| /* AbstractPreferences -- Partial implementation of a Preference node |
| Copyright (C) 2001, 2003, 2004, 2006 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.util.prefs; |
| |
| import gnu.java.util.prefs.EventDispatcher; |
| import gnu.java.util.prefs.NodeWriter; |
| |
| import java.io.ByteArrayOutputStream; |
| import java.io.IOException; |
| import java.io.OutputStream; |
| import java.util.ArrayList; |
| import java.util.HashMap; |
| import java.util.Iterator; |
| import java.util.TreeSet; |
| |
| /** |
| * Partial implementation of a Preference node. |
| * |
| * @since 1.4 |
| * @author Mark Wielaard (mark@klomp.org) |
| */ |
| public abstract class AbstractPreferences extends Preferences { |
| |
| // protected fields |
| |
| /** |
| * Object used to lock this preference node. Any thread only locks nodes |
| * downwards when it has the lock on the current node. No method should |
| * synchronize on the lock of any of its parent nodes while holding the |
| * lock on the current node. |
| */ |
| protected final Object lock = new Object(); |
| |
| /** |
| * Set to true in the contructor if the node did not exist in the backing |
| * store when this preference node object was created. Should be set in |
| * the constructor of a subclass. Defaults to false. Used to fire node |
| * changed events. |
| */ |
| protected boolean newNode = false; |
| |
| // private fields |
| |
| /** |
| * The parent preferences node or null when this is the root node. |
| */ |
| private final AbstractPreferences parent; |
| |
| /** |
| * The name of this node. |
| * Only when this is a root node (parent == null) the name is empty. |
| * It has a maximum of 80 characters and cannot contain any '/' characters. |
| */ |
| private final String name; |
| |
| /** True when this node has been remove, false otherwise. */ |
| private boolean removed = false; |
| |
| /** |
| * Holds all the child names and nodes of this node that have been |
| * accessed by earlier <code>getChild()</code> or <code>childSpi()</code> |
| * invocations and that have not been removed. |
| */ |
| private HashMap childCache = new HashMap(); |
| |
| /** |
| * A list of all the registered NodeChangeListener objects. |
| */ |
| private ArrayList nodeListeners; |
| |
| /** |
| * A list of all the registered PreferenceChangeListener objects. |
| */ |
| private ArrayList preferenceListeners; |
| |
| // constructor |
| |
| /** |
| * Creates a new AbstractPreferences node with the given parent and name. |
| * |
| * @param parent the parent of this node or null when this is the root node |
| * @param name the name of this node, can not be null, only 80 characters |
| * maximum, must be empty when parent is null and cannot |
| * contain any '/' characters |
| * @exception IllegalArgumentException when name is null, greater then 80 |
| * characters, not the empty string but parent is null or |
| * contains a '/' character |
| */ |
| protected AbstractPreferences(AbstractPreferences parent, String name) { |
| if ( (name == null) // name should be given |
| || (name.length() > MAX_NAME_LENGTH) // 80 characters max |
| || (parent == null && name.length() != 0) // root has no name |
| || (parent != null && name.length() == 0) // all other nodes do |
| || (name.indexOf('/') != -1)) // must not contain '/' |
| throw new IllegalArgumentException("Illegal name argument '" |
| + name |
| + "' (parent is " |
| + (parent == null ? "" : "not ") |
| + "null)"); |
| this.parent = parent; |
| this.name = name; |
| } |
| |
| // identification methods |
| |
| /** |
| * Returns the absolute path name of this preference node. |
| * The absolute path name of a node is the path name of its parent node |
| * plus a '/' plus its own name. If the node is the root node and has no |
| * parent then its path name is "" and its absolute path name is "/". |
| */ |
| public String absolutePath() { |
| if (parent == null) |
| return "/"; |
| else |
| return parent.path() + '/' + name; |
| } |
| |
| /** |
| * Private helper method for absolutePath. Returns the empty string for a |
| * root node and otherwise the parentPath of its parent plus a '/'. |
| */ |
| private String path() { |
| if (parent == null) |
| return ""; |
| else |
| return parent.path() + '/' + name; |
| } |
| |
| /** |
| * Returns true if this node comes from the user preferences tree, false |
| * if it comes from the system preferences tree. |
| */ |
| public boolean isUserNode() { |
| AbstractPreferences root = this; |
| while (root.parent != null) |
| root = root.parent; |
| return root == Preferences.userRoot(); |
| } |
| |
| /** |
| * Returns the name of this preferences node. The name of the node cannot |
| * be null, can be mostly 80 characters and cannot contain any '/' |
| * characters. The root node has as name "". |
| */ |
| public String name() { |
| return name; |
| } |
| |
| /** |
| * Returns the String given by |
| * <code> |
| * (isUserNode() ? "User":"System") + " Preference Node: " + absolutePath() |
| * </code> |
| */ |
| public String toString() { |
| return (isUserNode() ? "User":"System") |
| + " Preference Node: " |
| + absolutePath(); |
| } |
| |
| /** |
| * Returns all known unremoved children of this node. |
| * |
| * @return All known unremoved children of this node |
| */ |
| protected final AbstractPreferences[] cachedChildren() |
| { |
| return (AbstractPreferences[]) childCache.values().toArray(); |
| } |
| |
| /** |
| * Returns all the direct sub nodes of this preferences node. |
| * Needs access to the backing store to give a meaningfull answer. |
| * <p> |
| * This implementation locks this node, checks if the node has not yet |
| * been removed and throws an <code>IllegalStateException</code> when it |
| * has been. Then it creates a new <code>TreeSet</code> and adds any |
| * already cached child nodes names. To get any uncached names it calls |
| * <code>childrenNamesSpi()</code> and adds the result to the set. Finally |
| * it calls <code>toArray()</code> on the created set. When the call to |
| * <code>childrenNamesSpi</code> thows an <code>BackingStoreException</code> |
| * this method will not catch that exception but propagate the exception |
| * to the caller. |
| * |
| * @exception BackingStoreException when the backing store cannot be |
| * reached |
| * @exception IllegalStateException when this node has been removed |
| */ |
| public String[] childrenNames() throws BackingStoreException { |
| synchronized(lock) { |
| if (isRemoved()) |
| throw new IllegalStateException("Node removed"); |
| |
| TreeSet childrenNames = new TreeSet(); |
| |
| // First get all cached node names |
| childrenNames.addAll(childCache.keySet()); |
| |
| // Then add any others |
| String names[] = childrenNamesSpi(); |
| for (int i = 0; i < names.length; i++) { |
| childrenNames.add(names[i]); |
| } |
| |
| // And return the array of names |
| String[] children = new String[childrenNames.size()]; |
| childrenNames.toArray(children); |
| return children; |
| |
| } |
| } |
| |
| /** |
| * Returns a sub node of this preferences node if the given path is |
| * relative (does not start with a '/') or a sub node of the root |
| * if the path is absolute (does start with a '/'). |
| * <p> |
| * This method first locks this node and checks if the node has not been |
| * removed, if it has been removed it throws an exception. Then if the |
| * path is relative (does not start with a '/') it checks if the path is |
| * legal (does not end with a '/' and has no consecutive '/' characters). |
| * Then it recursively gets a name from the path, gets the child node |
| * from the child-cache of this node or calls the <code>childSpi()</code> |
| * method to create a new child sub node. This is done recursively on the |
| * newly created sub node with the rest of the path till the path is empty. |
| * If the path is absolute (starts with a '/') the lock on this node is |
| * droped and this method is called on the root of the preferences tree |
| * with as argument the complete path minus the first '/'. |
| * |
| * @exception IllegalStateException if this node has been removed |
| * @exception IllegalArgumentException if the path contains two or more |
| * consecutive '/' characters, ends with a '/' charactor and is not the |
| * string "/" (indicating the root node) or any name on the path is more |
| * than 80 characters long |
| */ |
| public Preferences node(String path) { |
| synchronized(lock) { |
| if (isRemoved()) |
| throw new IllegalStateException("Node removed"); |
| |
| // Is it a relative path? |
| if (!path.startsWith("/")) { |
| |
| // Check if it is a valid path |
| if (path.indexOf("//") != -1 || path.endsWith("/")) |
| throw new IllegalArgumentException(path); |
| |
| return getNode(path); |
| } |
| } |
| |
| // path started with a '/' so it is absolute |
| // we drop the lock and start from the root (omitting the first '/') |
| Preferences root = isUserNode() ? userRoot() : systemRoot(); |
| return root.node(path.substring(1)); |
| |
| } |
| |
| /** |
| * Private helper method for <code>node()</code>. Called with this node |
| * locked. Returns this node when path is the empty string, if it is not |
| * empty the next node name is taken from the path (all chars till the |
| * next '/' or end of path string) and the node is either taken from the |
| * child-cache of this node or the <code>childSpi()</code> method is called |
| * on this node with the name as argument. Then this method is called |
| * recursively on the just constructed child node with the rest of the |
| * path. |
| * |
| * @param path should not end with a '/' character and should not contain |
| * consecutive '/' characters |
| * @exception IllegalArgumentException if path begins with a name that is |
| * larger then 80 characters. |
| */ |
| private Preferences getNode(String path) { |
| // if mark is dom then goto end |
| |
| // Empty String "" indicates this node |
| if (path.length() == 0) |
| return this; |
| |
| // Calculate child name and rest of path |
| String childName; |
| String childPath; |
| int nextSlash = path.indexOf('/'); |
| if (nextSlash == -1) { |
| childName = path; |
| childPath = ""; |
| } else { |
| childName = path.substring(0, nextSlash); |
| childPath = path.substring(nextSlash+1); |
| } |
| |
| // Get the child node |
| AbstractPreferences child; |
| child = (AbstractPreferences)childCache.get(childName); |
| if (child == null) { |
| |
| if (childName.length() > MAX_NAME_LENGTH) |
| throw new IllegalArgumentException(childName); |
| |
| // Not in childCache yet so create a new sub node |
| child = childSpi(childName); |
| childCache.put(childName, child); |
| if (child.newNode && nodeListeners != null) |
| fire(new NodeChangeEvent(this, child), true); |
| } |
| |
| // Lock the child and go down |
| synchronized(child.lock) { |
| return child.getNode(childPath); |
| } |
| } |
| |
| /** |
| * Returns true if the node that the path points to exists in memory or |
| * in the backing store. Otherwise it returns false or an exception is |
| * thrown. When this node is removed the only valid parameter is the |
| * empty string (indicating this node), the return value in that case |
| * will be false. |
| * |
| * @exception BackingStoreException when the backing store cannot be |
| * reached |
| * @exception IllegalStateException if this node has been removed |
| * and the path is not the empty string (indicating this node) |
| * @exception IllegalArgumentException if the path contains two or more |
| * consecutive '/' characters, ends with a '/' charactor and is not the |
| * string "/" (indicating the root node) or any name on the path is more |
| * then 80 characters long |
| */ |
| public boolean nodeExists(String path) throws BackingStoreException { |
| synchronized(lock) { |
| if (isRemoved() && path.length() != 0) |
| throw new IllegalStateException("Node removed"); |
| |
| // Is it a relative path? |
| if (!path.startsWith("/")) { |
| |
| // Check if it is a valid path |
| if (path.indexOf("//") != -1 || path.endsWith("/")) |
| throw new IllegalArgumentException(path); |
| |
| return existsNode(path); |
| } |
| } |
| |
| // path started with a '/' so it is absolute |
| // we drop the lock and start from the root (omitting the first '/') |
| Preferences root = isUserNode() ? userRoot() : systemRoot(); |
| return root.nodeExists(path.substring(1)); |
| |
| } |
| |
| private boolean existsNode(String path) throws BackingStoreException { |
| |
| // Empty String "" indicates this node |
| if (path.length() == 0) |
| return(!isRemoved()); |
| |
| // Calculate child name and rest of path |
| String childName; |
| String childPath; |
| int nextSlash = path.indexOf('/'); |
| if (nextSlash == -1) { |
| childName = path; |
| childPath = ""; |
| } else { |
| childName = path.substring(0, nextSlash); |
| childPath = path.substring(nextSlash+1); |
| } |
| |
| // Get the child node |
| AbstractPreferences child; |
| child = (AbstractPreferences)childCache.get(childName); |
| if (child == null) { |
| |
| if (childName.length() > MAX_NAME_LENGTH) |
| throw new IllegalArgumentException(childName); |
| |
| // Not in childCache yet so create a new sub node |
| child = getChild(childName); |
| |
| if (child == null) |
| return false; |
| |
| childCache.put(childName, child); |
| } |
| |
| // Lock the child and go down |
| synchronized(child.lock) { |
| return child.existsNode(childPath); |
| } |
| } |
| |
| /** |
| * Returns the child sub node if it exists in the backing store or null |
| * if it does not exist. Called (indirectly) by <code>nodeExists()</code> |
| * when a child node name can not be found in the cache. |
| * <p> |
| * Gets the lock on this node, calls <code>childrenNamesSpi()</code> to |
| * get an array of all (possibly uncached) children and compares the |
| * given name with the names in the array. If the name is found in the |
| * array <code>childSpi()</code> is called to get an instance, otherwise |
| * null is returned. |
| * |
| * @exception BackingStoreException when the backing store cannot be |
| * reached |
| */ |
| protected AbstractPreferences getChild(String name) |
| throws BackingStoreException |
| { |
| synchronized(lock) { |
| // Get all the names (not yet in the cache) |
| String[] names = childrenNamesSpi(); |
| for (int i=0; i < names.length; i++) |
| if (name.equals(names[i])) |
| return childSpi(name); |
| |
| // No child with that name found |
| return null; |
| } |
| } |
| |
| /** |
| * Returns true if this node has been removed with the |
| * <code>removeNode()</code> method, false otherwise. |
| * <p> |
| * Gets the lock on this node and then returns a boolean field set by |
| * <code>removeNode</code> methods. |
| */ |
| protected boolean isRemoved() { |
| synchronized(lock) { |
| return removed; |
| } |
| } |
| |
| /** |
| * Returns the parent preferences node of this node or null if this is |
| * the root of the preferences tree. |
| * <p> |
| * Gets the lock on this node, checks that the node has not been removed |
| * and returns the parent given to the constructor. |
| * |
| * @exception IllegalStateException if this node has been removed |
| */ |
| public Preferences parent() { |
| synchronized(lock) { |
| if (isRemoved()) |
| throw new IllegalStateException("Node removed"); |
| |
| return parent; |
| } |
| } |
| |
| // export methods |
| |
| // Inherit javadoc. |
| public void exportNode(OutputStream os) |
| throws BackingStoreException, |
| IOException |
| { |
| NodeWriter nodeWriter = new NodeWriter(this, os); |
| nodeWriter.writePrefs(); |
| } |
| |
| // Inherit javadoc. |
| public void exportSubtree(OutputStream os) |
| throws BackingStoreException, |
| IOException |
| { |
| NodeWriter nodeWriter = new NodeWriter(this, os); |
| nodeWriter.writePrefsTree(); |
| } |
| |
| // preference entry manipulation methods |
| |
| /** |
| * Returns an (possibly empty) array with all the keys of the preference |
| * entries of this node. |
| * <p> |
| * This method locks this node and checks if the node has not been |
| * removed, if it has been removed it throws an exception, then it returns |
| * the result of calling <code>keysSpi()</code>. |
| * |
| * @exception BackingStoreException when the backing store cannot be |
| * reached |
| * @exception IllegalStateException if this node has been removed |
| */ |
| public String[] keys() throws BackingStoreException { |
| synchronized(lock) { |
| if (isRemoved()) |
| throw new IllegalStateException("Node removed"); |
| |
| return keysSpi(); |
| } |
| } |
| |
| |
| /** |
| * Returns the value associated with the key in this preferences node. If |
| * the default value of the key cannot be found in the preferences node |
| * entries or something goes wrong with the backing store the supplied |
| * default value is returned. |
| * <p> |
| * Checks that key is not null and not larger then 80 characters, |
| * locks this node, and checks that the node has not been removed. |
| * Then it calls <code>keySpi()</code> and returns |
| * the result of that method or the given default value if it returned |
| * null or throwed an exception. |
| * |
| * @exception IllegalArgumentException if key is larger then 80 characters |
| * @exception IllegalStateException if this node has been removed |
| * @exception NullPointerException if key is null |
| */ |
| public String get(String key, String defaultVal) { |
| if (key.length() > MAX_KEY_LENGTH) |
| throw new IllegalArgumentException(key); |
| |
| synchronized(lock) { |
| if (isRemoved()) |
| throw new IllegalStateException("Node removed"); |
| |
| String value; |
| try { |
| value = getSpi(key); |
| } catch (ThreadDeath death) { |
| throw death; |
| } catch (Throwable t) { |
| value = null; |
| } |
| |
| if (value != null) { |
| return value; |
| } else { |
| return defaultVal; |
| } |
| } |
| } |
| |
| /** |
| * Convenience method for getting the given entry as a boolean. |
| * When the string representation of the requested entry is either |
| * "true" or "false" (ignoring case) then that value is returned, |
| * otherwise the given default boolean value is returned. |
| * |
| * @exception IllegalArgumentException if key is larger then 80 characters |
| * @exception IllegalStateException if this node has been removed |
| * @exception NullPointerException if key is null |
| */ |
| public boolean getBoolean(String key, boolean defaultVal) { |
| String value = get(key, null); |
| |
| if ("true".equalsIgnoreCase(value)) |
| return true; |
| |
| if ("false".equalsIgnoreCase(value)) |
| return false; |
| |
| return defaultVal; |
| } |
| |
| /** |
| * Convenience method for getting the given entry as a byte array. |
| * When the string representation of the requested entry is a valid |
| * Base64 encoded string (without any other characters, such as newlines) |
| * then the decoded Base64 string is returned as byte array, |
| * otherwise the given default byte array value is returned. |
| * |
| * @exception IllegalArgumentException if key is larger then 80 characters |
| * @exception IllegalStateException if this node has been removed |
| * @exception NullPointerException if key is null |
| */ |
| public byte[] getByteArray(String key, byte[] defaultVal) { |
| String value = get(key, null); |
| |
| byte[] b = null; |
| if (value != null) { |
| b = decode64(value); |
| } |
| |
| if (b != null) |
| return b; |
| else |
| return defaultVal; |
| } |
| |
| /** |
| * Helper method for decoding a Base64 string as an byte array. |
| * Returns null on encoding error. This method does not allow any other |
| * characters present in the string then the 65 special base64 chars. |
| */ |
| private static byte[] decode64(String s) { |
| ByteArrayOutputStream bs = new ByteArrayOutputStream((s.length()/4)*3); |
| char[] c = new char[s.length()]; |
| s.getChars(0, s.length(), c, 0); |
| |
| // Convert from base64 chars |
| int endchar = -1; |
| for(int j = 0; j < c.length && endchar == -1; j++) { |
| if (c[j] >= 'A' && c[j] <= 'Z') { |
| c[j] -= 'A'; |
| } else if (c[j] >= 'a' && c[j] <= 'z') { |
| c[j] = (char) (c[j] + 26 - 'a'); |
| } else if (c[j] >= '0' && c[j] <= '9') { |
| c[j] = (char) (c[j] + 52 - '0'); |
| } else if (c[j] == '+') { |
| c[j] = 62; |
| } else if (c[j] == '/') { |
| c[j] = 63; |
| } else if (c[j] == '=') { |
| endchar = j; |
| } else { |
| return null; // encoding exception |
| } |
| } |
| |
| int remaining = endchar == -1 ? c.length : endchar; |
| int i = 0; |
| while (remaining > 0) { |
| // Four input chars (6 bits) are decoded as three bytes as |
| // 000000 001111 111122 222222 |
| |
| byte b0 = (byte) (c[i] << 2); |
| if (remaining >= 2) { |
| b0 += (c[i+1] & 0x30) >> 4; |
| } |
| bs.write(b0); |
| |
| if (remaining >= 3) { |
| byte b1 = (byte) ((c[i+1] & 0x0F) << 4); |
| b1 += (byte) ((c[i+2] & 0x3C) >> 2); |
| bs.write(b1); |
| } |
| |
| if (remaining >= 4) { |
| byte b2 = (byte) ((c[i+2] & 0x03) << 6); |
| b2 += c[i+3]; |
| bs.write(b2); |
| } |
| |
| i += 4; |
| remaining -= 4; |
| } |
| |
| return bs.toByteArray(); |
| } |
| |
| /** |
| * Convenience method for getting the given entry as a double. |
| * When the string representation of the requested entry can be decoded |
| * with <code>Double.parseDouble()</code> then that double is returned, |
| * otherwise the given default double value is returned. |
| * |
| * @exception IllegalArgumentException if key is larger then 80 characters |
| * @exception IllegalStateException if this node has been removed |
| * @exception NullPointerException if key is null |
| */ |
| public double getDouble(String key, double defaultVal) { |
| String value = get(key, null); |
| |
| if (value != null) { |
| try { |
| return Double.parseDouble(value); |
| } catch (NumberFormatException nfe) { /* ignore */ } |
| } |
| |
| return defaultVal; |
| } |
| |
| /** |
| * Convenience method for getting the given entry as a float. |
| * When the string representation of the requested entry can be decoded |
| * with <code>Float.parseFloat()</code> then that float is returned, |
| * otherwise the given default float value is returned. |
| * |
| * @exception IllegalArgumentException if key is larger then 80 characters |
| * @exception IllegalStateException if this node has been removed |
| * @exception NullPointerException if key is null |
| */ |
| public float getFloat(String key, float defaultVal) { |
| String value = get(key, null); |
| |
| if (value != null) { |
| try { |
| return Float.parseFloat(value); |
| } catch (NumberFormatException nfe) { /* ignore */ } |
| } |
| |
| return defaultVal; |
| } |
| |
| /** |
| * Convenience method for getting the given entry as an integer. |
| * When the string representation of the requested entry can be decoded |
| * with <code>Integer.parseInt()</code> then that integer is returned, |
| * otherwise the given default integer value is returned. |
| * |
| * @exception IllegalArgumentException if key is larger then 80 characters |
| * @exception IllegalStateException if this node has been removed |
| * @exception NullPointerException if key is null |
| */ |
| public int getInt(String key, int defaultVal) { |
| String value = get(key, null); |
| |
| if (value != null) { |
| try { |
| return Integer.parseInt(value); |
| } catch (NumberFormatException nfe) { /* ignore */ } |
| } |
| |
| return defaultVal; |
| } |
| |
| /** |
| * Convenience method for getting the given entry as a long. |
| * When the string representation of the requested entry can be decoded |
| * with <code>Long.parseLong()</code> then that long is returned, |
| * otherwise the given default long value is returned. |
| * |
| * @exception IllegalArgumentException if key is larger then 80 characters |
| * @exception IllegalStateException if this node has been removed |
| * @exception NullPointerException if key is null |
| */ |
| public long getLong(String key, long defaultVal) { |
| String value = get(key, null); |
| |
| if (value != null) { |
| try { |
| return Long.parseLong(value); |
| } catch (NumberFormatException nfe) { /* ignore */ } |
| } |
| |
| return defaultVal; |
| } |
| |
| /** |
| * Sets the value of the given preferences entry for this node. |
| * Key and value cannot be null, the key cannot exceed 80 characters |
| * and the value cannot exceed 8192 characters. |
| * <p> |
| * The result will be immediately visible in this VM, but may not be |
| * immediately written to the backing store. |
| * <p> |
| * Checks that key and value are valid, locks this node, and checks that |
| * the node has not been removed. Then it calls <code>putSpi()</code>. |
| * |
| * @exception NullPointerException if either key or value are null |
| * @exception IllegalArgumentException if either key or value are to large |
| * @exception IllegalStateException when this node has been removed |
| */ |
| public void put(String key, String value) { |
| if (key.length() > MAX_KEY_LENGTH |
| || value.length() > MAX_VALUE_LENGTH) |
| throw new IllegalArgumentException("key (" |
| + key.length() + ")" |
| + " or value (" |
| + value.length() + ")" |
| + " to large"); |
| synchronized(lock) { |
| if (isRemoved()) |
| throw new IllegalStateException("Node removed"); |
| |
| putSpi(key, value); |
| |
| if (preferenceListeners != null) |
| fire(new PreferenceChangeEvent(this, key, value)); |
| } |
| |
| } |
| |
| /** |
| * Convenience method for setting the given entry as a boolean. |
| * The boolean is converted with <code>Boolean.toString(value)</code> |
| * and then stored in the preference entry as that string. |
| * |
| * @exception NullPointerException if key is null |
| * @exception IllegalArgumentException if the key length is to large |
| * @exception IllegalStateException when this node has been removed |
| */ |
| public void putBoolean(String key, boolean value) { |
| put(key, Boolean.toString(value)); |
| } |
| |
| /** |
| * Convenience method for setting the given entry as an array of bytes. |
| * The byte array is converted to a Base64 encoded string |
| * and then stored in the preference entry as that string. |
| * <p> |
| * Note that a byte array encoded as a Base64 string will be about 1.3 |
| * times larger then the original length of the byte array, which means |
| * that the byte array may not be larger about 6 KB. |
| * |
| * @exception NullPointerException if either key or value are null |
| * @exception IllegalArgumentException if either key or value are to large |
| * @exception IllegalStateException when this node has been removed |
| */ |
| public void putByteArray(String key, byte[] value) { |
| put(key, encode64(value)); |
| } |
| |
| /** |
| * Helper method for encoding an array of bytes as a Base64 String. |
| */ |
| private static String encode64(byte[] b) { |
| StringBuffer sb = new StringBuffer((b.length/3)*4); |
| |
| int i = 0; |
| int remaining = b.length; |
| char c[] = new char[4]; |
| while (remaining > 0) { |
| // Three input bytes are encoded as four chars (6 bits) as |
| // 00000011 11112222 22333333 |
| |
| c[0] = (char) ((b[i] & 0xFC) >> 2); |
| c[1] = (char) ((b[i] & 0x03) << 4); |
| if (remaining >= 2) { |
| c[1] += (char) ((b[i+1] & 0xF0) >> 4); |
| c[2] = (char) ((b[i+1] & 0x0F) << 2); |
| if (remaining >= 3) { |
| c[2] += (char) ((b[i+2] & 0xC0) >> 6); |
| c[3] = (char) (b[i+2] & 0x3F); |
| } else { |
| c[3] = 64; |
| } |
| } else { |
| c[2] = 64; |
| c[3] = 64; |
| } |
| |
| // Convert to base64 chars |
| for(int j = 0; j < 4; j++) { |
| if (c[j] < 26) { |
| c[j] += 'A'; |
| } else if (c[j] < 52) { |
| c[j] = (char) (c[j] - 26 + 'a'); |
| } else if (c[j] < 62) { |
| c[j] = (char) (c[j] - 52 + '0'); |
| } else if (c[j] == 62) { |
| c[j] = '+'; |
| } else if (c[j] == 63) { |
| c[j] = '/'; |
| } else { |
| c[j] = '='; |
| } |
| } |
| |
| sb.append(c); |
| i += 3; |
| remaining -= 3; |
| } |
| |
| return sb.toString(); |
| } |
| |
| /** |
| * Convenience method for setting the given entry as a double. |
| * The double is converted with <code>Double.toString(double)</code> |
| * and then stored in the preference entry as that string. |
| * |
| * @exception NullPointerException if the key is null |
| * @exception IllegalArgumentException if the key length is to large |
| * @exception IllegalStateException when this node has been removed |
| */ |
| public void putDouble(String key, double value) { |
| put(key, Double.toString(value)); |
| } |
| |
| /** |
| * Convenience method for setting the given entry as a float. |
| * The float is converted with <code>Float.toString(float)</code> |
| * and then stored in the preference entry as that string. |
| * |
| * @exception NullPointerException if the key is null |
| * @exception IllegalArgumentException if the key length is to large |
| * @exception IllegalStateException when this node has been removed |
| */ |
| public void putFloat(String key, float value) { |
| put(key, Float.toString(value)); |
| } |
| |
| /** |
| * Convenience method for setting the given entry as an integer. |
| * The integer is converted with <code>Integer.toString(int)</code> |
| * and then stored in the preference entry as that string. |
| * |
| * @exception NullPointerException if the key is null |
| * @exception IllegalArgumentException if the key length is to large |
| * @exception IllegalStateException when this node has been removed |
| */ |
| public void putInt(String key, int value) { |
| put(key, Integer.toString(value)); |
| } |
| |
| /** |
| * Convenience method for setting the given entry as a long. |
| * The long is converted with <code>Long.toString(long)</code> |
| * and then stored in the preference entry as that string. |
| * |
| * @exception NullPointerException if the key is null |
| * @exception IllegalArgumentException if the key length is to large |
| * @exception IllegalStateException when this node has been removed |
| */ |
| public void putLong(String key, long value) { |
| put(key, Long.toString(value)); |
| } |
| |
| /** |
| * Removes the preferences entry from this preferences node. |
| * <p> |
| * The result will be immediately visible in this VM, but may not be |
| * immediately written to the backing store. |
| * <p> |
| * This implementation checks that the key is not larger then 80 |
| * characters, gets the lock of this node, checks that the node has |
| * not been removed and calls <code>removeSpi</code> with the given key. |
| * |
| * @exception NullPointerException if the key is null |
| * @exception IllegalArgumentException if the key length is to large |
| * @exception IllegalStateException when this node has been removed |
| */ |
| public void remove(String key) { |
| if (key.length() > MAX_KEY_LENGTH) |
| throw new IllegalArgumentException(key); |
| |
| synchronized(lock) { |
| if (isRemoved()) |
| throw new IllegalStateException("Node removed"); |
| |
| removeSpi(key); |
| |
| if (preferenceListeners != null) |
| fire(new PreferenceChangeEvent(this, key, null)); |
| } |
| } |
| |
| /** |
| * Removes all entries from this preferences node. May need access to the |
| * backing store to get and clear all entries. |
| * <p> |
| * The result will be immediately visible in this VM, but may not be |
| * immediatly written to the backing store. |
| * <p> |
| * This implementation locks this node, checks that the node has not been |
| * removed and calls <code>keys()</code> to get a complete array of keys |
| * for this node. For every key found <code>removeSpi()</code> is called. |
| * |
| * @exception BackingStoreException when the backing store cannot be |
| * reached |
| * @exception IllegalStateException if this node has been removed |
| */ |
| public void clear() throws BackingStoreException { |
| synchronized(lock) { |
| if (isRemoved()) |
| throw new IllegalStateException("Node Removed"); |
| |
| String[] keys = keys(); |
| for (int i = 0; i < keys.length; i++) { |
| removeSpi(keys[i]); |
| } |
| } |
| } |
| |
| /** |
| * Writes all preference changes on this and any subnode that have not |
| * yet been written to the backing store. This has no effect on the |
| * preference entries in this VM, but it makes sure that all changes |
| * are visible to other programs (other VMs might need to call the |
| * <code>sync()</code> method to actually see the changes to the backing |
| * store. |
| * <p> |
| * Locks this node, calls the <code>flushSpi()</code> method, gets all |
| * the (cached - already existing in this VM) subnodes and then calls |
| * <code>flushSpi()</code> on every subnode with this node unlocked and |
| * only that particular subnode locked. |
| * |
| * @exception BackingStoreException when the backing store cannot be |
| * reached |
| */ |
| public void flush() throws BackingStoreException { |
| flushNode(false); |
| } |
| |
| /** |
| * Writes and reads all preference changes to and from this and any |
| * subnodes. This makes sure that all local changes are written to the |
| * backing store and that all changes to the backing store are visible |
| * in this preference node (and all subnodes). |
| * <p> |
| * Checks that this node is not removed, locks this node, calls the |
| * <code>syncSpi()</code> method, gets all the subnodes and then calls |
| * <code>syncSpi()</code> on every subnode with this node unlocked and |
| * only that particular subnode locked. |
| * |
| * @exception BackingStoreException when the backing store cannot be |
| * reached |
| * @exception IllegalStateException if this node has been removed |
| */ |
| public void sync() throws BackingStoreException { |
| flushNode(true); |
| } |
| |
| |
| /** |
| * Private helper method that locks this node and calls either |
| * <code>flushSpi()</code> if <code>sync</code> is false, or |
| * <code>flushSpi()</code> if <code>sync</code> is true. Then it gets all |
| * the currently cached subnodes. For every subnode it calls this method |
| * recursively with this node no longer locked. |
| * <p> |
| * Called by either <code>flush()</code> or <code>sync()</code> |
| */ |
| private void flushNode(boolean sync) throws BackingStoreException { |
| String[] keys = null; |
| synchronized(lock) { |
| if (sync) { |
| syncSpi(); |
| } else { |
| flushSpi(); |
| } |
| keys = (String[]) childCache.keySet().toArray(new String[]{}); |
| } |
| |
| if (keys != null) { |
| for (int i = 0; i < keys.length; i++) { |
| // Have to lock this node again to access the childCache |
| AbstractPreferences subNode; |
| synchronized(lock) { |
| subNode = (AbstractPreferences) childCache.get(keys[i]); |
| } |
| |
| // The child could already have been removed from the cache |
| if (subNode != null) { |
| subNode.flushNode(sync); |
| } |
| } |
| } |
| } |
| |
| /** |
| * Removes this and all subnodes from the backing store and clears all |
| * entries. After removal this instance will not be useable (except for |
| * a few methods that don't throw a <code>InvalidStateException</code>), |
| * even when a new node with the same path name is created this instance |
| * will not be usable again. |
| * <p> |
| * Checks that this is not a root node. If not it locks the parent node, |
| * then locks this node and checks that the node has not yet been removed. |
| * Then it makes sure that all subnodes of this node are in the child cache, |
| * by calling <code>childSpi()</code> on any children not yet in the cache. |
| * Then for all children it locks the subnode and removes it. After all |
| * subnodes have been purged the child cache is cleared, this nodes removed |
| * flag is set and any listeners are called. Finally this node is removed |
| * from the child cache of the parent node. |
| * |
| * @exception BackingStoreException when the backing store cannot be |
| * reached |
| * @exception IllegalStateException if this node has already been removed |
| * @exception UnsupportedOperationException if this is a root node |
| */ |
| public void removeNode() throws BackingStoreException { |
| // Check if it is a root node |
| if (parent == null) |
| throw new UnsupportedOperationException("Cannot remove root node"); |
| |
| synchronized (parent.lock) { |
| synchronized(this.lock) { |
| if (isRemoved()) |
| throw new IllegalStateException("Node Removed"); |
| |
| purge(); |
| } |
| parent.childCache.remove(name); |
| } |
| } |
| |
| /** |
| * Private helper method used to completely remove this node. |
| * Called by <code>removeNode</code> with the parent node and this node |
| * locked. |
| * <p> |
| * Makes sure that all subnodes of this node are in the child cache, |
| * by calling <code>childSpi()</code> on any children not yet in the |
| * cache. Then for all children it locks the subnode and calls this method |
| * on that node. After all subnodes have been purged the child cache is |
| * cleared, this nodes removed flag is set and any listeners are called. |
| */ |
| private void purge() throws BackingStoreException |
| { |
| // Make sure all children have an AbstractPreferences node in cache |
| String children[] = childrenNamesSpi(); |
| for (int i = 0; i < children.length; i++) { |
| if (childCache.get(children[i]) == null) |
| childCache.put(children[i], childSpi(children[i])); |
| } |
| |
| // purge all children |
| Iterator i = childCache.values().iterator(); |
| while (i.hasNext()) { |
| AbstractPreferences node = (AbstractPreferences) i.next(); |
| synchronized(node.lock) { |
| node.purge(); |
| } |
| } |
| |
| // Cache is empty now |
| childCache.clear(); |
| |
| // remove this node |
| removeNodeSpi(); |
| removed = true; |
| |
| if (nodeListeners != null) |
| fire(new NodeChangeEvent(parent, this), false); |
| } |
| |
| // listener methods |
| |
| /** |
| * Add a listener which is notified when a sub-node of this node |
| * is added or removed. |
| * @param listener the listener to add |
| */ |
| public void addNodeChangeListener(NodeChangeListener listener) |
| { |
| synchronized (lock) |
| { |
| if (isRemoved()) |
| throw new IllegalStateException("node has been removed"); |
| if (listener == null) |
| throw new NullPointerException("listener is null"); |
| if (nodeListeners == null) |
| nodeListeners = new ArrayList(); |
| nodeListeners.add(listener); |
| } |
| } |
| |
| /** |
| * Add a listener which is notified when a value in this node |
| * is added, changed, or removed. |
| * @param listener the listener to add |
| */ |
| public void addPreferenceChangeListener(PreferenceChangeListener listener) |
| { |
| synchronized (lock) |
| { |
| if (isRemoved()) |
| throw new IllegalStateException("node has been removed"); |
| if (listener == null) |
| throw new NullPointerException("listener is null"); |
| if (preferenceListeners == null) |
| preferenceListeners = new ArrayList(); |
| preferenceListeners.add(listener); |
| } |
| } |
| |
| /** |
| * Remove the indicated node change listener from the list of |
| * listeners to notify. |
| * @param listener the listener to remove |
| */ |
| public void removeNodeChangeListener(NodeChangeListener listener) |
| { |
| synchronized (lock) |
| { |
| if (isRemoved()) |
| throw new IllegalStateException("node has been removed"); |
| if (listener == null) |
| throw new NullPointerException("listener is null"); |
| if (nodeListeners != null) |
| nodeListeners.remove(listener); |
| } |
| } |
| |
| /** |
| * Remove the indicated preference change listener from the list of |
| * listeners to notify. |
| * @param listener the listener to remove |
| */ |
| public void removePreferenceChangeListener (PreferenceChangeListener listener) |
| { |
| synchronized (lock) |
| { |
| if (isRemoved()) |
| throw new IllegalStateException("node has been removed"); |
| if (listener == null) |
| throw new NullPointerException("listener is null"); |
| if (preferenceListeners != null) |
| preferenceListeners.remove(listener); |
| } |
| } |
| |
| /** |
| * Send a preference change event to all listeners. Note that |
| * the caller is responsible for holding the node's lock, and |
| * for checking that the list of listeners is not null. |
| * @param event the event to send |
| */ |
| private void fire(final PreferenceChangeEvent event) |
| { |
| Iterator it = preferenceListeners.iterator(); |
| while (it.hasNext()) |
| { |
| final PreferenceChangeListener l = (PreferenceChangeListener) it.next(); |
| EventDispatcher.dispatch(new Runnable() |
| { |
| public void run() |
| { |
| l.preferenceChange(event); |
| } |
| }); |
| } |
| } |
| |
| /** |
| * Send a node change event to all listeners. Note that |
| * the caller is responsible for holding the node's lock, and |
| * for checking that the list of listeners is not null. |
| * @param event the event to send |
| */ |
| private void fire(final NodeChangeEvent event, final boolean added) |
| { |
| Iterator it = nodeListeners.iterator(); |
| while (it.hasNext()) |
| { |
| final NodeChangeListener l = (NodeChangeListener) it.next(); |
| EventDispatcher.dispatch(new Runnable() |
| { |
| public void run() |
| { |
| if (added) |
| l.childAdded(event); |
| else |
| l.childRemoved(event); |
| } |
| }); |
| } |
| } |
| |
| // abstract spi methods |
| |
| /** |
| * Returns the names of the sub nodes of this preference node. |
| * This method only has to return any not yet cached child names, |
| * but may return all names if that is easier. It must not return |
| * null when there are no children, it has to return an empty array |
| * in that case. Since this method must consult the backing store to |
| * get all the sub node names it may throw a BackingStoreException. |
| * <p> |
| * Called by <code>childrenNames()</code> with this node locked. |
| */ |
| protected abstract String[] childrenNamesSpi() throws BackingStoreException; |
| |
| /** |
| * Returns a child note with the given name. |
| * This method is called by the <code>node()</code> method (indirectly |
| * through the <code>getNode()</code> helper method) with this node locked |
| * if a sub node with this name does not already exist in the child cache. |
| * If the child node did not aleady exist in the backing store the boolean |
| * field <code>newNode</code> of the returned node should be set. |
| * <p> |
| * Note that this method should even return a non-null child node if the |
| * backing store is not available since it may not throw a |
| * <code>BackingStoreException</code>. |
| */ |
| protected abstract AbstractPreferences childSpi(String name); |
| |
| /** |
| * Returns an (possibly empty) array with all the keys of the preference |
| * entries of this node. |
| * <p> |
| * Called by <code>keys()</code> with this node locked if this node has |
| * not been removed. May throw an exception when the backing store cannot |
| * be accessed. |
| * |
| * @exception BackingStoreException when the backing store cannot be |
| * reached |
| */ |
| protected abstract String[] keysSpi() throws BackingStoreException; |
| |
| /** |
| * Returns the value associated with the key in this preferences node or |
| * null when the key does not exist in this preferences node. |
| * <p> |
| * Called by <code>key()</code> with this node locked after checking that |
| * key is valid, not null and that the node has not been removed. |
| * <code>key()</code> will catch any exceptions that this method throws. |
| */ |
| protected abstract String getSpi(String key); |
| |
| /** |
| * Sets the value of the given preferences entry for this node. |
| * The implementation is not required to propagate the change to the |
| * backing store immediately. It may not throw an exception when it tries |
| * to write to the backing store and that operation fails, the failure |
| * should be registered so a later invocation of <code>flush()</code> |
| * or <code>sync()</code> can signal the failure. |
| * <p> |
| * Called by <code>put()</code> with this node locked after checking that |
| * key and value are valid and non-null. |
| */ |
| protected abstract void putSpi(String key, String value); |
| |
| /** |
| * Removes the given key entry from this preferences node. |
| * The implementation is not required to propagate the change to the |
| * backing store immediately. It may not throw an exception when it tries |
| * to write to the backing store and that operation fails, the failure |
| * should be registered so a later invocation of <code>flush()</code> |
| * or <code>sync()</code> can signal the failure. |
| * <p> |
| * Called by <code>remove()</code> with this node locked after checking |
| * that the key is valid and non-null. |
| */ |
| protected abstract void removeSpi(String key); |
| |
| /** |
| * Writes all entries of this preferences node that have not yet been |
| * written to the backing store and possibly creates this node in the |
| * backing store, if it does not yet exist. Should only write changes to |
| * this node and not write changes to any subnodes. |
| * Note that the node can be already removed in this VM. To check if |
| * that is the case the implementation can call <code>isRemoved()</code>. |
| * <p> |
| * Called (indirectly) by <code>flush()</code> with this node locked. |
| */ |
| protected abstract void flushSpi() throws BackingStoreException; |
| |
| /** |
| * Writes all entries of this preferences node that have not yet been |
| * written to the backing store and reads any entries that have changed |
| * in the backing store but that are not yet visible in this VM. |
| * Should only sync this node and not change any of the subnodes. |
| * Note that the node can be already removed in this VM. To check if |
| * that is the case the implementation can call <code>isRemoved()</code>. |
| * <p> |
| * Called (indirectly) by <code>sync()</code> with this node locked. |
| */ |
| protected abstract void syncSpi() throws BackingStoreException; |
| |
| /** |
| * Clears this node from this VM and removes it from the backing store. |
| * After this method has been called the node is marked as removed. |
| * <p> |
| * Called (indirectly) by <code>removeNode()</code> with this node locked |
| * after all the sub nodes of this node have already been removed. |
| */ |
| protected abstract void removeNodeSpi() throws BackingStoreException; |
| } |
