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Diffstat (limited to 'libjava/gnu/java/beans/decoder/AbstractElementHandler.java')
| -rw-r--r-- | libjava/gnu/java/beans/decoder/AbstractElementHandler.java | 316 |
1 files changed, 0 insertions, 316 deletions
diff --git a/libjava/gnu/java/beans/decoder/AbstractElementHandler.java b/libjava/gnu/java/beans/decoder/AbstractElementHandler.java deleted file mode 100644 index e5578a990bc..00000000000 --- a/libjava/gnu/java/beans/decoder/AbstractElementHandler.java +++ /dev/null @@ -1,316 +0,0 @@ -/* gnu.java.beans.decoder.AbstractElementHandler - Copyright (C) 2004 Free Software Foundation, Inc. - -This file is part of GNU Classpath. - -GNU Classpath is free software; you can redistribute it and/or modify -it under the terms of the GNU General Public License as published by -the Free Software Foundation; either version 2, or (at your option) -any later version. - -GNU Classpath 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 -General Public License for more details. - -You should have received a copy of the GNU General Public License -along with GNU Classpath; see the file COPYING. If not, write to the -Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA -02110-1301 USA. - -Linking this library statically or dynamically with other modules is -making a combined work based on this library. Thus, the terms and -conditions of the GNU General Public License cover the whole -combination. - -As a special exception, the copyright holders of this library give you -permission to link this library with independent modules to produce an -executable, regardless of the license terms of these independent -modules, and to copy and distribute the resulting executable under -terms of your choice, provided that you also meet, for each linked -independent module, the terms and conditions of the license of that -module. An independent module is a module which is not derived from -or based on this library. If you modify this library, you may extend -this exception to your version of the library, but you are not -obligated to do so. If you do not wish to do so, delete this -exception statement from your version. */ - -package gnu.java.beans.decoder; - -import java.beans.ExceptionListener; - -import org.xml.sax.Attributes; - -/** ElementHandler manages a Context instance and interacts with - * its parent and child handlers. - * - * @author Robert Schuster - */ -abstract class AbstractElementHandler implements ElementHandler -{ - /** The Context instance of this handler. The instance is available after the startElement() - * method was called. Otherwise the handler is marked as failed. - */ - private Context context; - - /** The parent handler. */ - private ElementHandler parent; - - /** Stores whether this handler is marked as failed. */ - private boolean hasFailed; - - /** Stores the character data which is contained in the body of the XML tag. */ - private StringBuffer buffer = new StringBuffer(); - - /** Stores whether this ElementHandler can have subelements. The information for this is taken from - * javabeans.dtd which can be found here: - * <a href="http://java.sun.com/products/jfc/tsc/articles/persistence3/">Java Persistence Article</a> - */ - private boolean allowsSubelements; - - /** Creates a new ElementHandler with the given ElementHandler instance - * as parent. - * - * @param parentHandler The parent handler. - */ - protected AbstractElementHandler(ElementHandler parentHandler, - boolean allowsSubs) - { - parent = parentHandler; - allowsSubelements = allowsSubs; - } - - /** Evaluates the attributes and creates a Context instance. - * If the creation of the Context instance fails the ElementHandler - * is marked as failed which may affect the parent handler other. - * - * @param attributes Attributes of the XML tag. - */ - public final void start(Attributes attributes, - ExceptionListener exceptionListener) - { - try - { - // lets the subclass create the appropriate Context instance - context = startElement(attributes, exceptionListener); - } - catch (AssemblyException pe) - { - Throwable t = pe.getCause(); - - if (t instanceof Exception) - exceptionListener.exceptionThrown((Exception) t); - else - throw new InternalError("Unexpected Throwable type in AssemblerException. Please file a bug report."); - - notifyContextFailed(); - - return; - } - } - - /** Analyses the content of the Attributes instance and creates a Context - * object accordingly. - * An AssemblerException is thrown when the Context instance could not - * be created. - * - * @param attributes Attributes of the XML tag. - * @return A Context instance. - * @throws AssemblerException when Context instance could not be created. - */ - protected abstract Context startElement(Attributes attributes, ExceptionListener exceptionListener) - throws AssemblyException; - - /** Post-processes the Context. - */ - public final void end(ExceptionListener exceptionListener) - { - // skips processing if the handler is marked as failed (because the Context - // is then invalid or may not exist at all) - if (!hasFailed) - { - try - { - // note: the order of operations is very important here - // sends the stored character data to the Context - endElement(buffer.toString()); - - // reports to the parent handler if this handler's Context is a - // statement (returning no value BACK to the parent's Context) - if (context.isStatement()) - { - // This may create a valid result in the parent's Context - // or let it fail - parent.notifyStatement(exceptionListener); - - // skips any further processing if the parent handler is now marked - // as failed - if (parent.hasFailed()) - return; - } - - // processes the Context and stores the result - putObject(context.getId(), context.endContext(parent.getContext())); - - // transfers the Context's results to the parent's Context - // if it is an expression (rather than a statement) - if (! context.isStatement()) - parent.getContext().addParameterObject(context.getResult()); - } - catch (AssemblyException pe) - { - // notifies that an exception was thrown in this handler's Context - Throwable t = pe.getCause(); - - if (t instanceof Exception) - exceptionListener.exceptionThrown((Exception) t); - else - throw (InternalError) new InternalError("Severe problem while decoding XML data.") - .initCause(t); - - // marks the handler as failed - notifyContextFailed(); - } - } - } - - /** Notifies the handler's Context that its child Context will not return - * a value back. Some Context variants need this information to know when - * a method or a constructor call can be made. - * - * This method is called by a child handler. - */ - public void notifyStatement(ExceptionListener exceptionListener) - { - try - { - - // propagates to parent handler first to generate objects - // needed by this Context instance - if(context.isStatement()) - { - parent.notifyStatement(exceptionListener); - } - - // Some Context instances do stuff which can fail now. If that - // happens this handler is marked as failed. - context.notifyStatement(parent.getContext()); - } - catch (AssemblyException ae) - { - // notifies that an exception was thrown in this handler's Context - Throwable t = ae.getCause(); - - if (t instanceof Exception) - exceptionListener.exceptionThrown((Exception) t); - else - throw (InternalError) new InternalError("Severe problem while decoding XML data.") - .initCause(t); - - // marks the handler as failed - notifyContextFailed(); - } - } - - /** Marks this and any depending parent handlers as failed. Which means that on their end - * no result is calculated. - * - * When a handler has failed no more handlers are accepted within it. - */ - public final void notifyContextFailed() - { - hasFailed = true; - - // marks the parent handler as failed if its Context - // is affected by the failure of this handler's Context - if (parent.getContext().subContextFailed()) - parent.notifyContextFailed(); - } - - /** Returns whether this handler has failed. - * - * This is used to skip child elements. - * - * @return Whether this handler has failed. - */ - public final boolean hasFailed() - { - return hasFailed; - } - - /** Processes the character data when the element ends. - * - * The default implementation does nothing for convenience. - * - * @param characters - * @throws AssemblerException - */ - protected void endElement(String characters) throws AssemblyException - { - // XXX: throw an exception when unexpected character data is available? - } - - /** Adds characters from the body of the XML tag to the buffer. - * - * @param ch - * @param start - * @param length - * @throws SAXException - */ - public final void characters(char[] ch, int start, int length) - { - // simply appends character data - buffer.append(ch, start, length); - } - - /** Stores an object globally under a unique id. If the id is - * null the object is not stored. - * - * @param objectId - * @param o - */ - public void putObject(String objectId, Object o) - { - if (objectId != null) - parent.putObject(objectId, o); - } - - /** Returns a previously stored object. If the id is null the - * result is null, too. - * - * @param objectId - * @return Returns a previously stored object or null. - */ - public Object getObject(String objectId) throws AssemblyException - { - return objectId == null ? null : parent.getObject(objectId); - } - - /** Returns the Class instance as if called Class.forName() but - * uses a ClassLoader given by the user. - * - * @param className - * @return - * @throws ClassNotFoundException - */ - public Class instantiateClass(String className) - throws ClassNotFoundException - { - return parent.instantiateClass(className); - } - - public final boolean isSubelementAllowed(String subElementName) - { - return allowsSubelements && ! subElementName.equals("java"); - } - - public final Context getContext() - { - return context; - } - - public final ElementHandler getParent() - { - return parent; - } -} |