| /* |
| * reserved comment block |
| * DO NOT REMOVE OR ALTER! |
| */ |
| /* |
| * Copyright 2003-2004 The Apache Software Foundation. |
| * |
| * Licensed 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. |
| */ |
| /* |
| * $Id: NamespaceMappings.java,v 1.2.4.1 2005/09/15 08:15:19 suresh_emailid Exp $ |
| */ |
| package com.sun.org.apache.xml.internal.serializer; |
| |
| import java.util.HashMap; |
| import java.util.Iterator; |
| 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. |
| * |
| * This class is public only because it is used by Xalan. It is not a public API |
| * |
| * @xsl.usage internal |
| */ |
| public class NamespaceMappings |
| { |
| /** |
| * This member is continually incremented when new prefixes need to be |
| * generated. ("ns0" "ns1" ...) |
| */ |
| private int count; |
| |
| /** |
| * Each entry (prefix) in this hashmap points to a Stack of URIs |
| * This maps a prefix (String) to a Stack of prefix mappings. |
| * All mappings in that retrieved stack have the same prefix, |
| * though possibly different URI's or depths. Such a stack must have |
| * mappings at deeper depths push later on such a stack. Mappings pushed |
| * earlier on the stack will have smaller values for MappingRecord.m_declarationDepth. |
| */ |
| private HashMap m_namespaces = new HashMap(); |
| |
| /** |
| * The top of this stack contains the MapRecord |
| * 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. |
| * 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(new MappingRecord(EMPTYSTRING,EMPTYSTRING,0)); |
| |
| m_namespaces.put(XML_PREFIX, stack = new Stack()); |
| stack.push(new MappingRecord( XML_PREFIX, |
| "http://www.w3.org/XML/1998/namespace",0)); |
| |
| m_nodeStack.push(new MappingRecord(null,null,-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() ? |
| ((MappingRecord) stack.peek()).m_uri : null; |
| } |
| |
| MappingRecord getMappingFromPrefix(String prefix) { |
| final Stack stack = (Stack) m_namespaces.get(prefix); |
| return stack != null && !stack.isEmpty() ? |
| ((MappingRecord) 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; |
| Iterator<String> itr = m_namespaces.keySet().iterator(); |
| while (itr.hasNext()) { |
| String prefix = itr.next(); |
| String uri2 = lookupNamespace(prefix); |
| if (uri2 != null && uri2.equals(uri)) |
| { |
| foundPrefix = prefix; |
| break; |
| } |
| } |
| return foundPrefix; |
| } |
| |
| MappingRecord getMappingFromURI(String uri) |
| { |
| MappingRecord foundMap = null; |
| Iterator<String> itr = m_namespaces.keySet().iterator(); |
| while (itr.hasNext()) |
| { |
| String prefix = itr.next(); |
| MappingRecord map2 = getMappingFromPrefix(prefix); |
| if (map2 != null && (map2.m_uri).equals(uri)) |
| { |
| foundMap = map2; |
| break; |
| } |
| } |
| return foundMap; |
| } |
| |
| /** |
| * Undeclare the namespace that is currently pointed to by a given prefix |
| */ |
| 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 mapping of a prefix to namespace URI at the given element depth. |
| * @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 |
| */ |
| 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(((MappingRecord)stack.peek()).m_uri)) |
| { |
| return false; |
| } |
| MappingRecord map = new MappingRecord(prefix,uri,elemDepth); |
| stack.push(map); |
| m_nodeStack.push(map); |
| 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. |
| */ |
| void popNamespaces(int elemDepth, ContentHandler saxHandler) |
| { |
| while (true) |
| { |
| if (m_nodeStack.isEmpty()) |
| return; |
| MappingRecord map = (MappingRecord)(m_nodeStack.peek()); |
| int depth = map.m_declarationDepth; |
| if (depth < elemDepth) |
| return; |
| /* the depth of the declared mapping is elemDepth or deeper |
| * so get rid of it |
| */ |
| |
| map = (MappingRecord) m_nodeStack.pop(); |
| final String prefix = map.m_prefix; |
| 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_nodeStack = (Stack) m_nodeStack.clone(); |
| clone.m_namespaces = (HashMap) m_namespaces.clone(); |
| clone.count = count; |
| return clone; |
| |
| } |
| |
| final void reset() |
| { |
| this.count = 0; |
| this.m_namespaces.clear(); |
| this.m_nodeStack.clear(); |
| initNamespaces(); |
| } |
| |
| class MappingRecord { |
| final String m_prefix; // the prefix |
| final String m_uri; // the uri |
| // the depth of the element where declartion was made |
| final int m_declarationDepth; |
| MappingRecord(String prefix, String uri, int depth) { |
| m_prefix = prefix; |
| m_uri = uri; |
| m_declarationDepth = depth; |
| |
| } |
| } |
| |
| } |