| /* |
| * Copyright (c) 2005, 2012, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package com.sun.xml.internal.stream.buffer.stax; |
| |
| import java.util.ArrayList; |
| import java.util.Collections; |
| import java.util.Iterator; |
| import java.util.List; |
| import com.sun.xml.internal.org.jvnet.staxex.NamespaceContextEx; |
| |
| /** |
| * A helper class for managing the declaration of namespaces. |
| * <p> |
| * A namespace is declared on a namespace context. |
| * Namespace contexts are pushed on and popped off the namespace context stack. |
| * <p> |
| * A declared namespace will be in scope iff the context that it was declared on |
| * has not been popped off the stack. |
| * <p> |
| * When instantiated the namespace stack consists of the root namespace context, |
| * which contains, by default, the "xml" and "xmlns" declarations. |
| * Namespaces may be declarations may be declared on the root context. |
| * The root context cannot be popped but can be reset to contain just the |
| * "xml" and "xmlns" declarations. |
| * <p> |
| * Implementation note: determining the prefix from a namespace URI |
| * (or vice versa) is efficient when there are few namespace |
| * declarations i.e. what is considered to be the case for namespace |
| * declarations in 'average' XML documents. The look up of a namespace URI |
| * given a prefix is performed in O(n) time. The look up of a prefix given |
| * a namespace URI is performed in O(2n) time. |
| * <p> |
| * The implementation does not scale when there are many namespace |
| * declarations. TODO: Use a hash map when there are many namespace |
| * declarations. |
| * |
| * @author Paul.Sandoz@Sun.Com |
| */ |
| final public class NamespaceContexHelper implements NamespaceContextEx { |
| private static int DEFAULT_SIZE = 8; |
| |
| // The prefixes of the namespace declarations |
| private String[] prefixes = new String[DEFAULT_SIZE]; |
| // The URIs of the namespace declarations |
| private String[] namespaceURIs = new String[DEFAULT_SIZE]; |
| // Current position to store the next namespace declaration |
| private int namespacePosition; |
| |
| // The namespace contexts |
| private int[] contexts = new int[DEFAULT_SIZE]; |
| // Current position to store the next namespace context |
| private int contextPosition; |
| |
| /** |
| * Create a new NamespaceContexHelper. |
| * |
| */ |
| public NamespaceContexHelper() { |
| // The default namespace declarations that are always in scope |
| prefixes[0] = "xml"; |
| namespaceURIs[0] = "http://www.w3.org/XML/1998/namespace"; |
| prefixes[1] = "xmlns"; |
| namespaceURIs[1] = "http://www.w3.org/2000/xmlns/"; |
| |
| namespacePosition = 2; |
| } |
| |
| |
| // NamespaceContext interface |
| |
| public String getNamespaceURI(String prefix) { |
| if (prefix == null) throw new IllegalArgumentException(); |
| |
| prefix = prefix.intern(); |
| |
| for (int i = namespacePosition - 1; i >= 0; i--) { |
| final String declaredPrefix = prefixes[i]; |
| if (declaredPrefix == prefix) { |
| return namespaceURIs[i]; |
| } |
| } |
| |
| return ""; |
| } |
| |
| public String getPrefix(String namespaceURI) { |
| if (namespaceURI == null) throw new IllegalArgumentException(); |
| |
| for (int i = namespacePosition - 1; i >= 0; i--) { |
| final String declaredNamespaceURI = namespaceURIs[i]; |
| if (declaredNamespaceURI == namespaceURI || declaredNamespaceURI.equals(namespaceURI)) { |
| final String declaredPrefix = prefixes[i]; |
| |
| // Check if prefix is out of scope |
| for (++i; i < namespacePosition; i++) |
| if (declaredPrefix == prefixes[i]) |
| return null; |
| |
| return declaredPrefix; |
| } |
| } |
| |
| return null; |
| } |
| |
| public Iterator getPrefixes(String namespaceURI) { |
| if (namespaceURI == null) throw new IllegalArgumentException(); |
| |
| List<String> l = new ArrayList<String>(); |
| |
| NAMESPACE_LOOP: for (int i = namespacePosition - 1; i >= 0; i--) { |
| final String declaredNamespaceURI = namespaceURIs[i]; |
| if (declaredNamespaceURI == namespaceURI || declaredNamespaceURI.equals(namespaceURI)) { |
| final String declaredPrefix = prefixes[i]; |
| |
| // Check if prefix is out of scope |
| for (int j = i + 1; j < namespacePosition; j++) |
| if (declaredPrefix == prefixes[j]) |
| continue NAMESPACE_LOOP; |
| |
| l.add(declaredPrefix); |
| } |
| } |
| |
| return l.iterator(); |
| } |
| |
| // NamespaceContextEx interface |
| |
| public Iterator<NamespaceContextEx.Binding> iterator() { |
| if (namespacePosition == 2) |
| return Collections.EMPTY_LIST.iterator(); |
| |
| final List<NamespaceContextEx.Binding> namespaces = |
| new ArrayList<NamespaceContextEx.Binding>(namespacePosition); |
| |
| NAMESPACE_LOOP: for (int i = namespacePosition - 1; i >= 2; i--) { |
| final String declaredPrefix = prefixes[i]; |
| |
| // Check if prefix is out of scope |
| for (int j = i + 1; j < namespacePosition; j++) { |
| if (declaredPrefix == prefixes[j]) |
| continue NAMESPACE_LOOP; |
| |
| namespaces.add(new NamespaceBindingImpl(i)); |
| } |
| } |
| |
| return namespaces.iterator(); |
| } |
| |
| final private class NamespaceBindingImpl implements NamespaceContextEx.Binding { |
| int index; |
| |
| NamespaceBindingImpl(int index) { |
| this.index = index; |
| } |
| |
| public String getPrefix() { |
| return prefixes[index]; |
| } |
| |
| public String getNamespaceURI() { |
| return namespaceURIs[index]; |
| } |
| } |
| |
| /** |
| * Declare a default namespace. |
| * <p> |
| * @param namespaceURI the namespace URI to declare, may be null. |
| */ |
| public void declareDefaultNamespace(String namespaceURI) { |
| declareNamespace("", namespaceURI); |
| } |
| |
| /** |
| * Declare a namespace. |
| * <p> |
| * The namespace will be declared on the current namespace context. |
| * <p> |
| * The namespace can be removed by popping the current namespace |
| * context, or, if the declaration occured in the root context, by |
| * reseting the namespace context. |
| * <p> |
| * A default namespace can be declared by passing <code>""</code> as |
| * the value of the prefix parameter. |
| * A namespace may be undeclared by passing <code>null</code> as the |
| * value of the namespaceURI parameter. |
| * <p> |
| * @param prefix the namespace prefix to declare, may not be null. |
| * @param namespaceURI the namespace URI to declare, may be null. |
| * @throws IllegalArgumentException, if the prefix is null. |
| */ |
| public void declareNamespace(String prefix, String namespaceURI) { |
| if (prefix == null) throw new IllegalArgumentException(); |
| |
| prefix = prefix.intern(); |
| // Ignore the "xml" or "xmlns" declarations |
| if (prefix == "xml" || prefix == "xmlns") |
| return; |
| |
| // Check for undeclaration |
| if (namespaceURI != null) |
| namespaceURI = namespaceURI.intern(); |
| |
| if (namespacePosition == namespaceURIs.length) |
| resizeNamespaces(); |
| |
| // Add new declaration |
| prefixes[namespacePosition] = prefix; |
| namespaceURIs[namespacePosition++] = namespaceURI; |
| } |
| |
| private void resizeNamespaces() { |
| final int newLength = namespaceURIs.length * 3 / 2 + 1; |
| |
| String[] newPrefixes = new String[newLength]; |
| System.arraycopy(prefixes, 0, newPrefixes, 0, prefixes.length); |
| prefixes = newPrefixes; |
| |
| String[] newNamespaceURIs = new String[newLength]; |
| System.arraycopy(namespaceURIs, 0, newNamespaceURIs, 0, namespaceURIs.length); |
| namespaceURIs = newNamespaceURIs; |
| } |
| |
| /** |
| * Push a namespace context on the stack. |
| */ |
| public void pushContext() { |
| if (contextPosition == contexts.length) |
| resizeContexts(); |
| |
| contexts[contextPosition++] = namespacePosition; |
| } |
| |
| private void resizeContexts() { |
| int[] newContexts = new int[contexts.length * 3 / 2 + 1]; |
| System.arraycopy(contexts, 0, newContexts, 0, contexts.length); |
| contexts = newContexts; |
| } |
| |
| /** |
| * Pop the namespace context off the stack. |
| * <p> |
| * Namespaces declared within the context (to be popped) |
| * will be removed and no longer be in scope. |
| */ |
| public void popContext() { |
| if (contextPosition > 0) { |
| namespacePosition = contexts[--contextPosition]; |
| } |
| } |
| |
| /** |
| * Reset namespace contexts. |
| * <p> |
| * Pop all namespace contexts and reset the root context. |
| */ |
| public void resetContexts() { |
| namespacePosition = 2; |
| } |
| } |