Package org.eclipse.rap.rwt.service

Interface SettingStore

All Known Implementing Classes:
FileSettingStore
public interface SettingStore
A setting store is a persistent store for user-specific settings (i.e. key/value pairs). The data in this store is kept beyond the scope of a single session.

A setting store instance is always associated with the current user session. Any settings being put into the store (via setAttribute(String, String)) are considered persisted from that point on.

To retrieve data stored in a previous session, a client can invoke the method loadById(String) with the ID of the session to load into the store. This will load any data stored under that id into the current setting store.

The framework will assign a new setting store to each new UI session, based on the current session id. After the user has authenticated, application developers can use the loadById(String) method to initialize the store with persisted data stored under that id during a previous session. Obviously, any data that is set into the store from that point on, will also be persisted under the current id and will also be available in the future.

Custom setting store implementations are supported, those must provide a corresponding SettingStoreFactory.

Since:
2.0
See Also:

  • Method Details

    • getAttribute

      String getAttribute(String name)
      Returns the attribute stored under the specified name in this setting store.
      Parameters:
      name - a non-null String specifying the name of the attribute
      Returns:
      the attribute stored under the given name or null if no attribute is stored under that name

    • getAttributeNames

      Enumeration<String> getAttributeNames()
      Returns an Enumeration of strings with the names of all attributes in this setting store.
      Returns:
      an enumeration with the attribute names in this setting store, never null

    • setAttribute

      void setAttribute(String name, String value) throws IOException
      Stores a given attribute in this setting store, using the name specified. If an attribute with the same name is already stored in this setting store, the previous value is replaced. The attribute is considered persisted when after this method completes.

      If the value is null, this has the same effect as calling removeAttribute(String).

      SettingStoreListeners attached to this instance will be notified after an attribute has been stored.

      Parameters:
      name - the name of the attribute, must not be null or empty
      value - the attribute to store, may be null
      Throws:
      IOException - if the load operation failed to complete normally

    • removeAttribute

      void removeAttribute(String name) throws IOException
      Removes the attribute stored under the specified name from this setting store. If no attribute is stored under the specified name, this method does nothing.

      SettingStoreListeners attached to this instance will be notified after an attribute has been removed.

      Parameters:
      name - the name of the attribute to remove, must not be null
      Throws:
      IOException - if the remove operation failed to complete normally

    • loadById

      void loadById(String id) throws IOException
      Replaces the contents of this setting store with the persisted contents associated with the given ID.

      The attributes of this setting store will remain associated with the old id, but will be removed from this store instance. SettingStoreListeners attached to this store will receive a notification for each removed attribute.

      During the load operation this store will be filled with the attributes associated with the new ID. SettingStoreListeners attached to this store will receive a notification for each added attribute.

      After the load operation this store will only hold attributes associated with the new id value.

      Parameters:
      id - the ID of the settings to load, must not be null or empty
      Throws:
      IOException - if the load operation failed to complete normally
      IllegalArgumentException - if the given id is empty

    • getId

      String getId()
      Returns the unique identifier of this setting store.
      Returns:
      a non-empty string, never null

    • addSettingStoreListener

      void addSettingStoreListener(SettingStoreListener listener)
      Attaches the given listener to this setting store. Listeners will be notified of changes in the store. If the listener has already been added to this store, this method does nothing.
      Parameters:
      listener - the listener to add, must not be null

    • removeSettingStoreListener

      void removeSettingStoreListener(SettingStoreListener listener)
      Removes the given listener from this setting store. If the listener has not been added, this method does nothing.
      Parameters:
      listener - the listener to remove, must not be null