org.tentackle.persist

Class PersistenceVisitor

java.lang.Object

org.tentackle.reflect.ReflectiveVisitor

org.tentackle.persist.PersistenceVisitor

All Implemented Interfaces:

Serializable

Direct Known Subclasses:

IgnoreDuplicatesPersistenceVisitor

public abstract class PersistenceVisitor
extends ReflectiveVisitor
implements Serializable

A reflective visitor to add application-specific functionality to persistence operations.

Visitors can be registered at a Db and are only valid within a single transaction. If present, the visitors will be consulted before each persistence operation such as ModificationLog.INSERT, ModificationLog.UPDATE or ModificationLog.DELETE, whether the operation is allowed or should be silently skipped.

The methods are invoked in the following order:

1. visit(org.tentackle.db.DbObject, Character) which in turn invokes the type-specific visit method
2. isPersistenceOperationAllowed(org.tentackle.db.DbObject, char)

A visitor may also throw a PersistenceException if the operation must not continue.

The effective visit method for the concrete persistence class is determined by reflection. The most specific method will be used, which allows to use a method for a class hierarchy.

Notice that the visit method must use a Character instead of char to be found by the method dispatcher.

Author:

harald

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
PersistenceVisitor()

Method Summary

Modifier and Type	Method and Description
boolean	isPersistenceOperationAllowed(AbstractDbObject<?> object, char modType) Checks if the persistence operation is allowed.

Methods inherited from class org.tentackle.reflect.ReflectiveVisitor

findVisitMethod, handleException, isImplementedClass, visit

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

PersistenceVisitor

public PersistenceVisitor()

Method Detail

isPersistenceOperationAllowed

public boolean isPersistenceOperationAllowed(AbstractDbObject<?> object,
                                             char modType)

Checks if the persistence operation is allowed.

Parameters:

object - the persistable object

modType - the modification type

Returns:

true if allowed