org.eclipse.persistence.dynamic

Interface DynamicEntity

public interface DynamicEntity

DynamicEntity is the public interface for dealing with dynamic persistent objects.

The purpose of dynamic persistent objects is to enable (simple) data access when only mapping information is available
and no concrete Java model is present (specifically, no .class files .)

Applications using DynamicEntity's can access the persistent state using property names which correspond
to the mapped attributes in the underlying EclipseLink descriptors. For properties mapped to containers (Collection,
Map, etc.), the property is retrieved then the resulting container can be manipulated.

     ...
     DynamicEntity de = ...; // retrieve from database
     Collection<String> myListOfGroups = de.<Collection<String>>get("myListOfGroups");
     if (!myListOfGroups.isEmpty()) {
        myListOfGroups.add("FabFour");
     }
 

To discover meta-data about a DynamicEntity's properties, see the DynamicHelper class

Author:

dclarke, mnorman

Since:

EclipseLink 1.2

Method Summary

Modifier and Type	Method and Description
<T> T	get(java.lang.String propertyName) Return the persistence value for the given property as the specified type.
boolean	isSet(java.lang.String propertyName) Discover if a property has a persistent value
DynamicEntity	set(java.lang.String propertyName, java.lang.Object value) Set the persistence value for the given property to the specified value

Method Detail

get

<T> T get(java.lang.String propertyName)
   throws DynamicException

Return the persistence value for the given property as the specified type. In the case of relationships, this call will populate lazy-loaded relationships

Type Parameters:

T - generic type of the property (if not provided, assume Object). If the property cannot be cast to the specific type, a DynamicExceptionwill be thrown.

Parameters:

propertyName - the name of a mapped property If the property cannot be found, a DynamicException will be thrown.

Returns:

persistent value or relationship container of the specified type

Throws:

DynamicException

set

DynamicEntity set(java.lang.String propertyName,
                  java.lang.Object value)
           throws DynamicException

Set the persistence value for the given property to the specified value

Parameters:

propertyName - the name of a mapped property If the property cannot be found, a DynamicException will be thrown.

value - the specified object

Returns:

the same DynamicEntity instance

Throws:

DynamicException

isSet

boolean isSet(java.lang.String propertyName)
       throws DynamicException

Discover if a property has a persistent value

Parameters:

propertyName - the name of a mapped property If the property cannot be found, a DynamicException will be thrown.

Returns:

true if the property has been set

Throws:

DynamicException