Configuring Copy Policy

The TopLink unit of work feature must be able to produce an exact copy (clone) persistent objects. Table 28-32 summarizes which descriptors support a copy policy.

Table 28-32 Configuring Descriptors with a Copy Policy

Descriptor	Using TopLink Workbench	Using Java
Relational Descriptors
Object-Relational Descriptors
EIS Descriptors
XML Descriptors

TopLink supports two ways of copying objects:

• Instantiation policy: By default, TopLink creates a new copy of an object by using the currently configured instantiation policy (see "Configuring Instantiation Policy").

• Method: TopLink creates a new copy of an object by calling a method on the object that you specify. For example, you can specify the object's clone method (or any other appropriate method on the object).

Using TopLink Workbench

To specify the copy policy for a descriptor, use this procedure:

1. Select a descriptor in the Navigator. Its properties appear in the Editor.

   If the Copying advanced property is not visible for the descriptor, right-click the descriptor and choose Select Advanced Properties > Copying from the context menu or from the Selected menu.

2. Click the Copying tab in the Editor.

   Figure 28-41 Copying Tab

   
   

Use the following information to enter data in each field on the tab:

Field	Description
Use Instantiation Policy	Creates a new instance of the object using the descriptor's instantiation policy (see "Configuring Instantiation Policy").
Use Clone Method	Specifies whether or not to call the clone method of the object. Select a method from the list.

Using Java

Use one of the following ClassDescriptor methods to set the appropriate type of copy policy:

• useCloneCopyPolicy(): the object must provide a clone method

• useCloneCopyPolicy(java.lang.String cloneMethodName)

• useInstantiationCopyPolicy()