searchelement.java

数据仓库工具

/*
    Copyright (C) 2003  Together

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library 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
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

package org.enhydra.xml;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

//import org.apache.xerces.parsers.DOMParser;
import org.w3c.dom.DOMException;
import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.w3c.dom.Element;
import org.xml.sax.SAXException;

/**
 * @author Tweety
 *
 * A class representing a node in a meta-data tree, which implements
 * the <a href="../../../../api/org/w3c/dom/Element.html">
 *
 * <p> Namespaces are ignored in this implementation.  The terms "tag
 * name" and "node name" are always considered to be synonymous.
 *
 * @version 1.0
 */
public class SearchElement extends HashMapElement {

	public static String TAG_SEPARATOR = "/";
	public static String ATTR_SEPARATOR = "@";
	public static String EQUAL_SEPARATOR = "=";

	/**
	 * Constructs an empty <code>SearchElement</code>.
	 */
	public SearchElement() {
	}

	/**
	 * Constructs an <code>SearchElement</code> with a given document owner and node name.
	 *
	 * @param ownerDoc the document owner of the node, as a <code>Document</code>.
	 * @param name the name of the node, as a <code>String</code>.
	 */
	public SearchElement(Document ownerDoc, String name) {
		super(ownerDoc, name);
	}

	/**
	 * Constructs an <code>SearchElement</code> with a given <code>Node</code>.
	 *
	 * @param node <code>Node</code>.
	 */
	public SearchElement(Node node) {
		super(node);
	}

	/**
	 * Constructs an <code>SearchElement</code> with a given <code>SearchElement</code>.
	 *
	 * @param node <code>SearchElement</code>.
	 */
	public SearchElement(SearchElement node) {
		super((HashMapElement) node);
	}

	/**
	 * @return new <code>SearchElement</code> instance from a given <code>Node</code>.
	 *
	 * @param node <code>Node</code>.
	 */
	protected Node newElementInstance(Node node) {
		return new SearchElement(node);
	}

  /**
	 * Creates new instance of <code>SearchElement</code> from a given document
	 * as a <code>Document</code>.
	 *
	 * @param document document.
	 *
	 * @return new <code>SearchElement</code> node as a root of the <code>Document</code>.
	 */
	public static Element newInstance(Document document) {
		Node root = document.getDocumentElement();
		return new SearchElement(root);
	}

	/**
	 * Returns a list of elements in the subtree of this node, with the given tag name.
	 *
	 * @param namePath relative path to the </code>Element</code> (through children).
	 *
	 * @return list of elements in the subtree of this node, with the given tag name.
	 */
	public NodeList getSubElementsByTagName(String namePath) {
		List list = new ArrayList();
		getSubElementsByTagName(namePath, list);
		return new NodeListImpl(list);
	}

	/*
	 * Recursively fullfills the <code>list</code> with all the nodes on the given path.
	 */
	private void getSubElementsByTagName(String name, List list) {
//		String[] keys = name.split(this.TAG_SEPARATOR, 2);
          String[] keys = split(name, this.TAG_SEPARATOR);
		if (keys.length == 1) {
			List l = (List) this.children.get(name);
			if (l != null)
				list.addAll(l);
			return;
		}
		NodeList tagChildren = this.getChildrenByTagName(keys[0]);
		if (tagChildren != null)
			for (int i = 0; i < tagChildren.getLength(); i++)
				((SearchElement) tagChildren.item(i)).getSubElementsByTagName(
					keys[1],
					list);
	}

	/**
	 * Returns a list of <code>Element</code>s in the subtree of this node,
	 * which contain attribute with the given name and value.
	 *
	 * @param attrPath relative path to the attribute name.
	 * @param attrValue attribute value.
	 *
	 * @return list of <code>Element</code>s in the subtree of this node,
	 * which contain attribute with the given name and value.
	 */
	public NodeList getSubElementsByAttrValue(String attrPath, String attrValue) {
//		String[] keys = attrPath.split(this.ATTR_SEPARATOR, 2);
          String[] keys = split(attrPath, this.ATTR_SEPARATOR);
		if (keys.length != 2)
			throw new DOMException(
				DOMException.INVALID_ACCESS_ERR,
				"Parameter not supported");
		List list = new ArrayList();
		getSubElementsByAttrValue(keys[0], keys[1], attrValue, list);
		return new NodeListImpl(list);
	}


	/*
	 * Recursively fullfills the <code>list</code> with all the nodes in the given path.
	 */
	private void getSubElementsByAttrValue(String tagName, String attrName, String attrValue, List list) {
//		String[] keys = tagName.split(this.TAG_SEPARATOR, 2);
                String[] keys = split(tagName, this.TAG_SEPARATOR);
		if (keys.length == 1) {
			List fList = (List) this.children.get(tagName);
			if (fList != null) {
				for (int i = 0; i < fList.size(); i++) {
					Element elm = (Element) fList.get(i);
					String val = (String) elm.getAttribute(attrName);
					if (val != null)
						if (val.equals(attrValue))
							list.add(elm);
				}
			}
			return;
		}
		NodeList tagChildren = this.getChildrenByTagName(keys[0]);
		if (tagChildren != null) {
			for (int i = 0; i < tagChildren.getLength(); i++)
				((SearchElement) tagChildren.item(i)).getSubElementsByAttrValue(
					keys[1],
					attrName,
					attrValue,
					list);
		}
	}


	/**
	 * Returns a list of <code>Element</code>s in the subtree of this node,
	 * with the given tag name and value.
	 *
	 * @param tagPath relative path to the tag name.
	 * @param tagValue <code>Element</code> value.
	 *
	 * @return list of <code>Element</code>s in the subtree of this node,
	 * with the given tag name and value.
	 */
	public NodeList getSubElementsByTagText(String tagPath, String tagValue) {
		List list = new ArrayList();
		getSubElementsByTagText(tagPath, tagValue, list);
		return new NodeListImpl(list);
	}


	/*
	 * Recursively fullfills the <code>list</code> with all the nodes in the given path.
	 * If there is no text node ( text node have value null , -e.g <tag></tag>), this can be matched if
	 * parameter tagValue have value "null".
	 */
	private void getSubElementsByTagText(
		String tagName,
		String tagValue,
		List list) {
//		String[] keys = tagName.split(this.TAG_SEPARATOR, 2);
             String[] keys = split(tagName, this.TAG_SEPARATOR);
		if (keys.length == 1) {
			List fList = (List) this.children.get(tagName);
			if (fList != null) {
				for (int i = 0; i < fList.size(); i++) {
					HashMapElement elm = (HashMapElement) fList.get(i);
					String val = (String) elm.getText();
					if (val != null) {
						if (val.equals(tagValue))
							list.add(elm);
				         } else {
				            if ("null".equals(tagValue))
				              list.add(elm);
				         }
				}
			}
			return;
		}
		NodeList tagChildren = this.getChildrenByTagName(keys[0]);
		if (tagChildren != null) {
			for (int i = 0; i < tagChildren.getLength(); i++)
				((SearchElement) tagChildren.item(i)).getSubElementsByTagText(
					keys[1],
					tagValue,
					list);
		}
	}


        /**
        * Check that the node is either <code>null</code> or an
        * <code>NodeImpl</code>.
        *
        * @exception DOMException if node is not an instance of <code>NodeImpl</code>.
        */
//       protected void checkNode(Node node) throws DOMException {
//               if (node == null) {
//                       return;
//               }
//               if (!(node instanceof SearchElement))
//                       throw new NodeDOMException(DOMException.WRONG_DOCUMENT_ERR, "Node is not an instance of SearchElement!");
//	}

	/**
	 * Returns a list of <code>Element</code>s in the subtree of this node,
	 * that satisfy the given condition.
	 *
	 * @param condition condition.
	 *
	 * @return list of <code>Element</code>s in the subtree of this node,
	 * that satisfy the given condition.
	 */
	public NodeList getSubElementsByCondition(String condition) {
          //code below does not work with jdk1.3
//		if (!condition.matches("([^@=]*)(@?[^@=/]*=[^@=/]*)"))
//			throw new DOMException(
//				DOMException.INVALID_ACCESS_ERR,
//				"Parameter not supported");
//		String[] keys = condition.split(this.EQUAL_SEPARATOR, 2);
                String[] keys = split(condition, this.EQUAL_SEPARATOR);
		String namePath = keys[0];
		if (namePath.indexOf(ATTR_SEPARATOR) != -1)
			return getSubElementsByAttrValue(namePath, keys[1]);
		else
			return getSubElementsByTagText(namePath, keys[1]);
	}


	/**
	 * Returns the first <code>Element</code> in the subtree of this node,
	 * that satisfy the given condition.
	 *
	 * @param condition condition.
	 *
	 * @return the first <code>Element</code> in the subtree of this node,
	 * that satisfy the given condition.
	 */
	public Element getFirstSubElementsByCondition(String condition) {
		NodeList nodes = getSubElementsByCondition(condition);
		if (nodes != null && nodes.getLength() > 0)
			return (Element) nodes.item(0);
		return null;
	}


	/**
	 * Returns the first <code>Element</code> in the subtree of this node,
	 * with the given tag name.
	 *
	 * @param namePath relative path to the <code>Element</code>.
	 *
	 * @return the first <code>Element</code> in the subtree of this node,
	 * with the given tag name.
	 */
	public Element getFirstSubElementByTagName(String namePath) {
		NodeList nodes = getSubElementsByTagName(namePath);
		if (nodes != null && nodes.getLength() > 0)
			return (Element) nodes.item(0);
		return null;
	}


	/**
	 * Return the text of the <code>Element</code> found on the given path.
	 *
	 * @param namePath relative path to the <code>Element</code> node.
	 *
	 * @return text of the <code>Element</code> found on the given path.
	 */
	public String getText(String namePath) {
		NodeList nodes = this.getSubElementsByTagName(namePath);
		if (nodes != null && nodes.getLength() > 0)
			return ((SearchElement) nodes.item(0)).getText();
		return null;
	}


	/**
	 * Sets the given text to the <code>Element</code> found on the given path.
	 *
	 * @param namePath relative path to the <code>Element</code> node.
	 * @param text new text.
	 */
	public void setText(String namePath, String text) {
		NodeList nodes = this.getSubElementsByTagName(namePath);
		if (nodes != null && nodes.getLength() > 0)
			 ((SearchElement) nodes.item(0)).setText(text);
	}


	/**
	 * Sets the value of an attribute found on the given path.
	 *
	 * @param namePath relative path to the attribute.
	 * @param value is new value.
	 */
        public void setAttr(String namePath, String value) {
          //code below does not work with jdk1.3
//		if (!namePath.matches("([^@]*)(@[^@/]*)"))
//			throw new DOMException(
//				DOMException.INVALID_ACCESS_ERR,
//				"Parameter not supported");
//		String[] keys = namePath.split(this.ATTR_SEPARATOR, 2);
                       String[] keys = split(namePath, this.ATTR_SEPARATOR);

                NodeList nodes = this.getSubElementsByTagName(keys[0]);
                if (nodes != null && nodes.getLength() > 0)
                         ((SearchElement) nodes.item(0)).setAttribute(keys[1], value);
        }

        private String[] split(String toSeparate, String separator) {
          String[] keys = new String[2];
          int index = toSeparate.indexOf(separator);
          if( index == -1 ) {
            keys = new String[1];
            keys[0] = toSeparate;
          } else {
            keys[0] = toSeparate.substring(0, index);
            keys[1] = toSeparate.substring(index + 1, toSeparate.length());
          }
          return keys;
        }

}