Mercurial > jdk8-mips64-public > jaxws / file revision

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  * 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

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 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;

     }

 }