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diff --git a/libjava/java/io/Externalizable.java b/libjava/java/io/Externalizable.java
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+/* Externalizable.java -- Interface for saving and restoring object data
+   Copyright (C) 1998 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., 59 Temple Place, Suite 330, Boston, MA
+02111-1307 USA.
+
+As a special exception, if you link this library with other files to
+produce an executable, this library does not by itself cause the
+resulting executable to be covered by the GNU General Public License.
+This exception does not however invalidate any other reasons why the
+executable file might be covered by the GNU General Public License. */
+
+
+package java.io;
+
+/**
+  * This interface provides a way that classes can completely control how
+  * the data of their object instances  are written and read to and from 
+  * streams.  It has two methods which are used to write the data to a stream 
+  * and to read the data from a stream.  The read method must read the data 
+  * in exactly the way it was written by the write method. 
+  * <p>
+  * Note that classes which implement this interface must take into account
+  * that all superclass data must also be written to the stream as well.  
+  * The class implementing this interface must figure out how to make that
+  * happen.
+  * <p>
+  * This interface can be used to provide object persistence.  When an 
+  * object is to be stored externally, the <code>writeExternal</code> method is
+  * called to save state.  When the object is restored, an instance is
+  * created using the default no-argument constructor and the 
+  * <code>readExternal</code> method is used to restore the state.
+  *
+  * @version 0.0
+  *
+  * @author Aaron M. Renn (arenn@urbanophile.com)
+  */
+public abstract interface Externalizable extends Serializable
+{
+
+/**
+  * This method restores an object's state by reading in the instance data
+  * for the object from the passed in stream.  Note that this stream is not
+  * a subclass of <code>InputStream</code>, but rather is a class that implements
+  * the <code>ObjectInput</code> interface.  That interface provides a mechanism for
+  * reading in Java data types from a stream.
+  * <p>
+  * Note that this method must be compatible with <code>writeExternal</code>.
+  * It must read back the exact same types that were written by that
+  * method in the exact order they were written.
+  * <p>
+  * If this method needs to read back an object instance, then the class
+  * for that object must be found and loaded.  If that operation fails,
+  * then this method throws a <code>ClassNotFoundException</code>
+  *
+  * @param in An <code>ObjectInput</code> instance for reading in the object state
+  *
+  * @exception ClassNotFoundException If the class of an object being restored cannot be found
+  * @exception IOException If any other error occurs
+  */
+public abstract void
+readExternal(ObjectInput in) throws ClassNotFoundException, IOException;
+
+/*************************************************************************/
+
+/**
+  * This method is responsible for writing the instance data of an object
+  * to the passed in stream.  Note that this stream is not a subclass of
+  * <code>OutputStream</code>, but rather is a class that implements the
+  * <code>ObjectOutput</code> interface.  That interface provides a number of methods
+  * for writing Java data values to a stream.
+  * <p>
+  * Not that the implementation of this method must be coordinated with
+  * the implementation of <code>readExternal</code>.
+  *
+  * @param out An <code>ObjectOutput</code> instance for writing the object state
+  *
+  * @exception IOException If an error occurs
+  */
+public abstract void
+writeExternal(ObjectOutput out) throws IOException;
+
+} // interface Externalizable
+