com.evermind.server.ejb
Interface FieldPersistenceManager

public interface FieldPersistenceManager

A FieldPersistenceManager handles persistence of one in a CMP entity. It is used when providing custom persistence algorithms, an example could be an int value stored as a hex string in the database.

Here is a sample config for using a FieldPersistenceManager in orion-ejb-jar.xml:
<cmp-field-mapping name="aField" persistence-name="aField">
<field-persistence-manager class="com.evermind.server.ejb.StringFieldPersistenceManager" />
</cmp-field-mapping>

The configuration can also define extra properties for advanced managers.
The default properties that are always supplied are:
name - the name of the CMP field.
persistenceName - the specified persistence-name.
persistenceType - the specified persistence-type if any.

Combo field managers (storing to 2+ database table fields) would need to use additional properties.

Method Summary

java.lang.Object	get(java.sql.ResultSet set) Performs a 'read' operation to retrieve the handled field.
java.util.Map	getColumns() Requests the database columns used by this manager.
java.util.Properties	getProperties() Retrieves the properties, possibly updated by the manager (cleaned up, altered).
void	init(java.util.Properties properties) Initializes the manager with the supplied properties.
void	set(java.sql.PreparedStatement statement, int columnID, java.lang.Object value) Performs a 'write' operation to persist the handled field.

Method Detail

init

public void init(java.util.Properties properties)
          throws java.lang.InstantiationException

Initializes the manager with the supplied properties.

get

public java.lang.Object get(java.sql.ResultSet set)
                     throws java.sql.SQLException

Performs a 'read' operation to retrieve the handled field. The name to use for ResultSet operations is supplied in the properties in init(...). High performance managers may also provide a getPrimitive(ResultSet set) for primitive types.

set

public void set(java.sql.PreparedStatement statement,
                int columnID,
                java.lang.Object value)
         throws java.sql.SQLException

Performs a 'write' operation to persist the handled field. The columnID is the first ID used by the (possible combo-field) handler. The value is the field's value, converted to Object form if needed. (int -> Integer, etc). A special case is if the handler class has defined a public void set(PreparedStatement statement, int columnID, value) and the field is of a primitive type. In that case that method will be called instead. This is purely an optimization for advanced handlers.

getColumns

public java.util.Map getColumns()

Requests the database columns used by this manager. Returns an empty Map if no columns are used and a set of persistence-name -> persistence-type mappings otherwise.

getProperties

public java.util.Properties getProperties()

Retrieves the properties, possibly updated by the manager (cleaned up, altered).