groovy-core/src/main/groovy/util/Node.java - groovy - Git at Google

 /*
  * Copyright 2003-2007 the original author or authors.
  *
  * 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.
  */
 package groovy.util;

 import groovy.xml.QName;
 import org.codehaus.groovy.runtime.InvokerHelper;

 import java.io.PrintWriter;
 import java.util.*;

 /**
  * Represents an arbitrary tree node which can be used for structured metadata or any arbitrary XML-like tree.
  * A node can have a name, a value and an optional Map of attributes.
  * Typically the name is a String and a value is either a String or a List of other Nodes,
  * though the types are extensible to provide a flexible structure, e.g. you could use a
  * QName as the name which includes a namespace URI and a local name. Or a JMX ObjectName etc.
  * So this class can represent metadata like {foo a=1 b="abc"} or nested metadata like {foo a=1 b="123" { bar x=12 text="hello" }}
  *
  * @author <a href="mailto:james@coredevelopers.net">James Strachan</a>
  * @version $Revision$
  */
 public class Node implements java.io.Serializable {

     private static final long serialVersionUID = 4121134753270542643L;
     private Node parent;
     private Object name;
     private Map attributes;
     private Object value;

     public Node(Node parent, Object name) {
         this(parent, name, new ArrayList());
     }

     public Node(Node parent, Object name, Object value) {
         this(parent, name, new HashMap(), value);
     }

     public Node(Node parent, Object name, Map attributes) {
         this(parent, name, attributes, new ArrayList());
     }

     public Node(Node parent, Object name, Map attributes, Object value) {
         this.parent = parent;
         this.name = name;
         this.attributes = attributes;
         this.value = value;

         if (parent != null) {
             Object parentValue = parent.value();
             List parentList;
             if (parentValue instanceof List) {
                 parentList = (List) parentValue;
             } else {
                 parentList = new NodeList();
                 parentList.add(parentValue);
                 parent.setValue(parentList);
             }
             parentList.add(this);
         }
     }

     public String text() {
         if (value instanceof String) {
             return (String) value;
         }
         else if (value instanceof Collection) {
             Collection coll = (Collection) value;
             String previousText = null;
             StringBuffer buffer = null;
             for (Iterator iter = coll.iterator(); iter.hasNext();) {
                 Object child = iter.next();
                 if (child instanceof String) {
                     String childText = (String) child;
                     if (previousText == null) {
                         previousText = childText;
                     }
                     else {
                         if (buffer == null) {
                             buffer = new StringBuffer();
                             buffer.append(previousText);
                         }
                         buffer.append(childText);
                     }
                 }
             }
             if (buffer != null) {
                 return buffer.toString();
             }
             else {
                 if (previousText != null) {
                     return previousText;
                 }
             }
         }
         return "";
     }


     public Iterator iterator() {
         return children().iterator();
     }

     public List children() {
         if (value == null) {
             return new ArrayList();
         }
         else if (value instanceof List) {
             return (List) value;
         }
         else {
             // we're probably just a String
             return java.util.Collections.singletonList(value);
         }
     }

     public Map attributes() {
         return attributes;
     }

     public Object attribute(Object key) {
         return (attributes != null) ? attributes.get(key) : null;
     }

     public Object name() {
         return name;
     }

     public Object value() {
         return value;
     }

     public void setValue(Object value) {
         this.value = value;
     }

     public Node parent() {
         return parent;
     }

     /**
      * Provides lookup of elements by non-namespaced name
      * @param key the name (or shortcut key) of the node(s) of interest
      * @return the nodes which match key
      */
     public Object get(String key) {
         if (key != null && key.charAt(0) == '@') {
             String attributeName = key.substring(1);
             return attributes().get(attributeName);
         }
         if ("..".equals(key)) {
             return parent();
         }
         if ("*".equals(key)) {
             return children();
         }
         if ("**".equals(key)) {
             return depthFirst();
         }
         // iterate through list looking for node with name 'key'
         List answer = new NodeList();
         for (Iterator iter = children().iterator(); iter.hasNext();) {
             Object child = iter.next();
             if (child instanceof Node) {
                 Node childNode = (Node) child;
                 Object childNodeName = childNode.name();
                 if (childNodeName != null && childNodeName.equals(key)) {
                     answer.add(childNode);
                 }
             }
         }
         return answer;
     }

     /**
      * Provides lookup of elements by QName.
      *
      * @param name the QName of interest
      * @return the nodes matching name
      */
     public NodeList getAt(QName name) {
         NodeList answer = new NodeList();
         for (Iterator iter = children().iterator(); iter.hasNext();) {
             Object child = iter.next();
             if (child instanceof Node) {
                 Node childNode = (Node) child;
                 Object childNodeName = childNode.name();
                 if (childNodeName != null && childNodeName.equals(name)) {
                     answer.add(childNode);
                 }
             }
         }
         return answer;
     }

     /**
      * Provide a collection of all the nodes in the tree
      * using a depth first traversal.
      *
      * @return the list of (depth-first) ordered nodes
      */
     public List depthFirst() {
         List answer = new NodeList();
         answer.add(this);
         answer.addAll(depthFirstRest());
         return answer;
     }

     private List depthFirstRest() {
         List answer = new NodeList();
         for (Iterator iter = InvokerHelper.asIterator(value); iter.hasNext(); ) {
             Object child = iter.next();
             if (child instanceof Node) {
                 Node childNode = (Node) child;
                 List children = childNode.depthFirstRest();
                 answer.add(childNode);
                 answer.addAll(children);
             }
         }
         return answer;
     }

     /**
      * Provide a collection of all the nodes in the tree
      * using a breadth-first traversal.
      *
      * @return the list of (breadth-first) ordered nodes
      */
     public List breadthFirst() {
         List answer = new NodeList();
         answer.add(this);
         answer.addAll(breadthFirstRest());
         return answer;
     }

     private List breadthFirstRest() {
         List answer = new NodeList();
         List nextLevelChildren = getDirectChildren();
         while (!nextLevelChildren.isEmpty()) {
             List working = new NodeList(nextLevelChildren);
             nextLevelChildren = new NodeList();
             for (Iterator iter = working.iterator(); iter.hasNext(); ) {
                 Node childNode = (Node) iter.next();
                 answer.add(childNode);
                 List children = childNode.getDirectChildren();
                 nextLevelChildren.addAll(children);
             }
         }
         return answer;
     }

     private List getDirectChildren() {
         List answer = new NodeList();
         for (Iterator iter = InvokerHelper.asIterator(value); iter.hasNext(); ) {
             Object child = iter.next();
             if (child instanceof Node) {
                 Node childNode = (Node) child;
                 answer.add(childNode);
             }
         }
         return answer;
     }

     public String toString() {
         return name + "[attributes=" + attributes + "; value=" + value + "]";
     }

     public void print(PrintWriter out) {
         new NodePrinter(out).print(this);
     }
 }
	/*
	* Copyright 2003-2007 the original author or authors.
	*
	* 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.
	*/
	package groovy.util;

	import groovy.xml.QName;
	import org.codehaus.groovy.runtime.InvokerHelper;

	import java.io.PrintWriter;
	import java.util.*;

	/**
	* Represents an arbitrary tree node which can be used for structured metadata or any arbitrary XML-like tree.
	* A node can have a name, a value and an optional Map of attributes.
	* Typically the name is a String and a value is either a String or a List of other Nodes,
	* though the types are extensible to provide a flexible structure, e.g. you could use a
	* QName as the name which includes a namespace URI and a local name. Or a JMX ObjectName etc.
	* So this class can represent metadata like {foo a=1 b="abc"} or nested metadata like {foo a=1 b="123" { bar x=12 text="hello" }}
	*
	* @author <a href="mailto:james@coredevelopers.net">James Strachan</a>
	* @version $Revision$
	*/
	public class Node implements java.io.Serializable {

	private static final long serialVersionUID = 4121134753270542643L;
	private Node parent;
	private Object name;
	private Map attributes;
	private Object value;

	public Node(Node parent, Object name) {
	this(parent, name, new ArrayList());
	}

	public Node(Node parent, Object name, Object value) {
	this(parent, name, new HashMap(), value);
	}

	public Node(Node parent, Object name, Map attributes) {
	this(parent, name, attributes, new ArrayList());
	}

	public Node(Node parent, Object name, Map attributes, Object value) {
	this.parent = parent;
	this.name = name;
	this.attributes = attributes;
	this.value = value;

	if (parent != null) {
	Object parentValue = parent.value();
	List parentList;
	if (parentValue instanceof List) {
	parentList = (List) parentValue;
	} else {
	parentList = new NodeList();
	parentList.add(parentValue);
	parent.setValue(parentList);
	}
	parentList.add(this);
	}
	}

	public String text() {
	if (value instanceof String) {
	return (String) value;
	}
	else if (value instanceof Collection) {
	Collection coll = (Collection) value;
	String previousText = null;
	StringBuffer buffer = null;
	for (Iterator iter = coll.iterator(); iter.hasNext();) {
	Object child = iter.next();
	if (child instanceof String) {
	String childText = (String) child;
	if (previousText == null) {
	previousText = childText;
	}
	else {
	if (buffer == null) {
	buffer = new StringBuffer();
	buffer.append(previousText);
	}
	buffer.append(childText);
	}
	}
	}
	if (buffer != null) {
	return buffer.toString();
	}
	else {
	if (previousText != null) {
	return previousText;
	}
	}
	}
	return "";
	}


	public Iterator iterator() {
	return children().iterator();
	}

	public List children() {
	if (value == null) {
	return new ArrayList();
	}
	else if (value instanceof List) {
	return (List) value;
	}
	else {
	// we're probably just a String
	return java.util.Collections.singletonList(value);
	}
	}

	public Map attributes() {
	return attributes;
	}

	public Object attribute(Object key) {
	return (attributes != null) ? attributes.get(key) : null;
	}

	public Object name() {
	return name;
	}

	public Object value() {
	return value;
	}

	public void setValue(Object value) {
	this.value = value;
	}

	public Node parent() {
	return parent;
	}

	/**
	* Provides lookup of elements by non-namespaced name
	* @param key the name (or shortcut key) of the node(s) of interest
	* @return the nodes which match key
	*/
	public Object get(String key) {
	if (key != null && key.charAt(0) == '@') {
	String attributeName = key.substring(1);
	return attributes().get(attributeName);
	}
	if ("..".equals(key)) {
	return parent();
	}
	if ("*".equals(key)) {
	return children();
	}
	if ("**".equals(key)) {
	return depthFirst();
	}
	// iterate through list looking for node with name 'key'
	List answer = new NodeList();
	for (Iterator iter = children().iterator(); iter.hasNext();) {
	Object child = iter.next();
	if (child instanceof Node) {
	Node childNode = (Node) child;
	Object childNodeName = childNode.name();
	if (childNodeName != null && childNodeName.equals(key)) {
	answer.add(childNode);
	}
	}
	}
	return answer;
	}

	/**
	* Provides lookup of elements by QName.
	*
	* @param name the QName of interest
	* @return the nodes matching name
	*/
	public NodeList getAt(QName name) {
	NodeList answer = new NodeList();
	for (Iterator iter = children().iterator(); iter.hasNext();) {
	Object child = iter.next();
	if (child instanceof Node) {
	Node childNode = (Node) child;
	Object childNodeName = childNode.name();
	if (childNodeName != null && childNodeName.equals(name)) {
	answer.add(childNode);
	}
	}
	}
	return answer;
	}

	/**
	* Provide a collection of all the nodes in the tree
	* using a depth first traversal.
	*
	* @return the list of (depth-first) ordered nodes
	*/
	public List depthFirst() {
	List answer = new NodeList();
	answer.add(this);
	answer.addAll(depthFirstRest());
	return answer;
	}

	private List depthFirstRest() {
	List answer = new NodeList();
	for (Iterator iter = InvokerHelper.asIterator(value); iter.hasNext(); ) {
	Object child = iter.next();
	if (child instanceof Node) {
	Node childNode = (Node) child;
	List children = childNode.depthFirstRest();
	answer.add(childNode);
	answer.addAll(children);
	}
	}
	return answer;
	}

	/**
	* Provide a collection of all the nodes in the tree
	* using a breadth-first traversal.
	*
	* @return the list of (breadth-first) ordered nodes
	*/
	public List breadthFirst() {
	List answer = new NodeList();
	answer.add(this);
	answer.addAll(breadthFirstRest());
	return answer;
	}

	private List breadthFirstRest() {
	List answer = new NodeList();
	List nextLevelChildren = getDirectChildren();
	while (!nextLevelChildren.isEmpty()) {
	List working = new NodeList(nextLevelChildren);
	nextLevelChildren = new NodeList();
	for (Iterator iter = working.iterator(); iter.hasNext(); ) {
	Node childNode = (Node) iter.next();
	answer.add(childNode);
	List children = childNode.getDirectChildren();
	nextLevelChildren.addAll(children);
	}
	}
	return answer;
	}

	private List getDirectChildren() {
	List answer = new NodeList();
	for (Iterator iter = InvokerHelper.asIterator(value); iter.hasNext(); ) {
	Object child = iter.next();
	if (child instanceof Node) {
	Node childNode = (Node) child;
	answer.add(childNode);
	}
	}
	return answer;
	}

	public String toString() {
	return name + "[attributes=" + attributes + "; value=" + value + "]";
	}

	public void print(PrintWriter out) {
	new NodePrinter(out).print(this);
	}
	}