| /* |
| * The Apache Software License, Version 1.1 |
| * |
| * |
| * Copyright (c) 2003 The Apache Software Foundation. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in |
| * the documentation and/or other materials provided with the |
| * distribution. |
| * |
| * 3. The end-user documentation included with the redistribution, |
| * if any, must include the following acknowledgment: |
| * "This product includes software developed by the |
| * Apache Software Foundation (http://www.apache.org/)." |
| * Alternately, this acknowledgment may appear in the software itself, |
| * if and wherever such third-party acknowledgments normally appear. |
| * |
| * 4. The names "Xalan" and "Apache Software Foundation" must |
| * not be used to endorse or promote products derived from this |
| * software without prior written permission. For written |
| * permission, please contact apache@apache.org. |
| * |
| * 5. Products derived from this software may not be called "Apache", |
| * nor may "Apache" appear in their name, without prior written |
| * permission of the Apache Software Foundation. |
| * |
| * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED |
| * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR |
| * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF |
| * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
| * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
| * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
| * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| * SUCH DAMAGE. |
| * ==================================================================== |
| * |
| * This software consists of voluntary contributions made by many |
| * individuals on behalf of the Apache Software Foundation and was |
| * originally based on software copyright (c) 2003, International Business |
| * Machines, Inc., http://www.ibm.com. For more information on the Apache |
| * Software Foundation, please see |
| * <http://www.apache.org/>. |
| */ |
| package org.apache.xml.serializer; |
| |
| import java.util.Enumeration; |
| import java.util.Hashtable; |
| import java.util.Stack; |
| |
| import org.xml.sax.ContentHandler; |
| import org.xml.sax.SAXException; |
| |
| /** |
| * This class keeps track of the currently defined namespaces. Conceptually the |
| * prefix/uri/depth triplets are pushed on a stack pushed on a stack. The depth |
| * indicates the nesting depth of the element for which the mapping was made. |
| * |
| * <p>For example: |
| * <pre> |
| * <chapter xmlns:p1="def"> |
| * <paragraph xmlns:p2="ghi"> |
| * <sentance xmlns:p3="jkl"> |
| * </sentance> |
| * </paragraph> |
| * <paragraph xlmns:p4="mno"> |
| * </paragraph> |
| * </chapter> |
| * </pre> |
| * |
| * When the <chapter> element is encounted the prefix "p1" associated with uri |
| * "def" is pushed on the stack with depth 1. |
| * When the first <paragraph> is encountered "p2" and "ghi" are pushed with |
| * depth 2. |
| * When the <sentance> is encountered "p3" and "jkl" are pushed with depth 3. |
| * When </sentance> occurs the popNamespaces(3) will pop "p3"/"jkl" off the |
| * stack. Of course popNamespaces(2) would pop anything with depth 2 or |
| * greater. |
| * |
| * So prefix/uri pairs are pushed and poped off the stack as elements are |
| * processed. At any given moment of processing the currently visible prefixes |
| * are on the stack and a prefix can be found given a uri, or a uri can be found |
| * given a prefix. |
| */ |
| public class NamespaceMappings |
| { |
| /** |
| * This member is continually incremented when new prefixes need to be |
| * generated. ("ns0" "ns1" ...) |
| */ |
| private int count = 0; |
| |
| /** |
| * Stack of prefixes that have mappings |
| * The top of this stack is the prefix that was last mapped to an URI |
| * |
| * For every prefix pushed on this stack a corresponding integer is pushed |
| * on the m_nodeStack. That way all prefixes pushed at the current depth can |
| * be removed at the same time. |
| */ |
| private java.util.Stack m_prefixStack = new Stack(); |
| |
| /** |
| * Each entry (prefix) in this hashtable points to a Stack of URIs |
| */ |
| private Hashtable m_namespaces = new Hashtable(); |
| |
| /** |
| * The top of this stack contains the nested element depth |
| * of the last declared a namespace. |
| * Used to know how many prefix mappings to pop when leaving |
| * the current element depth. |
| * For every prefix mapping the current element depth is |
| * pushed on this stack, as well as the prefix on the m_prefixStack |
| * That way all prefixes pushed at the current depth can be |
| * removed at the same time. |
| * Used to ensure prefix/uri map scopes are closed correctly |
| * |
| */ |
| private Stack m_nodeStack = new Stack(); |
| |
| private static final String EMPTYSTRING = ""; |
| private static final String XML_PREFIX = "xml"; // was "xmlns" |
| |
| /** |
| * Default constructor |
| * @see java.lang.Object#Object() |
| */ |
| public NamespaceMappings() |
| { |
| initNamespaces(); |
| } |
| |
| /** |
| * This method initializes the namespace object with appropriate stacks |
| * and predefines a few prefix/uri pairs which always exist. |
| */ |
| private void initNamespaces() |
| { |
| |
| |
| // Define the default namespace (initially maps to "" uri) |
| Stack stack; |
| m_namespaces.put(EMPTYSTRING, stack = new Stack()); |
| stack.push(EMPTYSTRING); |
| m_prefixStack.push(EMPTYSTRING); |
| |
| m_namespaces.put(XML_PREFIX, stack = new Stack()); |
| stack.push("http://www.w3.org/XML/1998/namespace"); |
| m_prefixStack.push(XML_PREFIX); |
| |
| m_nodeStack.push(new Integer(-1)); |
| |
| } |
| |
| /** |
| * Use a namespace prefix to lookup a namespace URI. |
| * |
| * @param prefix String the prefix of the namespace |
| * @return the URI corresponding to the prefix |
| */ |
| public String lookupNamespace(String prefix) |
| { |
| final Stack stack = (Stack) m_namespaces.get(prefix); |
| return stack != null && !stack.isEmpty() ? (String) stack.peek() : null; |
| } |
| |
| /** |
| * Given a namespace uri, and the namespaces mappings for the |
| * current element, return the current prefix for that uri. |
| * |
| * @param uri the namespace URI to be search for |
| * @return an existing prefix that maps to the given URI, null if no prefix |
| * maps to the given namespace URI. |
| */ |
| public String lookupPrefix(String uri) |
| { |
| String foundPrefix = null; |
| Enumeration prefixes = m_namespaces.keys(); |
| while (prefixes.hasMoreElements()) |
| { |
| String prefix = (String) prefixes.nextElement(); |
| String uri2 = lookupNamespace(prefix); |
| if (uri2 != null && uri2.equals(uri)) |
| { |
| foundPrefix = prefix; |
| break; |
| } |
| } |
| return foundPrefix; |
| } |
| |
| /** |
| * Undeclare the namespace that is currently pointed to by a given prefix |
| */ |
| public boolean popNamespace(String prefix) |
| { |
| // Prefixes "xml" and "xmlns" cannot be redefined |
| if (prefix.startsWith(XML_PREFIX)) |
| { |
| return false; |
| } |
| |
| Stack stack; |
| if ((stack = (Stack) m_namespaces.get(prefix)) != null) |
| { |
| stack.pop(); |
| return true; |
| } |
| return false; |
| } |
| |
| /** |
| * Declare a prefix to point to a namespace URI |
| * @param prefix a String with the prefix for a qualified name |
| * @param uri a String with the uri to which the prefix is to map |
| * @param elemDepth the depth of current declaration |
| */ |
| public boolean pushNamespace(String prefix, String uri, int elemDepth) |
| { |
| // Prefixes "xml" and "xmlns" cannot be redefined |
| if (prefix.startsWith(XML_PREFIX)) |
| { |
| return false; |
| } |
| |
| Stack stack; |
| // Get the stack that contains URIs for the specified prefix |
| if ((stack = (Stack) m_namespaces.get(prefix)) == null) |
| { |
| m_namespaces.put(prefix, stack = new Stack()); |
| } |
| |
| if (!stack.empty() && uri.equals(stack.peek())) |
| { |
| return false; |
| } |
| |
| stack.push(uri); |
| m_prefixStack.push(prefix); |
| m_nodeStack.push(new Integer(elemDepth)); |
| return true; |
| } |
| |
| /** |
| * Pop, or undeclare all namespace definitions that are currently |
| * declared at the given element depth, or deepter. |
| * @param elemDepth the element depth for which mappings declared at this |
| * depth or deeper will no longer be valid |
| * @param saxHandler The ContentHandler to notify of any endPrefixMapping() |
| * calls. This parameter can be null. |
| */ |
| public void popNamespaces(int elemDepth, ContentHandler saxHandler) |
| { |
| while (true) |
| { |
| if (m_nodeStack.isEmpty()) |
| return; |
| Integer i = (Integer) (m_nodeStack.peek()); |
| if (i.intValue() < elemDepth) |
| return; |
| /* the depth of the declared mapping is elemDepth or deeper |
| * so get rid of it |
| */ |
| |
| m_nodeStack.pop(); |
| final String prefix = (String) m_prefixStack.pop(); |
| popNamespace(prefix); |
| if (saxHandler != null) |
| { |
| try |
| { |
| saxHandler.endPrefixMapping(prefix); |
| } |
| catch (SAXException e) |
| { |
| // not much we can do if they aren't willing to listen |
| } |
| } |
| |
| } |
| } |
| |
| /** |
| * Generate a new namespace prefix ( ns0, ns1 ...) not used before |
| * @return String a new namespace prefix ( ns0, ns1, ns2 ...) |
| */ |
| public String generateNextPrefix() |
| { |
| return "ns" + (count++); |
| } |
| |
| |
| /** |
| * This method makes a clone of this object. |
| * |
| */ |
| public Object clone() throws CloneNotSupportedException { |
| NamespaceMappings clone = new NamespaceMappings(); |
| clone.m_prefixStack = (Stack)m_prefixStack.clone(); |
| clone.m_nodeStack = (Stack) m_nodeStack.clone(); |
| clone.m_namespaces = (Hashtable) m_namespaces.clone(); |
| |
| clone.count = count; |
| return clone; |
| |
| } |
| |
| public final void reset() |
| { |
| this.count = 0; |
| this.m_namespaces.clear(); |
| this.m_nodeStack.clear(); |
| this.m_prefixStack.clear(); |
| |
| initNamespaces(); |
| } |
| |
| } |
