Package org.dellroad.stuff.pobj

Class FilterDelegate<T>

java.lang.Object
org.dellroad.stuff.pobj.FilterDelegate<T>
Type Parameters:
T - type of the root persistent object
All Implemented Interfaces:
PersistentObjectDelegate<T>
public class FilterDelegate<T> extends Object implements PersistentObjectDelegate<T>
Adapter class for PersistentObjectDelegate implementations that wrap a nested delegate. All methods in this class forward to the nested delegate.

  • Field Details

  • Constructor Details

  • Method Details

    • serialize

      public void serialize(T obj, Result result) throws IOException
      Description copied from interface: PersistentObjectDelegate
      Serialize a root object graph into XML.

      Note that this method effectively defines what is contained in the object graph rooted at obj.

      This method must not modify obj or any other object in its object graph.

      Specified by:
      serialize in interface PersistentObjectDelegate<T>
      Parameters:
      obj - object to serialize; must not be modified
      result - XML destination
      Throws:
      IOException - if an I/O error occurs

    • deserialize

      public T deserialize(Source source) throws IOException
      Description copied from interface: PersistentObjectDelegate
      Deserialize a root object graph from XML.

      This method also presents an opportunity to (re)construct any indexes used for optimizing queries into the root object graph.

      Specified by:
      deserialize in interface PersistentObjectDelegate<T>
      Parameters:
      source - XML source
      Returns:
      deserialized object
      Throws:
      IOException - if an I/O error occurs

    • copy

      public T copy(T original)
      Description copied from interface: PersistentObjectDelegate
      Make a deep copy of the given object.

      For correct behavior, this behavior of this method should be equivalent to a serialization followed by a deserialization.

      This method must not modify original or any other object in its object graph.

      Specified by:
      copy in interface PersistentObjectDelegate<T>
      Parameters:
      original - original object
      Returns:
      deep copy of the object graph rooted at original

    • isSameGraph

      public boolean isSameGraph(T root1, T root2)
      Description copied from interface: PersistentObjectDelegate
      Attempt to determine whether two object graphs are identical.

      This optional method is an optimization to detect invocations to PersistentObject.setRoot() where the new object graph and the old object graph are identical. In such cases, no change is applied, the version number does not increase, and no notifications are sent.

      It is always safe and correct for this method to return false. If it returns true, then it must be the case that the two object graphs are identical.

      This method must not modify oldRoot or newRoot or any other object in their object respective graphs.

      Specified by:
      isSameGraph in interface PersistentObjectDelegate<T>
      Parameters:
      root1 - root of first object graph
      root2 - root of second object graph
      Returns:
      true if root1 and root2 represent equal object graphs

    • validate

      public Set<jakarta.validation.ConstraintViolation<T>> validate(T obj)
      Description copied from interface: PersistentObjectDelegate
      Validate the given object.

      This method must not modify obj or any other object in its object graph.

      Specified by:
      validate in interface PersistentObjectDelegate<T>
      Parameters:
      obj - root object
      Returns:
      set of zero or more constraint violations

    • handleWritebackException

      public void handleWritebackException(PersistentObject<T> pobj, Throwable t)
      Description copied from interface: PersistentObjectDelegate
      Handle an exception thrown during a write-back attempt. ThreadDeath exceptions are not passed to this method, but all others are.
      Specified by:
      handleWritebackException in interface PersistentObjectDelegate<T>
      Parameters:
      pobj - the instance that encountered the exception
      t - the exception thrown

    • getDefaultValue

      public T getDefaultValue()
      Description copied from interface: PersistentObjectDelegate
      Get the default value for the root object graph. This method is invoked at startup when the persistent file does not exist. If this method returns null, then an empty start occurs unless the PersistentObject object is configured to disallow them, in which case an exception is thrown.
      Specified by:
      getDefaultValue in interface PersistentObjectDelegate<T>
      Returns:
      root object initial value, or null if there is no default value