i3.dragos.gm.core.schema
Interface ExistenceCheckable

All Known Subinterfaces:

Attribute, Edge, EdgeClass, Graph, GraphClass, GraphEntity, GraphEntityClass, Node, NodeClass, Relation, RelationClass, RelationEnd, RelationEndClass

All Known Implementing Classes:

AbstractAttribute, AttributeProxy, EdgeClassProxy, EdgeProxy, GraphClassProxy, GraphEntityClassProxy, GraphEntityProxy, GraphProxy, NodeClassProxy, NodeProxy, RelationClassProxy, RelationEndClassProxy, RelationEndProxy, RelationProxy

public interface ExistenceCheckable

Methods for verifying the existence of referenced objects. See the "Consistency" chapter in the documentation for details.

Author:

Thorsten Hermes <thermes@i3.informatik.rwth-aachen.de>

Method Summary

void	checkExistence() Checks whether this object still exists, throwing an exception if not.
void	checkExistenceOptional() Checks whether this object still exists, throwing an exception if not.

Method Detail

checkExistence

void checkExistence()
                    throws java.lang.RuntimeException

Checks whether this object still exists, throwing an exception if not. This method should be called by all writing operations.

Throws:

java.lang.RuntimeException - if this object no longer exists or an error occurred while accessing the GraphPool.

checkExistenceOptional

void checkExistenceOptional()
                            throws java.lang.RuntimeException

Checks whether this object still exists, throwing an exception if not. This method should be called by all reading operations.

A useful default implementation would be as follows:

 try {
     GraphPool gp = GraphPoolFactory.get(getDataSourceURL());
     if (gp.getForceExistenceCheckOnRead()) {
         checkExistence();
     }
 } catch (DragosException e) {
     String message = "Caught GraphPoolException while trying to determine whether to perform checks on read operation!";
     log.error(message);
     throw new RuntimeException(message);
 }
 

Throws:

java.lang.RuntimeException - if this object no longer exists or an error occurred while accessing the GraphPool.