org.mdiutil.prefs

Class MemoryPreferences

java.lang.Object

java.util.prefs.Preferences

java.util.prefs.AbstractPreferences

org.mdiutil.prefs.MemoryPreferences

public class MemoryPreferences
extends AbstractPreferences

This class provides an in memory implementation of the java.util.prefs.Preferences class.

Since:

0.4

Field Summary

Fields

Modifier and Type	Field and Description
protected MemoryPreferences	myparent
protected Map<String,Preferences>	nodes
static int	SYSTEM_NODE
static int	USER_NODE

Fields inherited from class java.util.prefs.AbstractPreferences

lock, newNode

Fields inherited from class java.util.prefs.Preferences

MAX_KEY_LENGTH, MAX_NAME_LENGTH, MAX_VALUE_LENGTH

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	MemoryPreferences(MemoryPreferences parent, String name) Creates a preference node with the specified parent and the specified name relative to its parent.
protected	MemoryPreferences(String name) create a new user Node NetworkPreferences.

Method Summary

Modifier and Type	Method and Description
protected String[]	childrenNamesSpi() Returns the names of the children of this preference node.
protected AbstractPreferences	childSpi(String name) Returns the named child of this preference node, creating it if it does not already exist.
void	exportNode(OutputStream os) Implements the exportNode method as per the specification in Preferences.exportNode(OutputStream).
void	exportSubtree(OutputStream os) Implements the exportSubtree method as per the specification in Preferences.exportSubtree(OutputStream).
void	flush()
protected void	flushSpi() Empty, never used implementation of AbstractPreferences.flushSpi().
Object	getLock()
protected Map	getMapImpl() return the backstore Hashtable implementation for the (key, value) map.
protected Map	getNodeImpl() return the backstore Hashtable implementation for the nodes.
protected String	getSpi(String key) Return the value associated with the specified key at this preference node, or null if there is no association for this key, or the association cannot be determined at this time.
static void	importPreferences(InputStream is) Imports all of the preferences represented by the XML document on the specified input stream.
boolean	isInRemoveLock()
boolean	isUserNode()
protected String[]	keysSpi() Returns all of the keys that have an associated value in this preference node.
Preferences	node(String name)
void	put(String key, String value)
protected void	putSpi(String key, String value) Put the given key-value association into this preference node.
protected void	removeNodeSpi() Removes this preference node, invalidating it and any preferences that it contains.
protected void	removeSpi(String key) Remove the association (if any) for the specified key at this preference node.
void	sync() Identical to flush().
protected void	syncSpi() Empty, never used implementation of AbstractPreferences.syncSpi().
static Preferences	systemNodeForPackage(Class c)
static Preferences	userNodeForPackage(Class c)

Methods inherited from class java.util.prefs.AbstractPreferences

absolutePath, addNodeChangeListener, addPreferenceChangeListener, cachedChildren, childrenNames, clear, get, getBoolean, getByteArray, getChild, getDouble, getFloat, getInt, getLong, isRemoved, keys, name, nodeExists, parent, putBoolean, putByteArray, putDouble, putFloat, putInt, putLong, remove, removeNode, removeNodeChangeListener, removePreferenceChangeListener, toString

Methods inherited from class java.util.prefs.Preferences

systemNodeForPackage, systemRoot, userNodeForPackage, userRoot

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

USER_NODE

public static final int USER_NODE

See Also:

Constant Field Values

SYSTEM_NODE

public static final int SYSTEM_NODE

See Also:

Constant Field Values

myparent

protected MemoryPreferences myparent

nodes

protected Map<String,Preferences> nodes

Constructor Detail

MemoryPreferences

protected MemoryPreferences(String name)

create a new user Node NetworkPreferences.

MemoryPreferences

protected MemoryPreferences(MemoryPreferences parent,
                            String name)

Creates a preference node with the specified parent and the specified name relative to its parent.

Parameters:

parent - the parent of this preference node, or null if this is the root.

name - the name of this preference node, relative to its parent, or "" if this is the root.

Throws:

IllegalArgumentException - if name contains a slash ('/'), or parent is null and name isn't "".

Method Detail

putSpi

protected void putSpi(String key,
                      String value)

Put the given key-value association into this preference node.

Specified by:

putSpi in class AbstractPreferences

put

public void put(String key,
                String value)

Overrides:

put in class AbstractPreferences

getSpi

protected String getSpi(String key)

Return the value associated with the specified key at this preference node, or null if there is no association for this key, or the association cannot be determined at this time.

Specified by:

getSpi in class AbstractPreferences

Returns:

the value associated with the specified key at this preference node, or null if there is no association for this key, or the association cannot be determined at this time.

removeSpi

protected void removeSpi(String key)

Remove the association (if any) for the specified key at this preference node.

Specified by:

removeSpi in class AbstractPreferences

removeNodeSpi

protected void removeNodeSpi()
                      throws BackingStoreException

Removes this preference node, invalidating it and any preferences that it contains. The named child will have no descendants at the time this invocation is made (i.e., the Preferences.removeNode() method invokes this method repeatedly in a bottom-up fashion, removing each of a node's descendants before removing the node itself).

The removal of a node will not become persistent until the flush method is invoked on this node (or an ancestor).

Specified by:

removeNodeSpi in class AbstractPreferences

Throws:

BackingStoreException - if this operation cannot be completed due to a failure in the backing store, or inability to communicate with it.

keysSpi

protected String[] keysSpi()
                    throws BackingStoreException

Returns all of the keys that have an associated value in this preference node. (The returned array will be of size zero if this node has no preferences).

If this node throws a BackingStoreException, the exception will propagate out beyond the enclosing AbstractPreferences.keys() invocation.

Specified by:

keysSpi in class AbstractPreferences

Returns:

an array of the keys that have an associated value in this preference node.

Throws:

BackingStoreException - if this operation cannot be completed due to a failure in the backing store, or inability to communicate with it.

childrenNamesSpi

protected String[] childrenNamesSpi()
                             throws BackingStoreException

Returns the names of the children of this preference node. (The returned array will be of size zero if this node has no children.)

If this node throws a BackingStoreException, the exception will propagate out beyond the enclosing AbstractPreferences.childrenNames() invocation.

Specified by:

childrenNamesSpi in class AbstractPreferences

Returns:

an array containing the names of the children of this preference node.

Throws:

BackingStoreException - if this operation cannot be completed due to a failure in the backing store, or inability to communicate with it.

childSpi

protected AbstractPreferences childSpi(String name)

Returns the named child of this preference node, creating it if it does not already exist.

Specified by:

childSpi in class AbstractPreferences

Parameters:

name - The name of the child node to return, relative to this preference node.

Returns:

The named child node.

syncSpi

protected void syncSpi()
                throws BackingStoreException

Empty, never used implementation of AbstractPreferences.syncSpi().

Specified by:

syncSpi in class AbstractPreferences

Throws:

BackingStoreException

sync

public void sync()
          throws BackingStoreException

Identical to flush().

Overrides:

sync in class AbstractPreferences

Throws:

BackingStoreException

flushSpi

protected void flushSpi()
                 throws BackingStoreException

Empty, never used implementation of AbstractPreferences.flushSpi().

Specified by:

flushSpi in class AbstractPreferences

Throws:

BackingStoreException

flush

public void flush()
           throws BackingStoreException

Overrides:

flush in class AbstractPreferences

Throws:

BackingStoreException

isUserNode

public boolean isUserNode()

Overrides:

isUserNode in class AbstractPreferences

Returns:

true if this Preference is in the user preference tree.

getLock

public Object getLock()

isInRemoveLock

public boolean isInRemoveLock()

exportNode

public void exportNode(OutputStream os)
                throws IOException,
                       BackingStoreException

Implements the exportNode method as per the specification in Preferences.exportNode(OutputStream).

Overrides:

exportNode in class AbstractPreferences

Parameters:

os - the output stream on which to emit the XML document.

Throws:

IOException - if writing to the specified output stream results in an IOException.

BackingStoreException - if preference data cannot be read from backing store.

exportSubtree

public void exportSubtree(OutputStream os)
                   throws IOException,
                          BackingStoreException

Implements the exportSubtree method as per the specification in Preferences.exportSubtree(OutputStream).

Overrides:

exportSubtree in class AbstractPreferences

Parameters:

os - the output stream on which to emit the XML document.

Throws:

IOException - if writing to the specified output stream results in an IOException.

BackingStoreException - if preference data cannot be read from backing store.

importPreferences

public static void importPreferences(InputStream is)
                              throws IOException,
                                     InvalidPreferencesFormatException

Imports all of the preferences represented by the XML document on the specified input stream. The document may represent user preferences or system preferences. If it represents user preferences, the preferences will be imported into the calling user's preference tree (even if they originally came from a different user's preference tree). If any of the preferences described by the document inhabit preference nodes that do not exist, the nodes will be created.

Parameters:

is - the input stream from which to read the XML document.

Throws:

IOException - if reading from the specified output stream results in an IOException.

InvalidPreferencesFormatException - Data on input stream does not constitute a valid XML document with the mandated document type.

userNodeForPackage

public static Preferences userNodeForPackage(Class c)

systemNodeForPackage

public static Preferences systemNodeForPackage(Class c)

getNodeImpl

protected Map getNodeImpl()

return the backstore Hashtable implementation for the nodes. this is not used by this implementation, but can be used by subclasses.

getMapImpl

protected Map getMapImpl()

return the backstore Hashtable implementation for the (key, value) map. this is not used by this implementation, but can be used by subclasses.

node

public Preferences node(String name)

Overrides:

node in class AbstractPreferences