FileBasedFactory.java, [...]: New files, all merged from classpath.

2003-02-13  Michael Koch  <konqueror@gmx.de>

	* gnu/java/util/prefs/FileBasedFactory.java,
	gnu/java/util/prefs/MemmoryBasedFactory.java,
	gnu/java/util/prefs/MemoryBasedPreferences.java,
	gnu/java/util/prefs/NodeReader.java,
	gnu/java/util/prefs/NodeWriter.java,
	java/util/prefs/AbstractPreferences.java,
	java/util/prefs/BackingStoreException.java,
	java/util/prefs/InvalidPreferencesFormatException.java,
	java/util/prefs/NodeChangeEvent.java,
	java/util/prefs/NodeChangeListener.java,
	java/util/prefs/PreferenceChangeEvent.java,
	java/util/prefs/PreferenceChangeListener.java,
	java/util/prefs/Preferences.java,
	java/util/prefs/PreferencesFactory.java:
	New files, all merged from classpath.
	* Makefile.am
	(ordinary_java_source_files): Added the following files:
	gnu/java/util/prefs/FileBasedFactory.java,
	gnu/java/util/prefs/MemmoryBasedFactory.java,
	gnu/java/util/prefs/MemoryBasedPreferences.java,
	gnu/java/util/prefs/NodeReader.java,
	gnu/java/util/prefs/NodeWriter.java,
	(core_java_source_files): Added the following files:
	java/util/prefs/AbstractPreferences.java,
	java/util/prefs/BackingStoreException.java,
	java/util/prefs/InvalidPreferencesFormatException.java,
	java/util/prefs/NodeChangeEvent.java,
	java/util/prefs/NodeChangeListener.java,
	java/util/prefs/PreferenceChangeEvent.java,
	java/util/prefs/PreferenceChangeListener.java,
	java/util/prefs/Preferences.java,
	java/util/prefs/PreferencesFactory.java
	* Makefile.in: Regenerated.

From-SVN: r62827

libjava/ChangeLog

 2003-02-13  Michael Koch  <konqueror@gmx.de>
+ 
+	* gnu/java/util/prefs/FileBasedFactory.java,
+	gnu/java/util/prefs/MemmoryBasedFactory.java,
+	gnu/java/util/prefs/MemoryBasedPreferences.java,
+	gnu/java/util/prefs/NodeReader.java,
+	gnu/java/util/prefs/NodeWriter.java,
+	java/util/prefs/AbstractPreferences.java,
+	java/util/prefs/BackingStoreException.java,
+	java/util/prefs/InvalidPreferencesFormatException.java,
+	java/util/prefs/NodeChangeEvent.java,
+	java/util/prefs/NodeChangeListener.java,
+	java/util/prefs/PreferenceChangeEvent.java,
+	java/util/prefs/PreferenceChangeListener.java,
+	java/util/prefs/Preferences.java,
+	java/util/prefs/PreferencesFactory.java:
+	New files, all merged from classpath.
+	* Makefile.am
+	(ordinary_java_source_files): Added the following files:
+	gnu/java/util/prefs/FileBasedFactory.java,
+	gnu/java/util/prefs/MemmoryBasedFactory.java,
+	gnu/java/util/prefs/MemoryBasedPreferences.java,
+	gnu/java/util/prefs/NodeReader.java,
+	gnu/java/util/prefs/NodeWriter.java,
+	(core_java_source_files): Added the following files:
+	java/util/prefs/AbstractPreferences.java,
+	java/util/prefs/BackingStoreException.java,
+	java/util/prefs/InvalidPreferencesFormatException.java,
+	java/util/prefs/NodeChangeEvent.java,
+	java/util/prefs/NodeChangeListener.java,
+	java/util/prefs/PreferenceChangeEvent.java,
+	java/util/prefs/PreferenceChangeListener.java,
+	java/util/prefs/Preferences.java,
+	java/util/prefs/PreferencesFactory.java
+	* Makefile.in: Regenerated.
+ 
+2003-02-13  Michael Koch  <konqueror@gmx.de>
 
 	* java/net/NetPermission.java
 	(NetPermission): Make doucmentation match the method declaration.

libjava/Makefile.am

@@ -1855,6 +1855,15 @@ java/util/TreeSet.java \
 java/util/TooManyListenersException.java \
 java/util/Vector.java \
 java/util/WeakHashMap.java \
+java/util/prefs/NodeChangeListener.java \
+java/util/prefs/Preferences.java \
+java/util/prefs/PreferenceChangeListener.java \
+java/util/prefs/NodeChangeEvent.java \
+java/util/prefs/InvalidPreferencesFormatException.java \
+java/util/prefs/AbstractPreferences.java \
+java/util/prefs/BackingStoreException.java \
+java/util/prefs/PreferenceChangeEvent.java \
+java/util/prefs/PreferencesFactory.java \
 java/util/regex/Matcher.java \
 java/util/regex/Pattern.java \
 java/util/regex/PatternSyntaxException.java
@@ -2075,6 +2084,11 @@ gnu/java/text/SentenceBreakIterator.java \
 gnu/java/text/WordBreakIterator.java \
 gnu/java/util/DoubleEnumeration.java \
 gnu/java/util/EmptyEnumeration.java \
+gnu/java/util/prefs/MemoryBasedFactory.java \
+gnu/java/util/prefs/NodeReader.java \
+gnu/java/util/prefs/MemoryBasedPreferences.java \
+gnu/java/util/prefs/FileBasedFactory.java \
+gnu/java/util/prefs/NodeWriter.java \
 java/lang/ref/PhantomReference.java \
 java/lang/ref/Reference.java \
 java/lang/ref/ReferenceQueue.java \

libjava/Makefile.in

@@ -1620,6 +1620,15 @@ java/util/TreeSet.java \
 java/util/TooManyListenersException.java \
 java/util/Vector.java \
 java/util/WeakHashMap.java \
+java/util/prefs/NodeChangeListener.java \
+java/util/prefs/Preferences.java \
+java/util/prefs/PreferenceChangeListener.java \
+java/util/prefs/NodeChangeEvent.java \
+java/util/prefs/InvalidPreferencesFormatException.java \
+java/util/prefs/AbstractPreferences.java \
+java/util/prefs/BackingStoreException.java \
+java/util/prefs/PreferenceChangeEvent.java \
+java/util/prefs/PreferencesFactory.java \
 java/util/regex/Matcher.java \
 java/util/regex/Pattern.java \
 java/util/regex/PatternSyntaxException.java
@@ -1835,6 +1844,11 @@ gnu/java/text/SentenceBreakIterator.java \
 gnu/java/text/WordBreakIterator.java \
 gnu/java/util/DoubleEnumeration.java \
 gnu/java/util/EmptyEnumeration.java \
+gnu/java/util/prefs/MemoryBasedFactory.java \
+gnu/java/util/prefs/NodeReader.java \
+gnu/java/util/prefs/MemoryBasedPreferences.java \
+gnu/java/util/prefs/FileBasedFactory.java \
+gnu/java/util/prefs/NodeWriter.java \
 java/lang/ref/PhantomReference.java \
 java/lang/ref/Reference.java \
 java/lang/ref/ReferenceQueue.java \
@@ -2912,7 +2926,12 @@ DEP_FILES =  .deps/$(srcdir)/$(CONVERT_DIR)/gen-from-JIS.P \
 .deps/gnu/java/text/SentenceBreakIterator.P \
 .deps/gnu/java/text/WordBreakIterator.P \
 .deps/gnu/java/util/DoubleEnumeration.P \
-.deps/gnu/java/util/EmptyEnumeration.P .deps/interpret.P \
+.deps/gnu/java/util/EmptyEnumeration.P \
+.deps/gnu/java/util/prefs/FileBasedFactory.P \
+.deps/gnu/java/util/prefs/MemoryBasedFactory.P \
+.deps/gnu/java/util/prefs/MemoryBasedPreferences.P \
+.deps/gnu/java/util/prefs/NodeReader.P \
+.deps/gnu/java/util/prefs/NodeWriter.P .deps/interpret.P \
 .deps/java/applet/Applet.P .deps/java/applet/AppletContext.P \
 .deps/java/applet/AppletStub.P .deps/java/applet/AudioClip.P \
 .deps/java/awt/AWTError.P .deps/java/awt/AWTEvent.P \
@@ -3604,6 +3623,15 @@ DEP_FILES =  .deps/$(srcdir)/$(CONVERT_DIR)/gen-from-JIS.P \
 .deps/java/util/jar/JarInputStream.P \
 .deps/java/util/jar/JarOutputStream.P .deps/java/util/jar/Manifest.P \
 .deps/java/util/natResourceBundle.P .deps/java/util/natTimeZone.P \
+.deps/java/util/prefs/AbstractPreferences.P \
+.deps/java/util/prefs/BackingStoreException.P \
+.deps/java/util/prefs/InvalidPreferencesFormatException.P \
+.deps/java/util/prefs/NodeChangeEvent.P \
+.deps/java/util/prefs/NodeChangeListener.P \
+.deps/java/util/prefs/PreferenceChangeEvent.P \
+.deps/java/util/prefs/PreferenceChangeListener.P \
+.deps/java/util/prefs/Preferences.P \
+.deps/java/util/prefs/PreferencesFactory.P \
 .deps/java/util/regex/Matcher.P .deps/java/util/regex/Pattern.P \
 .deps/java/util/regex/PatternSyntaxException.P \
 .deps/java/util/zip/Adler32.P .deps/java/util/zip/CRC32.P \

libjava/gnu/java/util/prefs/FileBasedFactory.java

+/* FileBasedFactory - Default Classpath implementation of a PreferencesFactory
+   Copyright (C) 2001 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.
+
+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.util.prefs;
+
+import java.util.prefs.*;
+
+/**
+ * Default Classpath implementation of a PreferencesFactory.
+ * Returns system and user root Preferences nodes that are read from files.
+ *
+ * @author Mark Wielaard (mark@klomp.org)
+ */
+public class FileBasedFactory implements PreferencesFactory {
+
+    public Preferences systemRoot() {
+        return null;
+    }
+
+    public Preferences userRoot() {
+        return null;
+    }
+}

libjava/gnu/java/util/prefs/MemoryBasedFactory.java

+/* MemoryBasedFactory - Memory based PreferencesFactory usefull for testing
+   Copyright (C) 2001 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.
+
+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.util.prefs;
+
+import java.util.prefs.*;
+
+/**
+ * Memory based PreferencesFactory usefull for testing.
+ * Returns completely empty Preferences for system and user roots.
+ * All changes are only backed by the current instances in memory.
+ *
+ * @author Mark Wielaard (mark@klomp.org)
+ */
+public class MemoryBasedFactory implements PreferencesFactory {
+
+    // Static fields containing the preferences root nodes
+    private static final Preferences systemPreferences
+        = new MemoryBasedPreferences(null, "", false);
+    private static final Preferences userPreferences
+        = new MemoryBasedPreferences(null, "", true);
+
+    public Preferences systemRoot() {
+        return systemPreferences;
+    }
+
+    public Preferences userRoot() {
+        return userPreferences;
+    }
+}

libjava/gnu/java/util/prefs/MemoryBasedPreferences.java

+/* MemoryBasedPreferences - A Preference node which holds all entries in memory
+   Copyright (C) 2001 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.
+
+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.util.prefs;
+
+import java.util.HashMap;
+
+import java.util.prefs.*;
+
+/**
+ * A Preference node which holds all entries in memory
+ *
+ * @author Mark Wielaard (mark@klomp.org)
+ */
+public class MemoryBasedPreferences extends AbstractPreferences {
+
+    /** True if this is a preference node in the user tree, false otherwise. */
+    private final boolean isUser;
+
+    /** Contains all the preference entries of this node. */
+    private HashMap entries = new HashMap();
+
+    /**
+     * Creates a new preferences node with the given name and parent.
+     * When isUser is true it will be user node otherwise it will be a system
+     * node. It will always set the <code>newNode</code> field to true
+     * since there is no real backing store, so all nodes are new.
+     */
+    public MemoryBasedPreferences(MemoryBasedPreferences parent,
+                                  String name,
+                                  boolean isUser) {
+        super(parent, name);
+        this.isUser = isUser;
+
+        // Since we do not have a real backing store all nodes are new
+        newNode = true;
+    }
+
+    /**
+     * Returns true if this node was created as a user node.
+     */
+    public boolean isUserNode() {
+        return isUser;
+    }
+
+    /**
+     * Returns an empty array since all children names are always already
+     * chached.
+     */
+    protected String[] childrenNamesSpi() throws BackingStoreException {
+        return new String[0];
+    }
+
+    /**
+     * Returns a new node with the given name with as parent this node and
+     * with the <code>isUser</code> flag set to the same value as this node.
+     */
+    protected AbstractPreferences childSpi(String childName) {
+       return new MemoryBasedPreferences(this, childName, isUser);
+    }
+
+    /**
+     * Returns a (possibly empty) array of keys of the preferences entries of
+     * this node.
+     */
+    protected String[] keysSpi() throws BackingStoreException {
+        return (String[]) entries.keySet().toArray(new String[entries.size()]);
+    }
+
+    /**
+     * Returns the associated value from this nodes preferences entries or
+     * null when the key has not been set.
+     */
+    protected String getSpi(String key) {
+        return (String) entries.get(key);
+    }
+
+    /**
+     * Sets the value for the given key.
+     */
+    protected void putSpi(String key, String value) {
+        entries.put(key, value);
+    }
+
+    /**
+     * Removes the entry with the given key.
+     */
+    protected void removeSpi(String key) {
+        entries.remove(key);
+    }
+
+    /**
+     * Does nothing since we do not have any backing store.
+     */
+    protected void flushSpi() {
+    }
+
+    /**
+     * Does nothing since we do not have any backing store.
+     */
+    protected void syncSpi() {
+    }
+
+    /**
+     * Just removes the entries map of this node.
+     */
+    protected void removeNodeSpi() {
+        entries = null;
+    }
+}

libjava/gnu/java/util/prefs/NodeReader.java

+/* NodeReader - Reads and imports preferences nodes from files
+   Copyright (C) 2001 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.
+
+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.util.prefs;
+
+import java.io.BufferedReader;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.InputStream;
+import java.io.IOException;
+import java.io.Reader;
+
+import java.util.prefs.*;
+
+/**
+ * Reads and imports preferences nodes from files.
+ *
+ * @author Mark Wielaard (mark@klomp.org)
+ */
+public class NodeReader {
+
+    private final BufferedReader br;
+    private String line = "";
+
+    private final PreferencesFactory factory;
+
+    public NodeReader(Reader r, PreferencesFactory factory) {
+        if(r instanceof BufferedReader) {
+            br = (BufferedReader) r;
+        } else {
+            br = new BufferedReader(r);
+        }
+        this.factory = factory;
+    }
+
+    public NodeReader(InputStream is, PreferencesFactory factory) {
+        this(new InputStreamReader(is), factory);
+    }
+
+    public void importPreferences()
+                    throws InvalidPreferencesFormatException, IOException
+    {
+        readPreferences();
+    }
+
+    private void readPreferences()
+                    throws InvalidPreferencesFormatException, IOException
+    {
+        // Begin starting tag
+        skipTill("<preferences");
+
+        readRoot();
+
+        // Ending tag
+        skipTill("</preferences>");
+    }
+
+    private void readRoot()
+                    throws InvalidPreferencesFormatException, IOException
+    {
+        // Begin starting tag
+        skipTill("<root");
+
+        // type attribute
+        skipTill("type=\"");
+        String type = readTill("\"");
+        Preferences root;
+        if ("user".equals(type)) {
+            root = factory.userRoot();
+        } else if ("system".equals(type)) {
+            root = factory.systemRoot();
+        } else {
+            throw new InvalidPreferencesFormatException("Unknown type: "
+                                                        + type);
+        }
+
+        // Read root map and subnodes
+        readMap(root);
+        readNodes(root);
+
+        // Ending tag
+        skipTill("</root>");
+    }
+
+    private void readNodes(Preferences node)
+                    throws InvalidPreferencesFormatException, IOException
+    {
+        while ("node".equals(nextTag())) {
+            skipTill("<node");
+            skipTill("name=\"");
+            String name = readTill("\"");
+            Preferences subnode = node.node(name);
+            System.out.println("Found subnode: " + subnode.absolutePath());
+            readMap(subnode);
+            readNodes(subnode);
+            skipTill("</node>");
+        }
+        
+    }
+
+    private void readMap(Preferences node)
+                    throws InvalidPreferencesFormatException, IOException
+    {
+        // Begin map tag
+        skipTill("<map");
+
+        // Empty map?
+        if (line.startsWith("/>")) {
+            line = line.substring(2);
+            return;
+        }
+
+        // Map entries
+        readEntries(node);
+
+        // Ending tag
+        skipTill("</map>");
+    }
+
+    private void readEntries(Preferences node)
+                    throws InvalidPreferencesFormatException, IOException
+    {
+        while ("entry".equals(nextTag())) {
+            skipTill("<entry");
+            skipTill("key=\"");
+            String key = readTill("\"");
+            skipTill("value=\"");
+            String value = readTill("\"");
+            System.out.println("Key: " + key + " Value: " + value);
+            node.put(key, value);
+        }
+    }
+
+    private void skipTill(String s)
+                    throws InvalidPreferencesFormatException, IOException
+    {
+        while(true) {
+            if (line == null)
+                throw new InvalidPreferencesFormatException(s + " not found");
+            
+            int index = line.indexOf(s);
+            if (index == -1)  {
+                line = br.readLine();
+            } else {
+                line = line.substring(index+s.length());
+                return;
+            }
+        }
+    }
+
+    private String readTill(String s)
+                    throws InvalidPreferencesFormatException
+    {
+        int index = line.indexOf(s);
+        if (index == -1)
+                throw new InvalidPreferencesFormatException(s + " not found");
+
+        String read = line.substring(0, index);
+        line = line.substring(index+s.length());
+
+        return read;
+    }
+
+    private String nextTag()
+                    throws InvalidPreferencesFormatException, IOException
+    {
+        while(true) {
+            if (line == null)
+                throw new InvalidPreferencesFormatException("unexpected EOF");
+            
+            int start = line.indexOf("<");
+            if (start == -1)  {
+                line = br.readLine();
+            } else {
+                // Find end of tag
+                int end = start+1;
+                while (end != line.length()
+                       && " \t\r\n".indexOf(line.charAt(end)) == -1) {
+                    end++;
+                }
+                // Line now starts at the found tag
+                String tag = line.substring(start+1,end);
+                line = line.substring(start);
+                return tag;
+            }
+        }
+    }
+
+}

libjava/gnu/java/util/prefs/NodeWriter.java

+/* NodeWriter - Writes and exports preferences nodes to files
+   Copyright (C) 2001 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.
+
+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.util.prefs;
+
+import java.io.BufferedWriter;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.io.OutputStreamWriter;
+import java.io.Writer;
+
+import java.util.StringTokenizer;
+
+import java.util.prefs.*;
+
+/**
+ * Writes and exports preferences nodes to files
+ *
+ * @author Mark Wielaard (mark@klomp.org)
+ */
+public class NodeWriter {
+
+    /** The Preferences node to write. */
+    private final Preferences prefs;
+
+    /** The bufferedWriter to write the node to. */
+    private final BufferedWriter bw;
+
+    /**
+     * True if the complete sub tree should be written,
+     * false if only the node should be written.
+     */
+    private boolean subtree;
+
+    /**
+     * Creates a new NodeWriter for the given preferences node and writer.
+     */
+    public NodeWriter(Preferences prefs, Writer w) {
+        this.prefs = prefs;
+        if (w instanceof BufferedWriter) {
+            this.bw = (BufferedWriter) w;
+        } else {
+            this.bw = new BufferedWriter(w);
+        }
+    }
+
+    /**
+     * Creates a new NodeWriter for the given preferences node and
+     * outputstream. Creates a new OutputStreamWriter.
+     */
+    public NodeWriter(Preferences prefs, OutputStream os) {
+        this(prefs, new OutputStreamWriter(os));
+    }
+
+    /**
+     * Writes the preference node plus the complete subtree.
+     */
+    public void writePrefsTree() throws BackingStoreException, IOException {
+        subtree = true;
+        writeHeader();
+        writePreferences();
+        bw.flush();
+    }
+
+    /**
+     * Writes only the preference node.
+     */
+    public void writePrefs() throws BackingStoreException, IOException {
+        subtree = false;
+        writeHeader();
+        writePreferences();
+        bw.flush();
+    }
+
+    /**
+     * Writes the standard header.
+     */
+    private void writeHeader() throws BackingStoreException, IOException {
+        bw.write("<?xml version=\"1.0\"?>");
+        bw.newLine();
+        bw.newLine();
+        bw.write("<!-- GNU Classpath java.util.prefs Preferences ");
+
+        if (prefs.isUserNode()) {
+            bw.write("user");
+        } else {
+            bw.write("system");
+        }
+
+        // root node?
+        if (prefs.parent() == null) {
+            bw.write(" root");
+        }
+
+        if (subtree) {
+            bw.write(" tree");
+        } else {
+            bw.write(" node");
+        }
+
+        // no root?
+        if (prefs.parent() != null) {
+            bw.newLine();
+            bw.write("     '");
+            bw.write(prefs.absolutePath());
+            bw.write('\'');
+            bw.newLine();
+        }
+        bw.write(" -->");
+        bw.newLine();
+        bw.newLine();
+    }
+
+    /**
+     * Write the preferences tag and the root.
+     */
+    private void writePreferences() throws BackingStoreException, IOException {
+        bw.write("<preferences>");
+        bw.newLine();
+        writeRoot();
+        bw.write("</preferences>");
+        bw.newLine();
+    }
+
+    private void writeRoot() throws BackingStoreException, IOException {
+        bw.write("  <root type=\"");
+        if (prefs.isUserNode()) {
+            bw.write("user");
+        } else {
+            bw.write("system");
+        }
+        bw.write("\"/>");
+
+        writeRootMap();
+        writeNode();
+
+        bw.write("  </root>");
+        bw.newLine();
+    }
+
+    private void writeRootMap() throws BackingStoreException, IOException {
+        // Is it a root node?
+        if(prefs.parent() == null && prefs.keys().length > 0) {
+            bw.newLine();
+            writeMap(prefs, 2);
+        } else {
+            bw.write("<map/>");
+            bw.newLine();
+        }
+    }
+
+    /**
+     * Writes all the parents of the preferences node without any entries.
+     * Returns the number of parents written, which has to be used as
+     * argument to <code>writeCloseParents()</code> after writing the node
+     * itself.
+     */
+    private int writeParents() throws IOException {
+        int parents;
+        String path = prefs.absolutePath();
+        int lastslash = path.lastIndexOf("/");
+        if (lastslash > 0) {
+            path = path.substring(1, lastslash);
+            StringTokenizer st = new StringTokenizer(path);
+            parents = st.countTokens();
+
+            System.out.println("path: " + path);
+            System.out.println("parents: " + parents);
+
+            for (int i=0; i<parents; i++) {
+                String name = st.nextToken();
+                indent(i+2);
+                bw.write("<node name=\"" + name + "\">");
+                bw.write("<map/>");
+                bw.write("</node>");
+                bw.newLine();
+            }
+        } else {
+            parents = 0;
+        }
+
+        return parents;
+    }
+
+    private void writeCloseParents(int parents) throws IOException {
+        while(parents > 0) {
+            indent(parents+1);
+            bw.write("</node>");
+            bw.newLine();
+            parents--;
+        }
+    }
+
+    private void writeNode() throws BackingStoreException, IOException {
+        int parents = writeParents();
+        // root?
+        int indent;
+        if (prefs.parent() == null) {
+            indent = parents+1;
+        } else {
+            indent = parents+2;
+        }
+        writeNode(prefs, indent);
+        writeCloseParents(parents);
+    }
+
+    private void writeNode(Preferences node, int indent)
+                                    throws BackingStoreException, IOException
+    {
+        // not root?
+        if (node.parent() != null) {
+            indent(indent);
+            bw.write("<node name=\"" + node.name() + "\">");
+            if (node.keys().length > 0) {
+                bw.newLine();
+            }
+            writeMap(node, indent+1);
+        }
+
+        if (subtree) {
+            String[] children = node.childrenNames();
+            for (int i=0; i<children.length; i++) {
+                Preferences child = node.node(children[i]);
+                writeNode(child, indent+1);
+            }
+        }
+
+        // not root?
+        if (node.parent() != null) {
+            indent(indent);
+            bw.write("</node>");
+            bw.newLine();
+        }
+    }
+
+    private void writeMap(Preferences node, int indent) 
+                                    throws BackingStoreException, IOException
+    {
+        // construct String used for indentation
+        StringBuffer indentBuffer = new StringBuffer(2*indent);
+        for (int i=0; i < indent; i++)
+            indentBuffer.append("  ");
+        String indentString = indentBuffer.toString();
+
+        if (node.keys().length > 0) {
+            bw.write(indentString);
+            bw.write("<map>");
+            bw.newLine();
+            writeEntries(node, indentString + "  ");
+            bw.write(indentString);
+            bw.write("</map>");
+        } else {
+            bw.write("<map/>");
+        }
+        bw.newLine();
+    }
+
+    private void writeEntries(Preferences node, String indent)
+                                    throws BackingStoreException, IOException
+    {
+        String[] keys = node.keys();
+        for(int i = 0; i < keys.length; i++) {
+            String value = node.get(keys[i], null);
+            if (value == null) {
+                throw new BackingStoreException("null value for key '"
+                                                + keys[i] + "'");
+            }
+
+            bw.write(indent);
+            bw.write("<entry key=\"" + keys[i] + "\""
+                    + " value=\"" + value + "\"/>");
+            bw.newLine();
+        }
+    }
+
+    private void indent(int x) throws IOException {
+        for (int i=0; i<x; i++) {
+            bw.write("  ");
+        }
+    }
+}

libjava/java/util/prefs/BackingStoreException.java

+/* BackingStoreException.java - chained exception thrown when backing store
+   fails
+   Copyright (C) 2001, 2002 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.
+
+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.util.prefs;
+
+import java.io.ObjectOutputStream;
+import java.io.ObjectInputStream;
+import java.io.NotSerializableException;
+
+/**
+ * Chained exception thrown when backing store fails. This exception is
+ * only thrown from methods that actually have to access the backing store,
+ * such as <code>clear(), keys(), childrenNames(), nodeExists(), removeNode(),
+ * flush(), sync(), exportNode(), exportSubTree()</code>; normal operations
+ * do not throw BackingStoreExceptions.
+ *
+ * <p>Note that although this class inherits the Serializable interface, an
+ * attempt to serialize will fail with a <code>NotSerializableException</code>.
+ *
+ * @author Mark Wielaard <mark@klomp.org>
+ * @since 1.4
+ * @status updated to 1.4
+ */
+public class BackingStoreException extends Exception
+{
+  static final long serialVersionUID = 859796500401108469L;
+
+  /**
+   * Creates a new exception with a descriptive message.
+   *
+   * @param message the message
+   */
+  public BackingStoreException(String message)
+  {
+    super(message);
+  }
+
+  /**
+   * Create a new exception with the given cause.
+   *
+   * @param cause the cause
+   */
+  public BackingStoreException(Throwable cause)
+  {
+    super(cause);
+  }
+
+  /**
+   * This class should not be serialized.
+   *
+   * @param o the output stream
+   */
+  private void writeObject(ObjectOutputStream o) throws NotSerializableException
+  {
+    throw new NotSerializableException
+      ("java.util.prefs.BackingStoreException");
+  }
+
+  /**
+   * This class should not be serialized.
+   *
+   * @param i the input stream
+   */
+  private void readObject(ObjectInputStream i) throws NotSerializableException
+  {
+    throw new NotSerializableException
+      ("java.util.prefs.BackingStoreException");
+  }
+}

libjava/java/util/prefs/InvalidPreferencesFormatException.java

+/* InvalidPreferencesFormatException - indicates reading prefs from stream
+   failed
+   Copyright (C) 2001, 2002 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.
+
+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.util.prefs;
+
+import java.io.ObjectOutputStream;
+import java.io.ObjectInputStream;
+import java.io.NotSerializableException;
+
+/**
+ * Indicates reading prefs from stream failed. Thrown by the
+ * <code>importPreferences()</code> method when the supplied input stream
+ * could not be read because it was not in the correct XML format.
+ *
+ * <p>Note that although this class inherits the Serializable interface, an
+ * attempt to serialize will fail with a <code>NotSerializableException</code>.
+ *
+ * @author Mark Wielaard <mark@klomp.org>
+ * @see Preferences
+ * @since 1.4
+ * @status updated to 1.4
+ */
+public class InvalidPreferencesFormatException extends Exception
+{
+  static final long serialVersionUID = -791715184232119669L;
+
+  /**
+   * Creates a new exception with a descriptive message. The cause remains
+   * uninitialized.
+   *
+   * @param message the message
+   */
+  public InvalidPreferencesFormatException(String message)
+  {
+    super(message);
+  }
+
+  /**
+   * Creates a new exception with the given cause.
+   *
+   * @param cause the cause
+   */
+  public InvalidPreferencesFormatException(Throwable cause)
+  {
+    super(cause);
+  }
+
+  /**
+   * Creates a new exception with a descriptive message and a cause.
+   *
+   * @param message the message
+   * @param cause the cause
+   */
+  public InvalidPreferencesFormatException(String message, Throwable cause)
+  {
+    super(message, cause);
+  }
+
+  /**
+   * This class should not be serialized.
+   *
+   * @param o the output stream
+   */
+  private void writeObject(ObjectOutputStream o) throws NotSerializableException
+  {
+    throw new NotSerializableException
+      ("java.util.prefs.InvalidPreferencesFormatException");
+  }
+
+  /**
+   * This class should not be serialized.
+   *
+   * @param i the input stream
+   */
+  private void readObject(ObjectInputStream i) throws NotSerializableException
+  {
+    throw new NotSerializableException
+      ("java.util.prefs.InvalidPreferencesFormatException");
+  }
+}

libjava/java/util/prefs/NodeChangeEvent.java

+/* NodeChangeEvent - ObjectEvent fired when a Preference node is added/removed
+   Copyright (C) 2001 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.
+
+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.util.prefs;
+
+import java.util.EventObject;
+
+/**
+ * ObjectEvent fired when a Preference node is added/removed.
+ * This event is only generated when a new subnode is added or a subnode is
+ * removed from a preference node. Changes in the entries of a preference node
+ * are indicated with a <code>PreferenceChangeEvent</code>.
+ *
+ * @since 1.4
+ * @author Mark Wielaard (mark@klomp.org)
+ */
+public class NodeChangeEvent extends EventObject {
+
+  private static final long serialVersionUID =8068949086596572957L; 
+  
+    /**
+     * The sub node that was added or removed.
+     * Defined transient just like <code>EventObject.source</code> since
+     * this object should be serializable, but Preferences is in general not
+     * serializable.
+     */
+    private final transient Preferences child;
+
+    /**
+     * Creates a new NodeChangeEvent.
+     *
+     * @param parentNode The source preference node from which a subnode was
+     * added or removed
+     * @param childNode The preference node that was added or removed
+     */
+    public NodeChangeEvent(Preferences parentNode, Preferences childNode) {
+        super(parentNode);
+        child = childNode;
+    }
+
+    /**
+     * Returns the source parent preference node from which a subnode was
+     * added or removed.
+     */
+    public Preferences getParent() {
+        return (Preferences) source;
+    }
+
+    /**
+     * Returns the child preference subnode that was added or removed.
+     * To see wether it is still a valid preference node one has to call
+     * <code>event.getChild().nodeExists("")</code>.
+     */
+    public Preferences getChild() {
+        return child;
+    }
+}

libjava/java/util/prefs/NodeChangeListener.java

+/* NodeChangeListener - EventListener for Preferences node addition/removal
+   Copyright (C) 2001 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.
+
+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.util.prefs;
+
+import java.util.EventListener;
+
+/**
+ * EventListener for Preferences node addition/removal.
+ * <p>
+ * Note that these events are only generated for the addition and removal
+ * of sub nodes from the preference node. Entry changes in the preference
+ * node can be monitored with a <code>PreferenceChangeListener</code>.
+ *
+ * @since 1.4
+ * @author Mark Wielaard (mark@klomp.org)
+ */
+public interface NodeChangeListener extends EventListener {
+
+    /**
+     * Fired when a sub node is added to the preference node.
+     */
+    void childAdded(NodeChangeEvent event);
+
+    /**
+     * Fired when a sub node is removed from the preference node.
+     */
+    void childRemoved(NodeChangeEvent event);
+
+}

libjava/java/util/prefs/PreferenceChangeEvent.java

+/* PreferenceChangeEvent - ObjectEvent fired when a Preferences entry changes
+   Copyright (C) 2001 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.
+
+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.util.prefs;
+
+import java.util.EventObject;
+
+/**
+ * ObjectEvent fired when a Preferences entry changes.
+ * This event is generated when a entry is added, changed or removed.
+ * When an entry is removed then <code>getNewValue</code> will return null.
+ * <p>
+ * Preference change events are only generated for entries in one particular
+ * preference node. Notification of subnode addition/removal is given by a
+ * <code>NodeChangeEvent</code>.
+ *
+ * @since 1.4
+ * @author Mark Wielaard (mark@klomp.org)
+ */
+public class PreferenceChangeEvent extends EventObject {
+
+  private static final long serialVersionUID = 793724513368024975L;
+  
+    /**
+     * The key of the changed entry.
+     */
+    private final String key;
+
+    /**
+     * The new value of the changed entry, or null when the entry was removed.
+     */
+    private final String newValue;
+
+    /**
+     * Creates a new PreferenceChangeEvent.
+     *
+     * @param node The source preference node for which an entry was added,
+     * changed or removed
+     * @param key The key of the entry that was added, changed or removed
+     * @param value The new value of the entry that was added or changed, or
+     * null when the entry was removed
+     */
+    public PreferenceChangeEvent(Preferences node, String key, String value) {
+        super(node);
+        this.key = key;
+        this.newValue = value;
+    }
+
+    /**
+     * Returns the source Preference node from which an entry was added,
+     * changed or removed.
+     */
+    public Preferences getNode() {
+        return (Preferences) source;
+    }
+
+    /**
+     * Returns the key of the entry that was added, changed or removed.
+     */
+    public String getKey() {
+        return key;
+    }
+
+    /**
+     * Returns the new value of the entry that was added or changed, or
+     * returns null when the entry was removed.
+     */
+    public String getNewValue() {
+        return newValue;
+    }
+}

libjava/java/util/prefs/PreferenceChangeListener.java

+/* PreferenceChangeListener - EventListener for Preferences entry changes
+   Copyright (C) 2001 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.
+
+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.util.prefs;
+
+import java.util.EventListener;
+
+/**
+ * EventListener for Preferences entry addition, change or removal.
+ * <p>
+ * Preference change events are only generated for entries in one particular
+ * preference node. Notification of subnode addition/removal can be monitored
+ * with a <code>NodeChangeListener</code>.
+ *
+ * @since 1.4
+ * @author Mark Wielaard (mark@klomp.org)
+ */
+public interface PreferenceChangeListener extends EventListener {
+
+    /**
+     * Fired when a entry has been added, changed or removed from the
+     * preference node.
+     */
+    void preferenceChange(PreferenceChangeEvent event);
+
+}

libjava/java/util/prefs/PreferencesFactory.java

+/* PreferencesFactory - Preferences system and user root factory interface
+   Copyright (C) 2001 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.
+
+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.util.prefs;
+
+import java.util.EventListener;
+
+/**
+ * Preferences system and user root factory interface. Defines how to get
+ * to the system and user root preferences objects. Should be implemented by
+ * new preferences backends.
+ *
+ * @since 1.4
+ * @author Mark Wielaard (mark@klomp.org)
+ */
+public interface PreferencesFactory {
+
+    /**
+     * Returns the system root preferences node. Should always return the
+     * same object.
+     */
+    Preferences systemRoot();
+
+    /**
+     * Returns the user root preferences node. May return different objects
+     * depending on the user that called this method. The user may for example
+     * be determined by the current Thread or the Subject associated with the
+     * current AccessControllContext.
+     */
+    Preferences userRoot();
+
+}