oracle.toplink.ejb.cmp
Class SessionAccessor

java.lang.Object
  oracle.toplink.ejb.cmp.SessionAccessor

public class SessionAccessor
extends java.lang.Object

This class provides access to TopLink's Session and UnitOfWork and can be used at runtime by a bean to manage aspects of caching, merging, and transactions with regular java objects that are not generally available in an EJB.

If a bean (including an EJB1.1 bean) has references to regular Java objects that are made persistent through TopLink, this class can be used to properly manage various serialized versions of the Java objects.

Constructor Summary

SessionAccessor()

Method Summary

static UnitOfWork	getCurrentUnitOfWorkFor(javax.ejb.EntityContext context) Returns the active TopLink unit of work for the context.
static Session	getSessionFor(javax.ejb.EntityContext context) Returns the active TopLink session for the context.
static Session	getSessionFor(java.lang.String name) Returns the active TopLink session for the project.
static java.lang.Object	registerOrMergeAttribute(java.lang.Object value, java.lang.String attributeName, javax.ejb.EntityContext ctx) Merge the changes from the remote clone into the server version of the object(s) for a bean's attribute.
static java.lang.Object	registerOrMergeObject(java.lang.Object value, javax.ejb.EntityContext ctx) Merge the changes from the remote clone into the server version of the object(s) for a bean's attribute.

Methods inherited from class java.lang.Object

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

Constructor Detail

SessionAccessor

public SessionAccessor()

Method Detail

getCurrentUnitOfWorkFor

public static UnitOfWork getCurrentUnitOfWorkFor(javax.ejb.EntityContext context)

Returns the active TopLink unit of work for the context. This can be accessed to give access to advanced TopLink API on the server.

WARNING - Only in rare instances should this method ever be used, and if so, caution must be taken to ensure that the unit of work is not misused.

Parameters:

context - the entity context for the bean

Returns:

The unit of work active for this bean

getSessionFor

public static Session getSessionFor(javax.ejb.EntityContext context)

Returns the active TopLink session for the context. This can be accessed to give access to advanced TopLink API on the server.

Parameters:

context - the entity context associated with the session

Returns:

The Session used by all of the descriptors in the project

getSessionFor

public static Session getSessionFor(java.lang.String name)

Returns the active TopLink session for the project. This can be accessed to give access to advanced TopLink API on the server.

Parameters:

name - the project identifier of the project associated with the session

Returns:

The Session used by all of the descriptors in the given project

registerOrMergeObject

public static java.lang.Object registerOrMergeObject(java.lang.Object value,
                                                     javax.ejb.EntityContext ctx)

Merge the changes from the remote clone into the server version of the object(s) for a bean's attribute. The object should not be a collection.

Here is an example of how this method can be used within an EJB setter method.

    public void setAddress(Address addressFromClient) {
        this.address = (Address)SessionAccessor.registerOrMergeObject(
            addressFromClient, this.ctx
        );
    }
 

Parameters:

value - the attribute object to merge

ctx - the entity context of the bean

Returns:

The merged object

registerOrMergeAttribute

public static java.lang.Object registerOrMergeAttribute(java.lang.Object value,
                                                        java.lang.String attributeName,
                                                        javax.ejb.EntityContext ctx)

Merge the changes from the remote clone into the server version of the object(s) for a bean's attribute.

Here is an example of how this method can be used within an EJB setter method.

    public void setAddress(Address addressFromClient) {
         this.address = SessionAccessor.registerOrMergeAttribute(
             addressFromClient, "address", this.ctx
         );
    }
 

Parameters:

value - the attribute object to merge

attributeName - the name of the field in the bean

ctx - the entity context of the bean

Returns:

The merged object