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Diffstat (limited to 'branches/sca-java-2.0-M4/modules/common-xml/src/main/java/org/apache/tuscany/sca/common/xml/stax/reader/XmlNodeIterator.java')
-rw-r--r-- | branches/sca-java-2.0-M4/modules/common-xml/src/main/java/org/apache/tuscany/sca/common/xml/stax/reader/XmlNodeIterator.java | 258 |
1 files changed, 258 insertions, 0 deletions
diff --git a/branches/sca-java-2.0-M4/modules/common-xml/src/main/java/org/apache/tuscany/sca/common/xml/stax/reader/XmlNodeIterator.java b/branches/sca-java-2.0-M4/modules/common-xml/src/main/java/org/apache/tuscany/sca/common/xml/stax/reader/XmlNodeIterator.java new file mode 100644 index 0000000000..e0eba9a35d --- /dev/null +++ b/branches/sca-java-2.0-M4/modules/common-xml/src/main/java/org/apache/tuscany/sca/common/xml/stax/reader/XmlNodeIterator.java @@ -0,0 +1,258 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you 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. + */ + +package org.apache.tuscany.sca.common.xml.stax.reader; + +import java.util.ArrayList; +import java.util.EmptyStackException; +import java.util.Iterator; +import java.util.List; +import java.util.Map; + +import javax.xml.namespace.NamespaceContext; + +/** + * @version $Rev$ $Date$ + */ +public class XmlNodeIterator implements Iterator<XmlNode> { + public static final int START = 0; + public static final int END = 1; + + protected FastStack<ElementHolder> stack; + protected int state; + protected NamespaceContextImpl nsContext; + + public XmlNodeIterator(XmlNode rootNode) { + super(); + List<XmlNode> v = new ArrayList<XmlNode>(1); + v.add(rootNode); + stack = new FastStack<ElementHolder>(); + Iterator<XmlNode> i = v.iterator(); + stack.push(new ElementHolder(null, i)); + this.state = START; + this.nsContext = new NamespaceContextImpl(null); + } + + public boolean hasNext() { + return !(stack.empty() || (state == END && stack.peek().parent == null)); + } + + public XmlNode next() { + this.state = START; + ElementHolder element = stack.peek(); + Iterator<XmlNode> it = element.children; + if (it == null || (!it.hasNext())) { + // End of the children, return END event of parent + stack.pop(); + this.state = END; + this.nsContext = (NamespaceContextImpl)nsContext.getParent(); + return element.parent; + } + XmlNode node = it.next(); + stack.push(new ElementHolder(node, node.children())); + this.nsContext = new NamespaceContextImpl(this.nsContext); + populateNamespaces(node); + return node; + } + + public void remove() { + throw new UnsupportedOperationException(); + } + + public int getState() { + return state; + } + + public NamespaceContext getNamespaceContext() { + return nsContext; + } + + private void populateNamespaces(XmlNode element) { + if (element.getName() != null) { + if (element.namespaces() != null) { + for (Map.Entry<String, String> e : element.namespaces().entrySet()) { + nsContext.register(e.getKey(), e.getValue()); + } + } + } + } + + private static class ElementHolder { + private XmlNode parent; + private Iterator<XmlNode> children; + + public ElementHolder(XmlNode parent, Iterator<XmlNode> children) { + this.parent = parent; + this.children = children; + } + } + + /** + * An implementation of the {@link java.util.Stack} API that is based on an <code>ArrayList</code> instead of a + * <code>Vector</code>, so it is not synchronized to protect against multi-threaded access. The implementation is + * therefore operates faster in environments where you do not need to worry about multiple thread contention. + * <p> + * The removal order of an <code>ArrayStack</code> is based on insertion order: The most recently added element is + * removed first. The iteration order is <i>not</i> the same as the removal order. The iterator returns elements + * from the bottom up, whereas the {@link #remove()} method removes them from the top down. + * <p> + * Unlike <code>Stack</code>, <code>ArrayStack</code> accepts null entries. + */ + public static class FastStack<T> extends ArrayList<T> { + + /** Ensure Serialization compatibility */ + private static final long serialVersionUID = 2130079159931574599L; + + /** + * Constructs a new empty <code>ArrayStack</code>. The initial size is controlled by <code>ArrayList</code> + * and is currently 10. + */ + public FastStack() { + super(); + } + + /** + * Constructs a new empty <code>ArrayStack</code> with an initial size. + * + * @param initialSize the initial size to use + * @throws IllegalArgumentException if the specified initial size is negative + */ + public FastStack(int initialSize) { + super(initialSize); + } + + /** + * Return <code>true</code> if this stack is currently empty. + * <p> + * This method exists for compatibility with <code>java.util.Stack</code>. New users of this class should use + * <code>isEmpty</code> instead. + * + * @return true if the stack is currently empty + */ + public boolean empty() { + return isEmpty(); + } + + /** + * Returns the top item off of this stack without removing it. + * + * @return the top item on the stack + * @throws EmptyStackException if the stack is empty + */ + public T peek() throws EmptyStackException { + int n = size(); + if (n <= 0) { + throw new EmptyStackException(); + } else { + return get(n - 1); + } + } + + /** + * Returns the n'th item down (zero-relative) from the top of this stack without removing it. + * + * @param n the number of items down to go + * @return the n'th item on the stack, zero relative + * @throws EmptyStackException if there are not enough items on the stack to satisfy this request + */ + public T peek(int n) throws EmptyStackException { + int m = (size() - n) - 1; + if (m < 0) { + throw new EmptyStackException(); + } else { + return get(m); + } + } + + /** + * Pops the top item off of this stack and return it. + * + * @return the top item on the stack + * @throws EmptyStackException if the stack is empty + */ + public T pop() throws EmptyStackException { + int n = size(); + if (n <= 0) { + throw new EmptyStackException(); + } else { + return remove(n - 1); + } + } + + /** + * Pushes a new item onto the top of this stack. The pushed item is also returned. This is equivalent to calling + * <code>add</code>. + * + * @param item the item to be added + * @return the item just pushed + */ + public Object push(T item) { + add(item); + return item; + } + + /** + * Returns the top-most index for the object in the stack + * + * @param object the object to be searched for + * @return top-most index, or -1 if not found + */ + public int search(T object) { + int i = size() - 1; // Current index + while (i >= 0) { + T current = get(i); + if ((object == null && current == null) || (object != null && object.equals(current))) { + return i; + } + i--; + } + return -1; + } + + /** + * Returns the element on the top of the stack. + * + * @return the element on the top of the stack + * @throws EmptyStackException if the stack is empty + */ + public T get() { + int size = size(); + if (size == 0) { + throw new EmptyStackException(); + } + return get(size - 1); + } + + /** + * Removes the element on the top of the stack. + * + * @return the removed element + * @throws EmptyStackException if the stack is empty + */ + public T remove() { + int size = size(); + if (size == 0) { + throw new EmptyStackException(); + } + return remove(size - 1); + } + + } + +} |