diff options
Diffstat (limited to 'libjava/java/beans/XMLDecoder.java')
| -rw-r--r-- | libjava/java/beans/XMLDecoder.java | 307 |
1 files changed, 0 insertions, 307 deletions
diff --git a/libjava/java/beans/XMLDecoder.java b/libjava/java/beans/XMLDecoder.java deleted file mode 100644 index 238fd6b..0000000 --- a/libjava/java/beans/XMLDecoder.java +++ /dev/null @@ -1,307 +0,0 @@ -/* java.beans.XMLDecoder -- - Copyright (C) 2004, 2005 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 java.beans; - -import gnu.java.beans.decoder.DefaultExceptionListener; -import gnu.java.beans.decoder.PersistenceParser; - -import java.io.IOException; -import java.io.InputStream; -import java.util.Iterator; -import java.util.NoSuchElementException; - -/** - * The XMLDecoder reads XML data that is structured according to - * <a href="http://java.sun.com/products/jfc/tsc/articles/persistence3/javabeans.dtd">this</a> DTD - * and creates objects according to the content. Usually such data is generated using the - * {@link XMLEncoder} class. - * <p> - * An example XML document might look like this: - * <code> - * <java> - * <string>Hello World</string> - * <int>200</int> - * </java> - * </code> - * <p>To read the <code>String</code> and the <code>Integer</code> instance the following can be used (assume - * the XML data can be obtained from the InputStream):</p> - * <code> - * XMLDecoder decoder = new XMLDecoder(inputStreamContainingXMLData); - * String message = (String) decoder.readObject(); - * Integer number = (Integer) decoder.readObject(); - * </code> - * <p>Besides this basic functionality the <code>XMLDecoder</code> has some more features that might come - * handy in certain situations:</p> - * <p>An owner object can be set using the <code>setOwner</code> method which can then be accessed when - * decoding. This feature is only useful if the XML data is aware of the owner object. Such data may - * look like this (assume that the owner object is a JFrame instance):</p> - * <code> - * <java> - * <void method="getOwner"> - * <void method="setVisible"> - * <boolean>true<boolean> - * </void> - * </void> - * </java> - * </code> - * This accesses the <code>JFrame</code> and makes it visible using the <code>setVisible</code> method. - * <p>Please note that changing the owner <b>after</b> the having read the first object has no effect, - * because all object have been decoded then.</p> - * <p>If the <code>XMLDecoder</code> is created with no {@link ExceptionListener} instance a default one - * is used that prints an error message to <code>System.err</code> whenever a recoverable exception - * is thrown. Recovarable exceptions occur when the XML data cannot be interpreted correctly (e.g - * unknown classes or methods, invocation on null, ...). In general be very careful when the - * <code>XMLDecoder</code> provoked such exceptions because the resulting object(s) may be in an - * undesirable state.</p> - * <p>Note that changing the ExceptionListener instance after <code>readObject</code> has been called - * once has no effect because the decoding is completed then.</p> - * <p>At last one can provide a specific <code>ClassLoader</code> which is then used when <code>Class</code> - * objects are accessed. See {@link java.lang.Class#forName(String, boolean, ClassLoader)} for details - * on this.</p> - * <p>Note: If the <code>InputStream</code> instance given to any of the constructors is <code>null</code> - * the resulting <code>XMLDecoder</code> will be silently (without any exception) useless. Each call - * to <code>readObject</code> will return <code>null</code> and never throws an - * <code>ArrayIndexOutOfBoundsException</code>.</p> - * - * @author Robert Schuster - * @since 1.4 - * @status updated to 1.5 - */ -public class XMLDecoder -{ - private Object owner; - - private ExceptionListener exceptionListener; - - private InputStream inputStream; - - private boolean isStreamClosed; - - private ClassLoader classLoader; - - private Iterator iterator; - - /** Creates a XMLDecoder instance that parses the XML data of the given input stream. - * Using this constructor no special ClassLoader, a default ExceptionListener - * and no owner object is used. - * - * @param in InputStream to read XML data from. - */ - public XMLDecoder(InputStream in) - { - this(in, null); - } - - /** Creates a XMLDecoder instance that parses the XML data of the given input stream. - * Using this constructor no special ClassLoader and a default ExceptionListener - * is used. - * - * @param in InputStream to read XML data from. - * @param owner Owner object which can be accessed and modified while parsing. - */ - public XMLDecoder(InputStream in, Object owner) - { - this(in, owner, null); - } - - /** Creates a XMLDecoder instance that parses the XML data of the given input stream. - * If the ExceptionListener argument is null a default implementation is used. - * - * @param in InputStream to read XML data from. - * @param owner Owner object which can be accessed and modified while parsing. - * @param exceptionListener ExceptionListener instance to which exception notifications are send. - */ - public XMLDecoder( - InputStream in, - Object owner, - ExceptionListener exceptionListener) - { - this( - in, - owner, - exceptionListener, - Thread.currentThread().getContextClassLoader()); - } - - /** Creates a XMLDecoder instance that parses the XML data of the given input stream. - * If the ExceptionListener argument is null a default implementation is used. - * - * @param in InputStream to read XML data from. - * @param owner Owner object which can be accessed and modified while parsing. - * @param exceptionListener ExceptionListener instance to which exception notifications are send. - * @param cl ClassLoader instance that is used for calls to <code>Class.forName(String, boolean, ClassLoader)</code> - * @since 1.5 - */ - public XMLDecoder( - InputStream in, - Object owner, - ExceptionListener listener, - ClassLoader cl) - { - // initially here was a check for the validity of the InputStream argument but some - // great engineers decided that this API should silently discard this and behave rather - // odd: readObject will always return null ... - inputStream = in; - - setExceptionListener(listener); - - // validity of this object is checked in Class.forName() and therefore may be null - classLoader = cl; - - this.owner = owner; - } - - /** Closes the stream associated with this decoder. This should be done after having read all - * decoded objects. - * <p>See the description of the {@link #readObject()} for the effect caused by <code>close</code>.</p> - */ - public void close() - { - if (isStreamClosed) - { - return; - } - - try - { - inputStream.close(); - isStreamClosed = true; - } - catch (IOException e) - { - // bad style forced by original API design ... - } - } - - /** Returns the ExceptionListener instance associated with this decoder. - * <p>See the description of {@link XMLDecoder} class for more information on the ExceptionListener.</p> - * - * @return Current ExceptionListener of the decoder. - */ - public ExceptionListener getExceptionListener() - { - return exceptionListener; - } - - /** Returns the owner object of the decoder. This method is usually called - * from within the parsed XML data. - * <p>See the description of {@link XMLDecoder} class for more information on the owner object.</p> - * - * @return The owner object of this decoder. - */ - public Object getOwner() - { - return owner; - } - - /** Returns the next available decoded object. - * <p>Note that the actual decoding takes place when the method is called for the first time.</p> - * <p>If the <code>close</code> method was already called a <code>NoSuchElementException</code> - * is thrown.</p> - * <p>If the InputStream instance used in the constructors was <code>null</code> this method - * will always return <code>null</code> itself.</p> - * - * @return The next object in a sequence decoded from XML data. - * @throws ArrayIndexOutOfBoundsException When no more objects are available. - */ - public Object readObject() throws ArrayIndexOutOfBoundsException - { - // note: the RI does it this way ... - if(inputStream == null) { - return null; - } - - // note: the original API documentation says nothing on what to do - // when the stream was closed before readObject is called but it actually - // throws a NoSuchElementException - this behaviour is imitated here - if (isStreamClosed) - { - throw new NoSuchElementException("Cannot read any objects - XMLDecoder was already closed."); - } - - // creates the PersistenceParser (doing the parsing and decoding) and returns its - // Iterator on first invocation - if (iterator == null) - { - iterator = - new PersistenceParser( - inputStream, - exceptionListener, - classLoader, - this) - .iterator(); - } - - // note: done according to the official documentation - if (!iterator.hasNext()) - { - throw new ArrayIndexOutOfBoundsException("No more objects available from this XMLDecoder."); - } - - // returns just the next object if there was no problem - return iterator.next(); - } - - /** Sets the ExceptionListener instance to which notifications of exceptions are send - * while parsing the XML data. - * <p>See the description of {@link XMLDecoder} class for more information on the ExceptionListener.</p> - * - * @param listener - */ - public void setExceptionListener(ExceptionListener listener) - { - // uses a default implementation when null - if (listener == null) - { - listener = new DefaultExceptionListener(); - } - exceptionListener = listener; - } - - /** Sets the owner object which can be accessed from the parsed XML data. - * <p>See the description of {@link XMLDecoder} class for more information on the owner object.</p> - * - * @param newOwner - */ - public void setOwner(Object newOwner) - { - owner = newOwner; - } - -} |