Class AbstractPreferenceStorage


  • public abstract class AbstractPreferenceStorage
    extends Object
    Abstract class which can be used to help provide an alternate storage mechanism for Eclipse preferences. Clients can over-ride this class and implement the appropriate methods to read/persist preferences.
    Since:
    3.5
    • Constructor Detail

      • AbstractPreferenceStorage

        public AbstractPreferenceStorage()
    • Method Detail

      • load

        public abstract Properties load​(String nodePath)
                                 throws BackingStoreException
        Return a java.util.Properties object containing the preference key/value pairs for the preference node with the specified path, and its children.

        The table keys consist of an optional child node path and separator, followed by the property key. The table values are the values of the properties.

             [childNodePath/]propertyKey=propertyValue
         

        Note: Whether they are absolute or relative, the paths in the returned Properties object are always interpreted as relative to the node specified by nodePath.

        Parameters:
        nodePath - the absolute path of the preference node
        Returns:
        a java.util.Properties object or null
        Throws:
        BackingStoreException - if there was a problem loading the properties
      • save

        public abstract void save​(String nodePath,
                                  Properties properties)
                           throws BackingStoreException
        Save the given java.util.Properties object which represents preference key/value pairs for the preference node represented by the given path.

        Clients are reminded that if the given properties object is empty then the preference node has been removed and they should react accordingly (e.g. for instance by removing the file on disk)

        Parameters:
        nodePath - the absolute path of the preference node
        properties - the java.util.Properties object to store
        Throws:
        BackingStoreException - if there was a problem saving the properties
      • loadProperties

        protected Properties loadProperties​(InputStream input)
                                     throws BackingStoreException
        Helper method to load a java.util.Properties file from the given input stream. The stream will be closed on completion of the operation.
        Parameters:
        input - the stream to load from
        Returns:
        the java.util.Properties object loaded from the stream
        Throws:
        BackingStoreException - if there was a problem loading the file
      • saveProperties

        protected void saveProperties​(OutputStream output,
                                      Properties properties)
                               throws BackingStoreException
        Helper method to save the given java.util.Properties object to the given output stream. The stream will be closed at the end of the operation.
        Parameters:
        output - the stream to store the object to
        properties - the object to store
        Throws:
        BackingStoreException - if there was a problem saving the object
      • childrenNames

        public abstract String[] childrenNames​(String nodePath)
                                        throws BackingStoreException
        Return a string array containing the names of the children for the node with the given path. If there are no children then an empty array is returned. One example where this method is commonly called, is at the scope root when discovering the initial children.
        Parameters:
        nodePath - the path for the preference node
        Returns:
        the array of children names
        Throws:
        BackingStoreException - if there was a problem retrieving the child names
      • removed

        public abstract void removed​(String nodePath)
        Callback to inform the client that the preference node with the specified path has been deleted and the client should react accordingly and make the appropriate changes to the storage. (e.g. delete the file/information associated with that node)
        Parameters:
        nodePath - the absolute path of the preference node