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Java > Open Source Codes > org > xmldb > xupdate > lexus > commands > CommandObject


1 package org.xmldb.xupdate.lexus.commands;
2
3 /*
4  * The XML:DB Initiative Software License, Version 1.0
5  *
6  *
7  * Copyright (c) 2000-2003 The XML:DB Initiative. All rights
8  * reserved.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  *
14  * 1. Redistributions of source code must retain the above copyright
15  * notice, this list of conditions and the following disclaimer.
16  *
17  * 2. Redistributions in binary form must reproduce the above copyright
18  * notice, this list of conditions and the following disclaimer in
19  * the documentation and/or other materials provided with the
20  * distribution.
21  *
22  * 3. The end-user documentation included with the redistribution,
23  * if any, must include the following acknowledgment:
24  * "This product includes software developed by the
25  * XML:DB Initiative (http://www.xmldb.org/)."
26  * Alternately, this acknowledgment may appear in the software itself,
27  * if and wherever such third-party acknowledgments normally appear.
28  *
29  * 4. The name "XML:DB Initiative" must not be used to endorse or
30  * promote products derived from this software without prior written
31  * permission. For written permission, please contact info@xmldb.org.
32  *
33  * 5. Products derived from this software may not be called "XML:DB",
34  * nor may "XML:DB" appear in their name, without prior written
35  * permission of the XML:DB Initiative.
36  *
37  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
38  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
39  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
40  * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
41  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
42  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
43  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
44  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
45  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
46  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
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48  * SUCH DAMAGE.
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51  * This software consists of voluntary contributions made by many
52  * individuals on behalf of the XML:DB Initiative. For more information
53  * on the XML:DB Initiative, please see <http://www.xmldb.org/>.
54  */
55
56 import org.w3c.dom.Document JavaDoc;
57 import org.w3c.dom.Node JavaDoc;
58 import org.w3c.dom.NodeList JavaDoc;
59 import org.xmldb.common.xml.queries.XObject;
60 import org.xmldb.common.xml.queries.XPathQuery;
61 import org.xmldb.common.xml.queries.XPathQueryFactory;
62
63 import java.util.Hashtable JavaDoc;
64 import java.util.Vector JavaDoc;
65
66 /**
67  *
68  * @version $Id: CommandObject.java,v 1.7 2003/05/21 13:11:51 jbreedveld Exp $
69  * @author <a HREF="http://www.smb-tec.com">SMB</a>
70  */
71 public abstract class CommandObject extends Object JavaDoc {
72
73   /* */
74   private XPathQuery xpath = null;
75   /* */
76   protected Document JavaDoc document = null;
77   /* */
78   protected Node JavaDoc contextNode = null;
79   /* */
80   protected NodeList JavaDoc selectionNodeList = null;
81   /* */
82   protected Hashtable JavaDoc attributes = null;
83   /* */
84   protected Vector JavaDoc characters = null;
85
86
87   /**
88    * <B>
89    * XPath from Xt has problems with namespaces. To ensure correct
90    * working use the XPath from Xalan or any other namespace aware
91    * XPath implementation.
92    * </B>
93    *
94    * @param contextNode
95    */
96   public CommandObject(Node JavaDoc contextNode) throws Exception JavaDoc {
97     if (contextNode == null) {
98       throw new IllegalArgumentException JavaDoc("Argument contextNode must not be null.");
99     }
100     if (xpath == null) {
101       xpath = XPathQueryFactory.newInstance().newXPathQuery();
102     }
103     this.contextNode = contextNode;
104     switch (contextNode.getNodeType()) {
105       case Node.DOCUMENT_NODE:
106         document = (Document JavaDoc) contextNode;
107         break;
108       default:
109         document = contextNode.getOwnerDocument();
110     }
111     characters = new Vector JavaDoc();
112   }
113
114   /**
115    *
116    */
117   public void reset() {
118     characters.clear();
119   }
120
121   /**
122    * The given XPath expression <code>qString</code> will be executed and
123    * will be used as the new context node - or if more then one node is
124    * selected - as an array of context nodes. All given modifications will
125    * be affect the selected context node.
126    *
127    * @param qString the XPath expression that selects the new context node.
128    * @throws IllegalArgumentException If the given XPath expression is null.
129    */
130   public synchronized void selectNodes(String JavaDoc qString) throws Exception JavaDoc {
131     if (qString == null) {
132       throw new IllegalArgumentException JavaDoc("Argument qString must not be null.");
133     }
134     xpath.setQString(qString);
135     XObject result = xpath.execute(contextNode);
136     if (result.getType() != XObject.CLASS_NODESET) {
137       throw new Exception JavaDoc("XPath leads not to a Node or NodeList !");
138     }
139     selectionNodeList = result.nodeset();
140     if (selectionNodeList.getLength() == 0) {
141 // throw new LexusException(LexusException.NO_NODES_SELECTED);
142 throw new Exception JavaDoc(".selectNodes(): No nodes selected: " + qString);
143     }
144   }
145
146
147   /**
148    * @param attributes
149    */
150   public void submitAttributes(Hashtable JavaDoc attributes) {
151     this.attributes = attributes;
152   }
153
154
155   /**
156    * @param data
157    */
158   public void submitCharacters(String JavaDoc data) {
159     characters.addElement(data);
160   }
161
162
163   /**
164    * @param instruction
165    */
166   public abstract boolean submitInstruction(int instruction) throws Exception JavaDoc;
167
168
169   /**
170    *
171    */
172   public abstract boolean executeInstruction() throws Exception JavaDoc;
173
174
175   /**
176    *
177    */
178   public abstract Node JavaDoc execute() throws Exception JavaDoc;
179
180 }
181
182
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