javax.portlet
public interface PortletPreferences
PortletPreferences
interface allows the portlet to store
configuration data. It is not the
purpose of this interface to replace general purpose databases.
There are two different types of preferences:
EDIT, HELP, VIEW
).
Per default every preference is modifiable.
read-only
set to true
,
or if the portlet container restricts write access.
Changes are persisted when the store
method is called. The store
method
can only be invoked within the scope of a processAction
call.
Changes that are not persisted are discarded when the
processAction
or render
method ends.
Method Summary | |
---|---|
Map | getMap()
Returns a Map of the preferences.
|
Enumeration | getNames()
Returns all of the keys that have an associated value,
or an empty Enumeration if no keys are
available.
|
String | getValue(String key, String def)
Returns the first String value associated with the specified key of this preference.
|
String[] | getValues(String key, String[] def)
Returns the String array value associated with the specified key in this preference.
|
boolean | isReadOnly(String key)
Returns true, if the value of this key cannot be modified by the user.
|
void | reset(String key)
Resets or removes the value associated with the specified key.
|
void | setValue(String key, String value)
Associates the specified String value with the specified key in this
preference.
|
void | setValues(String key, String[] values)
Associates the specified String array value with the specified key in this
preference.
|
void | store()
Commits all changes made to the preferences via the
set methods in the persistent store.
|
Map
of the preferences.
The values in the returned Map
are from type
String array (String[]
).
If no preferences exist this method returns an empty Map
.
Returns: an immutable Map
containing preference names as
keys and preference values as map values, or an empty Map
if no preference exist. The keys in the preference
map are of type String. The values in the preference map are of type
String array (String[]
).
Enumeration
if no keys are
available.
Returns: an Enumeration of the keys that have an associated value,
or an empty Enumeration
if no keys are
available.
Parameters: key key for which the associated value is to be returned def the value to be returned in the event that there is no
value available associated with this key
.
Returns: the value associated with key
, or def
if no value is associated with key
, or the backing
store is inaccessible.
Throws: java.lang.IllegalArgumentException
if key
is null
. (A
null
value for def
is permitted.)
See Also: (String, String[])
Returns the specified default if there is no value associated with the key, or if the backing store is inaccessible.
If the implementation supports stored defaults and such a default exists and is accessible, it is used in favor of the specified default.
Parameters: key key for which associated value is to be returned. def the value to be returned in the event that this
preference node has no value associated with key
or the associated value cannot be interpreted as a String array,
or the backing store is inaccessible.
Returns: the String array value associated with
key
, or def
if the
associated value does not exist.
Throws: java.lang.IllegalArgumentException if key
is null
. (A
null
value for def
is permitted.)
See Also: getValue
Modifiable preferences can be changed by the
portlet in any standard portlet mode (EDIT, HELP, VIEW
).
Per default every preference is modifiable.
Read-only preferences cannot be changed by the
portlet in any standard portlet mode, but inside of custom modes
it may be allowed changing them.
Preferences are read-only, if they are defined in the
deployment descriptor with read-only
set to true
,
or if the portlet container restricts write access.
Returns: false, if the value of this key can be changed, or if the key is not known
Throws: java.lang.IllegalArgumentException
if key
is null
.
If this implementation supports stored defaults, and there is such a default for the specified preference, the given key will be reset to the stored default.
If there is no default available the key will be removed.
Parameters: key to reset
Throws: java.lang.IllegalArgumentException if key is null
. ReadOnlyException
if this preference cannot be modified for this request
The key cannot be null
, but null
values
for the value parameter are allowed.
Parameters: key key with which the specified value is to be associated. value value to be associated with the specified key.
Throws: ReadOnlyException
if this preference cannot be modified for this request java.lang.IllegalArgumentException if key is null
,
or key.length()
or value.length
are to long. The maximum length
for key and value are implementation specific.
See Also: (String, String[])
The key cannot be null
, but null
values
in the values parameter are allowed.
Parameters: key key with which the value is to be associated values values to be associated with key
Throws: java.lang.IllegalArgumentException if key is null
, or
key.length()
is to long or value.size
is to large. The maximum
length for key and maximum size for value are implementation specific. ReadOnlyException
if this preference cannot be modified for this request
See Also: setValue
set
methods in the persistent store.
If this call returns succesfull, all changes are made persistent. If this call fails, no changes are made in the persistent store. This call is an atomic operation regardless of how many preference attributes have been modified.
All changes made to preferences not followed by a call
to the store
method are discarded when the
portlet finishes the processAction
method.
If a validator is defined for this preferences in the
deployment descriptor, this validator is called before
the actual store is performed to check wether the given
preferences are vaild. If this check fails a
ValidatorException
is thrown.
Throws: java.io.IOException if changes cannot be written into the backend store ValidatorException if the validation performed by the associated validator fails java.lang.IllegalStateException if this method is called inside a render call
See Also: PreferencesValidator