Node child = node.getFirstChild(); child != null; child = child.getNextSibling()) { nodeSetMinusCommentNodes(child, nodeSet, pSibling); pSibling = child; } break; case Node.TEXT_NODE : case Node.CDATA_SECTION_NODE: // emulate XPath which only returns the first node in // contiguous text/cdata nodes if (prevSibling != null && (prevSibling.getNodeType() == Node.TEXT_NODE || prevSibling.getNodeType() == Node.CDATA_SECTION_NODE)){ return; } case Node.PROCESSING_INSTRUCTION_NODE : nodeSet.add(node); break; case Node.COMMENT_NODE: if (withComments) { nodeSet.add(node); } } } } }