org.xnap.commons.settings
Class PropertyResource

java.lang.Object
  org.xnap.commons.settings.PropertyResource

All Implemented Interfaces:

SettingResource

public class PropertyResource
extends Object
implements SettingResource

This class provides a default implementation for a preferences framework. Methods are provided that can read and write native types, arrays and a few custom types.

Field Summary

protected boolean	changedFlag Determines if preferences need to be saved.
protected static org.apache.commons.logging.Log	logger
protected String	namespace The namespace is prefixed to each key.
protected int	oldVersion Version of database when read.
protected Properties	properties Preferences.
protected PropertyChangeSupport	propertyChange
protected int	version Version of database format.

Constructor Summary

PropertyResource()

PropertyResource(int version, String namespace)
Constructs a PreferencesSupport object.

Method Summary

void	addPropertyChangeListener(PropertyChangeListener l) Adds a preferences listener.
void	addPropertyChangeListener(String key, PropertyChangeListener l) Adds a preferences listener for a specific key.
protected void	convert(int oldVersion) Invoked by load(File) to converts preferences from oldVersion to current version.
boolean	equals(Object o) Returns true if o is the same object or if its version number, namespace and properties map are equal to this' fields.
void	firePropertyChange(String key, Object oldValue, Object newValue) Fires PropertyChangeEvent without namespace.
String	get(String key, String defaultValue) Returns the value to which the specified key is mapped.
int	getOldVersion() Returns the version of the preferences in the file at the point of the last read operation.
int	getVersion() Returns the current version of the preferences.
void	load(File prefsFile) Reads preferences from prefsFile.
void	put(String key, String newValue)
void	remove(String key) Ignores namespace.
void	removePropertyChangeListener(PropertyChangeListener l) Removes a preferences listener.
void	removePropertyChangeListener(String key, PropertyChangeListener l)
void	renameProperty(String oldKey, String newKey) Renames a property, used for conversion of property file formats.
boolean	store(File prefsFile) Writes preferences to default preferences file.

Methods inherited from class java.lang.Object

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

Field Detail

logger

protected static org.apache.commons.logging.Log logger

propertyChange

protected transient PropertyChangeSupport propertyChange

changedFlag

protected boolean changedFlag

Determines if preferences need to be saved.

version

protected int version

Version of database format.

oldVersion

protected int oldVersion

Version of database when read.

namespace

protected String namespace

The namespace is prefixed to each key.

properties

protected Properties properties

Preferences.

Constructor Detail

PropertyResource

public PropertyResource(int version,
                        String namespace)

Constructs a PreferencesSupport object.

Parameters:

version - the current version of the preferences, this version can be more recent than the version of the file

namespace - the namespace, used as a prefix for all keys

PropertyResource

public PropertyResource()

Method Detail

load

public void load(File prefsFile)
          throws IOException

Reads preferences from prefsFile.

Throws:

IOException

store

public boolean store(File prefsFile)
              throws IOException

Writes preferences to default preferences file. If preferences have not changed since the last read or write operation, no action is taken.

Returns:

true, if file is written successfully or preferences were not changed; false, if an IOException has occured

Throws:

IOException

equals

public boolean equals(Object o)

Returns true if o is the same object or if its version number, namespace and properties map are equal to this' fields.

Overrides:

equals in class Object

getOldVersion

public int getOldVersion()

Returns the version of the preferences in the file at the point of the last read operation.

getVersion

public int getVersion()

Returns the current version of the preferences.

convert

protected void convert(int oldVersion)

Invoked by load(File) to converts preferences from oldVersion to current version.

addPropertyChangeListener

public void addPropertyChangeListener(PropertyChangeListener l)

Adds a preferences listener.

addPropertyChangeListener

public void addPropertyChangeListener(String key,
                                      PropertyChangeListener l)

Adds a preferences listener for a specific key.

Specified by:

addPropertyChangeListener in interface SettingResource

firePropertyChange

public void firePropertyChange(String key,
                               Object oldValue,
                               Object newValue)

Fires PropertyChangeEvent without namespace.

Specified by:

firePropertyChange in interface SettingResource

removePropertyChangeListener

public void removePropertyChangeListener(PropertyChangeListener l)

Removes a preferences listener.

removePropertyChangeListener

public void removePropertyChangeListener(String key,
                                         PropertyChangeListener l)

Specified by:

removePropertyChangeListener in interface SettingResource

get

public String get(String key,
                  String defaultValue)

Description copied from interface: SettingResource

Returns the value to which the specified key is mapped.

Specified by:

get in interface SettingResource

put

public void put(String key,
                String newValue)

Specified by:

put in interface SettingResource

remove

public void remove(String key)

Ignores namespace.

Specified by:

remove in interface SettingResource

renameProperty

public void renameProperty(String oldKey,
                           String newKey)

Renames a property, used for conversion of property file formats. Ignores namespace. Does not fire change event.