The representation (mapping) in the JavaTM
programming language of an SQL BLOB value to an array of bytes.
A ByteArrayBlob contains an internal buffer that contains bytes that may be
read from the stream.
JDBCActivateEntityCommand initializes the entity persistence context.
For cmp 1.x it creates a place to store original values for dirty checking.
In CMP2.x it creates a place to store the actual value.
The role of this interceptor relationship messages from a related CMR field
and invoke the specified message on this container's cmr field of the
relationship.
Generally, implementations of this interface map instances of one Java type
into instances of another Java type.
Mappers are used in cases when instances of "enum" types are used as CMP
field values.