org.apache.felix.prefs

Class PreferencesImpl

java.lang.Object

org.apache.felix.prefs.PreferencesImpl

All Implemented Interfaces:

org.osgi.service.prefs.Preferences

public class PreferencesImpl
extends Object
implements org.osgi.service.prefs.Preferences

This is an implementation of the preferences. The access to the preferences is synchronized on the instance by making (nearly) all public methods synchronized. This avoids the heavy management of a separate read/write lock. Such a lock is too heavy for the simple operations preferences support. The various getXX and putXX methods are not synchronized as they all use the get/put methods which are synchronized.

Field Summary

Fields

Modifier and Type	Field and Description
protected ChangeSet	changeSet The change set keeps track of all changes.
protected Map<String,PreferencesImpl>	children The child nodes.
protected PreferencesDescription	description The description for this preferences.
protected String	name The name of the properties.
protected PreferencesImpl	parent The parent.
protected Map<String,String>	properties The properties.
protected BackingStoreManager	storeManager The backing store manager.
protected boolean	valid Has this node been removed?

Constructor Summary

Constructors

Constructor and Description
PreferencesImpl(PreferencesDescription d, BackingStoreManager storeManager) Construct the root node of the tree.
PreferencesImpl(PreferencesImpl p, String name) Construct a child node.

Method Summary

Methods

Modifier and Type	Method and Description
String	absolutePath()
void	applyChanges(PreferencesImpl prefs) Apply the changes done to the passed preferences object.
protected void	checkKey(String key) The key is not allowed to be null.
protected void	checkValidity() Check if this node is still valid.
protected void	checkValue(Object value) The value is not allowed to be null.
String[]	childrenNames()
void	clear()
void	flush()
String	get(String key, String def)
BackingStoreManager	getBackingStoreManager() Return the backing store manager.
boolean	getBoolean(String key, boolean def)
byte[]	getByteArray(String key, byte[] def)
ChangeSet	getChangeSet() Return the change set.
Collection<PreferencesImpl>	getChildren() Return all children or an empty collection.
PreferencesDescription	getDescription() Return the preferences description.
double	getDouble(String key, double def)
float	getFloat(String key, float def)
int	getInt(String key, int def)
long	getLong(String key, long def)
protected PreferencesImpl	getNode(String path, boolean saveNewlyCreatedNode, boolean create) Get a relative node.
PreferencesImpl	getOrCreateNode(String pathName) Get or create the node.
Map<String,String>	getProperties() Return the properties set.
PreferencesImpl	getRoot() Get the root preferences.
boolean	isValid()
String[]	keys()
String	name()
org.osgi.service.prefs.Preferences	node(String pathName) We do not synchronize this method to avoid dead locks as this method might call another preferences object in the hierarchy.
boolean	nodeExists(String pathName) We do not synchronize this method to avoid dead locks as this method might call another preferences object in the hierarchy.
org.osgi.service.prefs.Preferences	parent()
void	put(String key, String value)
void	putBoolean(String key, boolean value)
void	putByteArray(String key, byte[] value)
void	putDouble(String key, double value)
void	putFloat(String key, float value)
void	putInt(String key, int value)
void	putLong(String key, long value)
void	remove(String key)
protected void	removeChild(PreferencesImpl child)
void	removeNode()
protected void	safelyRemoveNode() Safely remove a node by resetting all properties and calling this method on all children recursively.
void	sync()
void	update(PreferencesImpl impl) Update from the preferences impl.

Methods inherited from class java.lang.Object

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

Field Detail

properties

protected final Map<String,String> properties

The properties.

valid

protected boolean valid

Has this node been removed?

parent

protected final PreferencesImpl parent

The parent.

children

protected final Map<String,PreferencesImpl> children

The child nodes.

name

protected final String name

The name of the properties.

description

protected final PreferencesDescription description

The description for this preferences.

storeManager

protected final BackingStoreManager storeManager

The backing store manager.

changeSet

protected final ChangeSet changeSet

The change set keeps track of all changes.

Constructor Detail

PreferencesImpl

public PreferencesImpl(PreferencesDescription d,
               BackingStoreManager storeManager)

Construct the root node of the tree.

Parameters:

d - The unique description.

storeManager - The backing store.

PreferencesImpl

public PreferencesImpl(PreferencesImpl p,
               String name)

Construct a child node.

Parameters:

p - The parent node.

name - The node name

Method Detail

getChangeSet

public ChangeSet getChangeSet()

Return the change set.

getDescription

public PreferencesDescription getDescription()

Return the preferences description.

Returns:

The preferences description.

getRoot

public PreferencesImpl getRoot()

Get the root preferences.

getChildren

public Collection<PreferencesImpl> getChildren()

Return all children or an empty collection.

Returns:

A collection containing the children.

getProperties

public Map<String,String> getProperties()

Return the properties set.

getBackingStoreManager

public BackingStoreManager getBackingStoreManager()

Return the backing store manager.

checkValidity

protected void checkValidity()
                      throws IllegalStateException

Check if this node is still valid. It gets invalid if it has been removed.

Throws:

IllegalStateException

checkKey

protected void checkKey(String key)
                 throws NullPointerException

The key is not allowed to be null.

Throws:

NullPointerException

checkValue

protected void checkValue(Object value)
                   throws NullPointerException

The value is not allowed to be null.

Throws:

NullPointerException

isValid

public boolean isValid()

put

public void put(String key,
       String value)

Specified by:

put in interface org.osgi.service.prefs.Preferences

See Also:

Preferences.put(java.lang.String, java.lang.String)

get

public String get(String key,
         String def)

Specified by:

get in interface org.osgi.service.prefs.Preferences

See Also:

Preferences.get(java.lang.String, java.lang.String)

remove

public void remove(String key)

Specified by:

remove in interface org.osgi.service.prefs.Preferences

See Also:

Preferences.remove(java.lang.String)

clear

public void clear()
           throws org.osgi.service.prefs.BackingStoreException

Specified by:

clear in interface org.osgi.service.prefs.Preferences

Throws:

org.osgi.service.prefs.BackingStoreException

See Also:

Preferences.clear()

putInt

public void putInt(String key,
          int value)

Specified by:

putInt in interface org.osgi.service.prefs.Preferences

See Also:

Preferences.putInt(java.lang.String, int)

getInt

public int getInt(String key,
         int def)

Specified by:

getInt in interface org.osgi.service.prefs.Preferences

See Also:

Preferences.getInt(java.lang.String, int)

putLong

public void putLong(String key,
           long value)

Specified by:

putLong in interface org.osgi.service.prefs.Preferences

See Also:

Preferences.putLong(java.lang.String, long)

getLong

public long getLong(String key,
           long def)

Specified by:

getLong in interface org.osgi.service.prefs.Preferences

See Also:

Preferences.getLong(java.lang.String, long)

putBoolean

public void putBoolean(String key,
              boolean value)

Specified by:

putBoolean in interface org.osgi.service.prefs.Preferences

See Also:

Preferences.putBoolean(java.lang.String, boolean)

getBoolean

public boolean getBoolean(String key,
                 boolean def)

Specified by:

getBoolean in interface org.osgi.service.prefs.Preferences

See Also:

Preferences.getBoolean(java.lang.String, boolean)

putFloat

public void putFloat(String key,
            float value)

Specified by:

putFloat in interface org.osgi.service.prefs.Preferences

See Also:

Preferences.putFloat(java.lang.String, float)

getFloat

public float getFloat(String key,
             float def)

Specified by:

getFloat in interface org.osgi.service.prefs.Preferences

See Also:

Preferences.getFloat(java.lang.String, float)

putDouble

public void putDouble(String key,
             double value)

Specified by:

putDouble in interface org.osgi.service.prefs.Preferences

See Also:

Preferences.putDouble(java.lang.String, double)

getDouble

public double getDouble(String key,
               double def)

Specified by:

getDouble in interface org.osgi.service.prefs.Preferences

See Also:

Preferences.getDouble(java.lang.String, double)

putByteArray

public void putByteArray(String key,
                byte[] value)

Specified by:

putByteArray in interface org.osgi.service.prefs.Preferences

See Also:

Preferences.putByteArray(java.lang.String, byte[])

getByteArray

public byte[] getByteArray(String key,
                  byte[] def)

Specified by:

getByteArray in interface org.osgi.service.prefs.Preferences

See Also:

Preferences.getByteArray(java.lang.String, byte[])

keys

public String[] keys()
              throws org.osgi.service.prefs.BackingStoreException

Specified by:

keys in interface org.osgi.service.prefs.Preferences

Throws:

org.osgi.service.prefs.BackingStoreException

See Also:

Preferences.keys()

childrenNames

public String[] childrenNames()
                       throws org.osgi.service.prefs.BackingStoreException

Specified by:

childrenNames in interface org.osgi.service.prefs.Preferences

Throws:

org.osgi.service.prefs.BackingStoreException

See Also:

Preferences.childrenNames()

parent

public org.osgi.service.prefs.Preferences parent()

Specified by:

parent in interface org.osgi.service.prefs.Preferences

See Also:

Preferences.parent()

node

public org.osgi.service.prefs.Preferences node(String pathName)

We do not synchronize this method to avoid dead locks as this method might call another preferences object in the hierarchy.

Specified by:

node in interface org.osgi.service.prefs.Preferences

See Also:

Preferences.node(java.lang.String)

getOrCreateNode

public PreferencesImpl getOrCreateNode(String pathName)

Get or create the node. If the node already exists, it's just returned. If not it is created.

Parameters:

pathName -

Returns:

The preferences impl for the path.

getNode

protected PreferencesImpl getNode(String path,
                      boolean saveNewlyCreatedNode,
                      boolean create)

Get a relative node.

Parameters:

path -

Returns:

nodeExists

public boolean nodeExists(String pathName)
                   throws org.osgi.service.prefs.BackingStoreException

We do not synchronize this method to avoid dead locks as this method might call another preferences object in the hierarchy.

Specified by:

nodeExists in interface org.osgi.service.prefs.Preferences

Throws:

org.osgi.service.prefs.BackingStoreException

See Also:

Preferences.nodeExists(java.lang.String)

removeNode

public void removeNode()
                throws org.osgi.service.prefs.BackingStoreException

Specified by:

removeNode in interface org.osgi.service.prefs.Preferences

Throws:

org.osgi.service.prefs.BackingStoreException

See Also:

Preferences.removeNode()

safelyRemoveNode

protected void safelyRemoveNode()

Safely remove a node by resetting all properties and calling this method on all children recursively.

removeChild

protected void removeChild(PreferencesImpl child)

name

public String name()

Specified by:

name in interface org.osgi.service.prefs.Preferences

See Also:

Preferences.name()

absolutePath

public String absolutePath()

Specified by:

absolutePath in interface org.osgi.service.prefs.Preferences

See Also:

Preferences.absolutePath()

flush

public void flush()
           throws org.osgi.service.prefs.BackingStoreException

Specified by:

flush in interface org.osgi.service.prefs.Preferences

Throws:

org.osgi.service.prefs.BackingStoreException

See Also:

Preferences.flush()

sync

public void sync()
          throws org.osgi.service.prefs.BackingStoreException

Specified by:

sync in interface org.osgi.service.prefs.Preferences

Throws:

org.osgi.service.prefs.BackingStoreException

See Also:

Preferences.sync()

update

public void update(PreferencesImpl impl)

Update from the preferences impl.

Parameters:

impl -

applyChanges

public void applyChanges(PreferencesImpl prefs)

Apply the changes done to the passed preferences object.

Parameters:

prefs -