MetaData


1   /*
2   * JBoss, Home of Professional Open Source
3   * Copyright 2005, JBoss Inc., and individual contributors as indicated
4   * by the @authors tag. See the copyright.txt in the distribution for a
5   * full listing of individual contributors.
6   *
7   * This is free software; you can redistribute it and/or modify it
8   * under the terms of the GNU Lesser General Public License as
9   * published by the Free Software Foundation; either version 2.1 of
10  * the License, or (at your option) any later version.
11  *
12  * This software is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with this software; if not, write to the Free
19  * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
20  * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
21  */
22  package org.jboss.metadata;
23  
24  import java.util.ArrayList  ;
25  import java.util.Iterator  ;
26  
27  import org.w3c.dom.Element  ;
28  import org.w3c.dom.NodeList  ;
29  import org.w3c.dom.Node  ;
30  
31  import org.jboss.deployment.DeploymentException;
32  import org.jboss.logging.Logger;
33  import org.jboss.util.StringPropertyReplacer;
34  
35  /**
36   * An abstract base class for metadata containers.
37   *
38   * @author <a HREF="mailto:sebastien.alborini@m4x.org">Sebastien Alborini</a>
39   * @version $Revision: 37459 $
40   */
41  public abstract class MetaData
42     implements Cloneable  , XmlLoadable
43  {
44     // Constants -----------------------------------------------------
45  
46     protected static Logger log = Logger.getLogger(MetaData.class);
47     
48     // These do not really belong here
49  
50     public static final byte TX_NOT_SUPPORTED  = 0;
51     public static final byte TX_REQUIRED       = 1;
52     public static final byte TX_SUPPORTS       = 2;
53     public static final byte TX_REQUIRES_NEW   = 3;
54     public static final byte TX_MANDATORY      = 4;
55     public static final byte TX_NEVER          = 5;
56     public static final byte TX_UNKNOWN        = 6;
57  
58     // Attributes ----------------------------------------------------
59  
60     // Static --------------------------------------------------------
61  
62     /**
63      * Returns an iterator over the children of the given element with
64      * the given tag name.
65      *
66      * @param element    The parent element
67      * @param tagName    The name of the desired child
68      * @return           An interator of children or null if element is null.
69      */
70     public static Iterator   getChildrenByTagName(Element   element,
71                                                 String   tagName)
72     {
73        if (element == null) return null;
74        // getElementsByTagName gives the corresponding elements in the whole 
75        // descendance. We want only children
76  
77        NodeList   children = element.getChildNodes();
78        ArrayList   goodChildren = new ArrayList  ();
79        for (int i=0; i<children.getLength(); i++) {
80           Node   currentChild = children.item(i);
81           if (currentChild.getNodeType() == Node.ELEMENT_NODE && 
82               ((Element  )currentChild).getTagName().equals(tagName)) {
83              goodChildren.add(currentChild);
84           }
85        }
86        return goodChildren.iterator();
87     }
88  
89     /**
90      * Gets the child of the specified element having the specified unique
91      * name.  If there are more than one children elements with the same name
92      * and exception is thrown.
93      *
94      * @param element    The parent element
95      * @param tagName    The name of the desired child
96      * @return           The named child.
97      *
98      * @throws DeploymentException   Child was not found or was not unique.
99      */
100    public static Element   getUniqueChild(Element   element, String   tagName)
101       throws DeploymentException
102    {
103       Iterator   goodChildren = getChildrenByTagName(element, tagName);
104 
105       if (goodChildren != null && goodChildren.hasNext()) {
106          Element   child = (Element  )goodChildren.next();
107          if (goodChildren.hasNext()) {
108             throw new DeploymentException
109                ("expected only one " + tagName + " tag");
110          }
111          return child;
112       } else {
113          throw new DeploymentException
114             ("expected one " + tagName + " tag");
115       }
116    }
117 
118    /**
119     * Gets the child of the specified element having the
120     * specified name. If the child with this name doesn't exist
121     * then null is returned instead.
122     *
123     * @param element the parent element
124     * @param tagName the name of the desired child
125     * @return either the named child or null
126     */
127    public static Element   getOptionalChild(Element   element, String   tagName)
128       throws DeploymentException
129    {
130       return getOptionalChild(element, tagName, null);
131    }
132 
133    /**
134     * Gets the child of the specified element having the
135     * specified name. If the child with this name doesn't exist
136     * then the supplied default element is returned instead.
137     *
138     * @param element the parent element
139     * @param tagName the name of the desired child
140     * @param defaultElement the element to return if the child
141     *                       doesn't exist
142     * @return either the named child or the supplied default
143     */
144    public static Element   getOptionalChild(Element   element,
145                                           String   tagName,
146                                           Element   defaultElement)
147       throws DeploymentException
148    {
149       Iterator   goodChildren = getChildrenByTagName(element, tagName);
150 
151       if (goodChildren != null && goodChildren.hasNext()) {
152          Element   child = (Element  )goodChildren.next();
153          if (goodChildren.hasNext()) {
154             throw new DeploymentException
155                ("expected only one " + tagName + " tag");
156          }
157          return child;
158       } else {
159          return defaultElement;
160       }
161    }
162 
163    /**
164     * Get an attribute value of the given element.
165     *
166     * @param element    The element to get the attribute value for.
167     * @param attrName   The attribute name
168     * @return           The attribute value or null.
169     */
170    public static String   getElementAttribute(final Element   element, final String   attrName)
171    {
172       return getElementAttribute(element, attrName, true);
173    }
174 
175    /**
176     * Get an attribute value of the given element.
177     *
178     * @param element    The element to get the attribute value for.
179     * @param attrName   The attribute name
180     * @param replace    Whether to replace system properties
181     * @return           The attribute value or null.
182     */
183    public static String   getElementAttribute(final Element   element, final String   attrName, boolean replace)
184    {
185       if (element == null)
186          return null;
187 
188       if (attrName == null || element.hasAttribute(attrName) == false)
189          return null;
190 
191       String   result = element.getAttribute(attrName);
192       if (replace)
193          return StringPropertyReplacer.replaceProperties(result.trim());
194       else
195          return result.trim();
196    }
197 
198    /**
199     * Get the content of the given element.
200     *
201     * @param element    The element to get the content for.
202     * @return           The content of the element or null.
203     */
204    public static String   getElementContent(final Element   element)
205    {
206       return getElementContent(element, null);
207    }
208 
209    /**
210     * Get the content of the given element.
211     *
212     * @param element       The element to get the content for.
213     * @param defaultStr    The default to return when there is no content.
214     * @return              The content of the element or the default.
215     */
216    public static String   getElementContent(Element   element, String   defaultStr)
217    {
218       return getElementContent(element, defaultStr, true);
219    }
220 
221    /**
222     * Get the content of the given element.
223     *
224     * @param element       The element to get the content for.
225     * @param defaultStr    The default to return when there is no content.
226     * @param replace       Whether to replace system properties
227     * @return              The content of the element or the default.
228     */
229    public static String   getElementContent(Element   element, String   defaultStr, boolean replace)
230    {
231       if (element == null)
232          return defaultStr;
233 
234       NodeList   children = element.getChildNodes();
235       String   result = "";
236       for (int i = 0; i < children.getLength(); i++)
237       {
238          if (children.item(i).getNodeType() == Node.TEXT_NODE || 
239              children.item(i).getNodeType() == Node.CDATA_SECTION_NODE)
240          {
241             result += children.item(i).getNodeValue();
242          }
243          else if( children.item(i).getNodeType() == Node.COMMENT_NODE )
244          {
245             // Ignore comment nodes
246          }
247          else
248          {
249             result += children.item(i).getFirstChild();
250          }
251       }
252       if (replace)
253          return StringPropertyReplacer.replaceProperties(result.trim());
254       else
255          return result.trim();
256    }
257 
258    public static String   getFirstElementContent(Element   element, String   defaultStr)
259    {
260       return getFirstElementContent(element, defaultStr, true);
261    }
262 
263    public static String   getFirstElementContent(Element   element, String   defaultStr, boolean replace)
264    {
265       if (element == null)
266          return defaultStr;
267 
268       NodeList   children = element.getChildNodes();
269       String   result = "";
270       for (int i = 0; i < children.getLength(); i++)
271       {
272          if (children.item(i).getNodeType() == Node.TEXT_NODE ||
273              children.item(i).getNodeType() == Node.CDATA_SECTION_NODE)
274          {
275             String   val = children.item(i).getNodeValue();
276             result += val;
277          }
278          else if( children.item(i).getNodeType() == Node.COMMENT_NODE )
279          {
280             // Ignore comment nodes
281          }
282          /*  For some reason, the original version gets the text of the first child
283          else
284          {
285             result += children.item(i).getFirstChild();
286          }
287          */
288       }
289       if (replace)
290          return StringPropertyReplacer.replaceProperties(result.trim());
291       else
292          return result.trim();
293    }
294 
295    /**
296     * Macro to get the content of a unique child element.
297     *
298     * @param element    The parent element.
299     * @param tagName    The name of the desired child.
300     * @return           The element content or null.
301     */
302    public static String   getUniqueChildContent(Element   element,
303                                               String   tagName)
304       throws DeploymentException
305    {
306       return getElementContent(getUniqueChild(element, tagName));
307    }
308 
309    /**
310     * Macro to get the content of an optional child element.
311     * 
312     * @param element    The parent element.
313     * @param tagName    The name of the desired child.
314     * @return           The element content or null.
315     */
316    public static String   getOptionalChildContent(Element   element,
317                                                 String   tagName)
318       throws DeploymentException
319    {
320       return getElementContent(getOptionalChild(element, tagName));
321    }
322 
323    /**
324     * Macro to get the content of an optional child element with default value.
325     *
326     * @param element    The parent element.
327     * @param tagName    The name of the desired child.
328     * @return           The element content or null.
329     */
330    public static String   getOptionalChildContent(Element   element, String   tagName, String   defaultValue)
331            throws DeploymentException
332    {
333       return getElementContent(getOptionalChild(element, tagName), defaultValue);
334    }
335 
336    public static boolean getOptionalChildBooleanContent(Element   element, String   name)
337       throws DeploymentException
338    {
339       Element   child = getOptionalChild(element, name);
340       if(child != null)
341       {
342          String   value = getElementContent(child).toLowerCase();
343          return value.equalsIgnoreCase("true") || value.equalsIgnoreCase("yes");
344       }
345 
346       return false;
347    }
348 
349    public static boolean getOptionalChildBooleanContent(Element   element,
350       String   name, boolean defaultValue)
351       throws DeploymentException
352    {
353       Element   child = getOptionalChild(element, name);
354       boolean flag = defaultValue;
355       if(child != null)
356       {
357          String   value = getElementContent(child).toLowerCase();
358          flag = value.equalsIgnoreCase("true") || value.equalsIgnoreCase("yes");
359       }
360 
361       return flag;
362    }
363 
364    // Constructors --------------------------------------------------
365 
366    // Public --------------------------------------------------------
367 
368    /** Create a field wise copy of the object.
369    */
370    public Object   clone()
371    {
372       Object   clone = null;
373       try
374       {
375          clone = super.clone();
376       }
377       catch(CloneNotSupportedException   ignore)
378       {
379       }
380       return clone;
381    }
382 
383    /**
384     * Imports either the jboss or ejb-jar from the given element.
385     *
386     * @param element   The element to import.
387     * 
388     * @throws DeploymentException    Unrecognized root tag.
389     */
390    public void importXml(Element   element) throws DeploymentException {
391       String   rootTag = element.getOwnerDocument().
392          getDocumentElement().getTagName();
393 
394       if (rootTag.equals("jboss")) {
395          // import jboss.xml
396          importJbossXml(element);
397       } else if (rootTag.equals("ejb-jar")) {
398          // import ejb-jar.xml
399          importEjbJarXml(element);
400       } else {
401          throw new DeploymentException("Unrecognized root tag : "+ rootTag);
402       }
403    }
404 
405    /**
406     * Non-operation.
407     *
408     * @param element
409     *
410     * @throws DeploymentException
411     */
412    public void importEjbJarXml(Element   element) throws DeploymentException {
413       // empty
414    }
415 
416    /**
417     * Non-operation.
418     *
419     * @param element
420     *
421     * @throws DeploymentException
422     */
423    public void importJbossXml(Element   element) throws DeploymentException {
424       // empty
425    }
426 
427    // Package protected ---------------------------------------------
428 
429    // Protected -----------------------------------------------------
430 
431    /**
432     * Check if we are running in a JDK v1.3 virtual machine or better.
433     *
434     * @return    True if the virtual machine is v1.3 or better.
435     */
436    protected boolean jdk13Enabled() {
437       // should use "java.version" ?
438       String   javaVersion = System.getProperty("java.vm.version");
439       return javaVersion.compareTo("1.3") >= 0;
440    }
441 
442    // Private -------------------------------------------------------
443 
444    // Inner classes -------------------------------------------------
445 }
446 /*
447 vim:ts=3:sw=3:et
448 */
449
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