gomp-20050608-branch/libjava/classpath/gnu/java/beans/decoder/ElementHandler.java

   1 /* gnu.java.beans.decoder.ElementHandler
   2    Copyright (C) 2004 Free Software Foundation, Inc.
   3
   4 This file is part of GNU Classpath.
   5
   6 GNU Classpath is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU Classpath is distributed in the hope that it will be useful, but
  12 WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Classpath; see the file COPYING.  If not, write to the
  18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19 02110-1301 USA.
  20
  21 Linking this library statically or dynamically with other modules is
  22 making a combined work based on this library.  Thus, the terms and
  23 conditions of the GNU General Public License cover the whole
  24 combination.
  25
  26 As a special exception, the copyright holders of this library give you
  27 permission to link this library with independent modules to produce an
  28 executable, regardless of the license terms of these independent
  29 modules, and to copy and distribute the resulting executable under
  30 terms of your choice, provided that you also meet, for each linked
  31 independent module, the terms and conditions of the license of that
  32 module.  An independent module is a module which is not derived from
  33 or based on this library.  If you modify this library, you may extend
  34 this exception to your version of the library, but you are not
  35 obligated to do so.  If you do not wish to do so, delete this
  36 exception statement from your version. */
  37
  38 package gnu.java.beans.decoder;
  39
  40 import java.beans.ExceptionListener;
  41
  42 import org.xml.sax.Attributes;
  43
  44 /** ElementHandler manages a Context instance and interacts with
  45  * its parent and child handlers.
  46  *
  47  * @author Robert Schuster
  48  */
  49 interface ElementHandler
  50 {
  51   /** Evaluates the attributes and creates a Context instance.
  52    * If the creation of the Context instance fails the ElementHandler
  53    * is marked as failed which may affect the parent handler other.
  54    *
  55    * @param attributes Attributes of the XML tag.
  56    */
  57   void start(Attributes attributes, ExceptionListener exceptionListener);
  58
  59   /** Post-processes the Context.
  60    */
  61   void end(ExceptionListener exceptionListener);
  62
  63   /** Adds characters from the body of the XML tag to the buffer.
  64    *
  65    * @param ch
  66    * @param start
  67    * @param length
  68    * @throws SAXException
  69    */
  70   void characters(char[] ch, int start, int length);
  71
  72   /** Returns whether a subelement of the given name is allowed. The rules
  73    * for evaluating this are derived from the javabeans.dtd which can be found
  74    * here: <a href="http://java.sun.com/products/jfc/tsc/articles/persistence3">Java Persistence Article</a>.
  75    *
  76    * @param subElementName
  77    * @return
  78    */
  79   boolean isSubelementAllowed(String subElementName);
  80
  81   /** Provides the same functionality as Class.forName() but allows the decoder
  82    * to use a different class loader.
  83    *
  84    * @param className
  85    * @return
  86    * @throws ClassNotFoundException
  87    */
  88   Class instantiateClass(String className) throws ClassNotFoundException;
  89
  90   /** Notifies the handler's Context that its child Context will not return
  91    * a value back. Some Context variants need this information to know when
  92    * a method or a constructor call can be made.
  93    *
  94    * This method is called by a child handler.
  95    */
  96   void notifyStatement(ExceptionListener exceptionListener);
  97
  98   /** Returns whether this handler has failed.
  99    *
 100    * This is used to skip child elements.
 101    *
 102    * @return Whether this handler has failed.
 103    */
 104   boolean hasFailed();
 105
 106   /** Returns the Context instance this handler is working on.
 107    *
 108    * @return The handler's Context instance.
 109    */
 110   Context getContext();
 111
 112   /** Notifies the handler that its Context failed and starts a recursive
 113    * invocation of the parent handler if it is affected by that failure.
 114    *
 115    * Although the method is a public API member it is only used internally.
 116    */
 117   void notifyContextFailed();
 118
 119   /** Stores the object under the given id. The object is not stored if the
 120    * id is null.
 121    *
 122    * @param objectId
 123    * @param o
 124    */
 125   void putObject(String objectId, Object o);
 126
 127   Object getObject(String objectId) throws AssemblyException;
 128
 129   ElementHandler getParent();
 130 }